Prepared by
Forrest M. Council
University of North Carolina
Highway Safety Research Center
730 Martin Luther King Jr Blvd, Suite 300, CB #3430
NC 27599-3430
and
Anusha patel Nujjetty
Yusuf M. Mohamedshah
LENDIS Corporation
Turner-Fairbank Highway Research Center
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101
Prepared for
Federal Highway Administration
Office of Safety and Traffic Operations Research & Development
U.S. Department of Transportation
Washington, DC 20590
Revised, February 2014
The North Carolina database incorporated into HSIS contains four different files --accident characteristics, vehicles in the accidents, occupants in the vehicles, and roadway inventory (which includes AADT data). Before 2000, the data was derived from the “MERGE” system, a mainframe database maintained by the NCDOT. Since 2000, the three crash subfiles have been derived from the “NCDMV” system maintained by the NC Department of Motor Vehicles (DMV) while the roadway inventory file has been provided by the NCDOT GIS section.
For ease of use, the three accident subfiles and the Roadlog File have been converted to SAS files in HSIS. Raw file data provided to the Highway Safety Research Center (HSRC) are retained as backup information. The documentation (variable listings, definitions, etc.) for these raw files and for the SAS files that are developed from them are available at Federal Highway Administration (FHWA) offices.
Beginning in 2004, the HSIS system was converted from a SYBASE relational database to an ORACLE relational database for internal use. Data files for a given State are linked and manipulated by HSIS staff using SAS code and, as in the past, we have continued to produce SAS format libraries for each of the variables in each of the files. This Guidebook will concern these SAS files - their formats, completeness, and quality. However, researchers requesting data from HSIS can request the output in various formats such as SAS, Microsoft Excel® and Access®, dBase, ASCII, etc.
As noted above, the accident data are divided into three separate subfiles. The first containing the basic accident information on a case by case basis, the second containing information up to 15 vehicles in each accident, and a third containing all occupants in each of the 15 possible vehicles. The vehicle and occupant data can be linked to the basic accident file for a specific case using the accident report number. The accident subfile can be linked to the Roadway Inventory File using a county/route/milepost variable.
Unlike the accident file, which is referenced to a point on the roadway, each record in the Roadway Inventory File contains information on a homogeneous section of roadway (i.e., a stretch of road which is consistent in terms of certain characteristics, with a new section being defined each time any of the characteristics changes). Each record on the basic inventory file contains current characteristics of the roadway system, and includes such variables as surface width, lane width and type, shoulder width and type, median information and other variables. This file also contains information on traffic volumes -- AADT and some data on total percent trucks and truck percent during peak time periods.
Details of the files noted above are included in the following sections.
Accident data are collected statewide by all police departments in North Carolina on a standard form as prescribed by state law. The prescribed accident-reporting threshold is currently personal injury or $1,000 property damage. Prior to 1996, the crash-reporting threshold was $500. It is felt that this threshold is generally used for all accidents occurring on the entire North Carolina roadway system, both in rural and urban areas. It is probably more consistently followed in the rural areas where the State Highway Patrol does most of the reporting. However, it is a feeling of North Carolina data users that the overwhelming majority of municipal police agencies also follow the same reporting threshold.
There are currently approximately 280,000 accidents in the entire state each year. For each crash that is investigated, an accident report form is sent to the North Carolina Department of Motor Vehicles (DMV) Accident Reports Division, the central repository of the accident data. The DMV is responsible for coding and keypunching all of the information on the form, including the data used in locating the accident to the roadway system. Of the 230,000 accidents that are keypunched each year, approximately 70% of these are linkable with the Roadway Inventory File. Note that the non-linkable accidents are primarily those occurring on city streets that are not part of the “state system”. The number of linkable accidents has increased considerably from 2003 onwards. This is because the number of inventoried miles to which crashes can be mileposted has increased. Hence, for 2012, HSIS has about 144,000 crashes that are linkable to the roadway inventory. Before 2003, the number of linkable crashes was significantly lower (about 100,000 in 2000 and about 95,000 in 1997). The HSIS currently includes data from 1990 through 2012.
In terms of coding accident location, the North Carolina system is different than many of the other state systems. The crash location system is a county/route/milepost system, which is based on a computerized (non-physically mileposted) “paper” reference system. The Department of Motor Vehicles types the basic location information provided by the investigating officer. This includes the route, on which the accident occurred, and a distance and a direction to a reference point such as an intersecting roadway, a bridge, or a city boundary. The computer then assigns a milepost based on these data. In providing their location information, police officers are asked to report distance to the nearest one- tenth of a mile in rural areas when the crash is not at or near an intersection. If an accident occurs within 500 feet of an intersection, the distance is to be reported in feet. In urban areas, locations are generally provided in feet from a nearby intersection. There is some indication that the “less than 500 feet” criterion is not always followed for rural intersections. It is felt by NC DOT and other users that approximately 80 to 90 percent of the mileposted accidents on state-system roads in urban areas are correctly mileposted within 100 feet of their true location. Similarly, it is felt that approximately 80% of those in rural areas are mileposted within a tenth of a mile of their true location.
Of the 79,000 miles of roadway on the North Carolina state system, approximately 39,000 miles are included in this computerized reference system until 2001. Accidents could only be located to these 39,000 miles of roadway. For 2002 – 2008, between 60,000 and 70,000 miles are included, resulting in a significant increase in linkable accidents (i.e., approximately 140,000 annually). For 2009 and later, the number of total linkable miles increased to approximately 78,000. However, due to changes in the AADT assignment procedures, the number of linkable miles with AADT decreased to 27,000 in 2009 and 2010 and 43,000 in 2011 and later. The numbers of linkable crashes decreased to 132,000 in 2009-10 and 144,000 in 2011 and later. (It is noted that the 27,000 miles in 2009 and 2010 is still larger than the inventoried and mileposted systems in most states within HSIS). The linkable routes include all Interstate, U.S., and N.C. routes, and major secondary routes (down through collectors) in both rural and urban areas. While AADTs were estimated for a large number of urban and rural roads classified as “local” prior to 2009, they were only estimated for a limited sample of these local roads in 2009 and later. Thus, the un-linkable miles are predominantly secondary roads in rural areas and city streets in urban areas. (Note that there are no "county roads" in North Carolina since all except for non-system city streets are under State control.) Some accidents on primary routes in urban areas cannot be mileposted due to changes in street names, which have not been updated in the computerized mileposting program.
As indicated above, North Carolina is in the process of updating its accident record system by converting to a relational database. An important component of this modified system will be the ability for users of the data (e.g., Traffic Safety Systems Section staff) to make online corrections to accident locations in their use of hard copies.
The North Carolina accident file contains the basic variables found on most state accident files, with some important additions. There is both a first harmful event and a most harmful event variable, allowing one to better correlate injury to specific type of impact. Unlike other HSIS states, North Carolina accident files from 2000 onwards have some work zone related variables which allows one to locate a crash in relation to the location in the work zone and whether the work zone was marked or not.
The Vehicle file contains approximately 250,000 vehicles each year. As in accident file, the number of vehicles for 2002 – 2008 reflects the higher number of crashes that are present for these years because of a higher number of linkable roads. Unlike any other HSIS state, information on truck trailer width and length and total truck length is captured from the accident report form. This allows for categorizations of truck data not usually possible in most state truck files. There is a rollover variable that is separate from all other variables and specific to each vehicle, allowing one to separate rollover from both the type of accident and from impact with fixed objects. This allows the study of rollover as a result of other impacts, such as impacts with fixed objects. There is an officer judgment related to “drivability” of the vehicle, which can be used as a towaway threshold in certain analyses. From 2000 onwards, there are event variables in the vehicle file, which allows one to examine the sequence of events of an accident. Finally, there is also an indicator of airbag deployment. Note that due to change in reporting practices from 2000 onwards some variables were dropped and some new variables were added. A NOTE is added under such variables in the format section of the guidebook.
It should also be noted that the North Carolina Vehicle subfile did not contain detailed elements on large truck crashes proposed by the National Governor's Association (NGA) until 2000. In 1999 and earlier, supplemental NGA data were collected by some officers (primarily State Highway Patrol officers) on truck crashes on a supplemental report form. These data are submitted to the Truck Enforcement Unit at the Division of Motor Vehicles for computerization. Unfortunately, no standard accident number is available to link these data with the standard Accident File. However, in 2000, the accident report form was modified to include virtually all of the NGA-specified variables. Thus, these truck-related data are in the 2000 and later accident files.
The Occupant subfile includes information on all occupants in a vehicle, whether injured or not. This file contains approximately 350,000 occupants each year after 2002, and includes standard variables related to seating positions, sex, race, and injury. As with most other states, the injury variable in North Carolina is the KABCO system, which provides police estimates of injury level.
In general, the severity of crashes in North Carolina is somewhat more severe than in the other HSIS states, with more injury crashes and a lower percentage of PDOs. This probably stems from the fact that North Carolina is somewhat rural, as reflected by the slightly higher proportion of crashes in rural areas.
Tabulations were run to examine the question of reporting completeness and data quality for accident, vehicle, and occupant variables. Here, study of percent of “unknown,” “not applicable,” and “not stated” values for all key variables found in these files indicates that, in general, the data are quite complete. In most cases, non-coding occurs in less than one percent of the cases. For variables in which the percentage of non-coding is somewhat higher, a "NOTE" has been included under that variable listing in the later format sections of this Guidebook.
To assess the accuracy of the accident variables (and the variables in the other files), we questioned users of the data and examined and compared certain single variable tables. In North Carolina, we questioned staffs in the Management Information Systems office who maintain the computerized files, the Traffic Safety Systems Section who use the data in various hazardous location analyses and other evaluations, and the Highway Safety Research Center staff who have used the data for more than thirty years in a variety of analysis efforts. The staff were interviewed concerning variables they feel are incompletely coded or that might be inaccurate. In general, most indicated that they felt that almost all the variables on the file were accurately coded. It is obvious that the “occupant restraint use” variable on the file is inaccurate, in that regularly conducted field observations of use indicate figures which are at least 10 to 15 percent lower than the values found in the accident file. (This is felt to be the case in accident-based measures of occupant restraint use in all states systems, particularly in states with a strong belt-use law which will cause drivers to report to the investigating officer that they have used the belt whether they have or not).
Prior to 2010, the roadway inventory information was the responsibility of the Roadway Inventory Section, GIS Branch, of the NC Division of Highways. In 2010, the inventory information became the responsibility of the Inventory and Assessments unit within the Division of Highways. The traffic volume data is the responsibility of the Traffic Survey Group. Both units provide their data to the GIS Unit, who compiles and distributes the combined inventory and AADT data in quarterly releases. HSIS staff downloads the first-quarter release each year and uses the inventory data as the end-of-year file for the previous year (e.g., the first-quarter 2013 data are used as the 2012 HSIS file.) The AADT for the previous year are usually not released until the third quarter. HSIS staff downloads these data and merges them into the prior-year file. This means that unlike 2001 and earlier HSIS files, the 2002 and later files contain AADT data for that year (e.g., all AADT data in the 2012 file have an AADT Year of 2012).
The original roadway inventory file was based on field inventory and constructions plans and was developed a number of years ago. Since that time, copies of all construction, resurfacing, or major widening plans are sent to the Inventory and Assessments unit who input data from the plans. Thus, the updating is done on an ongoing basis.
As noted above, the basic inventory file contains current characteristics of the state road system. It is estimated that there is approximately 92,000 miles of total roadway mileage in the state. There is 79,000 miles of roadway in the NC DOT roadway inventory system, approximately 14,000 of which are primary roadways. The 79,000 miles represents a very high proportion of total existing mileage in the state, much higher than is what is found in almost all of the states in the nation, since there are no “county roads” in North Carolina -- all such roads are controlled by the NC DOT. The remaining 15,000 miles of total state mileage are city streets.
As indicated above in the linkable-accidents discussion, the 2010 change in ownership of the NCDOT inventory and traffic volume files has resulted in new procedures for assigning AADT to roadway segments. This has resulted in changes to both (1) the amount of state-system mileage for which AADT estimates are made, and (2) inconsistencies between older and newer AADTs for some number of segments.
With respect to the first issue, prior to 2002, the HSIS system contains approximately 39,000 miles of crash-linkable roadway. Because of a sustained NCDOT effort to increase the number of miles to which crashes could be linked, the number of miles in the HSIS system increased to between 60,000 and 70,000 for 2002 – 2008. For 2009 and later, the number of total crash-linkable miles increased to approximately 78,000. All these miles are in the HSIS system. However, due to changes in the AADT assignment procedures beginning with the 2009 file, the number of linkable miles with AADT decreased to 27,000 in 2009 and 2010 and 43,000 in 2011 and later. This decrease results from the fact that very few AADT estimates are included for approximately 36,000 miles of rural and urban state-system roads classified as “local” in these 2009 and later files. NCDOT feels that many of the base counts for these local roads are so old that they are no longer usable in estimating AADTs. (Note that the NC roadway inventory file contains an “AADT Year” variable that can be examined by the user to determine when a segment-AADT was estimated.) Even though AADT is perhaps the most important variable in the HSIS inventory file, a decision was made to retain these older local-road AADTs in the pre-2009 HSIS files. However, the user must be aware that they are often based on (very) old raw count data. A decision was also made to retain the 2009 and later road segments without AADT for use by users who either do not need AADT or who wish to develop their own AADT estimates for the segments with missing AADT.
With respect to the consistency across time issue, the new procedures are considered to be much more accurate than past procedures for some unknown number of highway segments. Indeed, example manual comparisons of count station AADTs to AADTs assigned to nearby segments conducted by NCDOT and HSIS staffs show this to be the case. Unfortunately, there is no systematic way of determining which segments have consistent data across the pre- and post-2009 period. After discussions with NCDOT staff, it was decided that the original AADT values for all road segments classified above “local” in the 2002 – 2009 HSIS roadlog files would be replaced with revised values based on the updated procedures to the extent possible. (The 2002 file was the earliest that NCDOT traffic staff had updated data for.) This revision required that 2010 “AADT segment” addresses (i.e., county/route/mileposts for the begin and end of each AADT segment) be extrapolated back to the 2002 – 2009 HSIS inventory file segments. This is likely to have introduced some error in the estimates on routes where the “address” of a given segment has changed over time due to major reconstruction efforts (e.g., lengthening an upstream curve). However, both NCDOT and HSIS staff feels that any error introduced is likely much smaller than errors that would have been introduced by not revising the 2002-2008 AADTs. Note that neither the AADT values for road segments classified as “local” for 2002-2008 nor the 2001 and earlier AADT estimates for all road segments have not been revised and are not likely to be revised in the future.
The average homogeneous section length in the NC (and HSIS) roadway inventory file is approximately 0.7 miles. Table 1 presents mileage breakdowns for all paved two-way roadways (i.e., omitting all unpaved and one-way roadways) for the latest available year, 2012. Note that the rows for individual roadway categories show mileage with AADT estimates present. As expected since it is a state-controlled system, the file is predominately rural in nature, with close to 78% of the roadways with AADT estimates being in rural or near-rural areas. (NOTE: Of the total amount of mileposted mileage available for inclusion in the basic Inventory File, approximately 750 miles of roadway were omitted. These roadways are either characterized as couplets (i.e., usually urban roadways with the same route number in which the two directions of travel are separated by one or more city blocks) or as other divided roadway with "unbalanced" geometrics (i.e., roadway segments in which the geometrics, such as shoulder width or type, are not the same in both directions of travel). This relative small amount of mileage is difficult to work with both in terms of characterization of a "standard" cross-section and in terms of appropriate linkage with the accident files.)
| Roadway Category | Mileage |
|---|---|
| Urban freeways | 1,008.68 |
| Urban freeways < 4 Lanes | 8.438 |
| Urban multilane divided non-freeways | 1,510.16 |
| Urban multilane undivided non-freeways | 625.996 |
| Urban 2 In highways | 13,754.83 |
| Rural freeways | 977.619 |
| Rural freeways < 4 Ins | 8.376 |
| Rural multilane divided non-freeways | 1,070.51 |
| Rural multilane undivided non-freeways | 158.2 |
| Rural 2 In highways | 55,533.95 |
| Other | 4395.278 |
| Total | 79,052.04 |
The basic HSIS Inventory File contains both route description variables and cross-section variables that would be considered common among state inventory files. It includes such "standard" items as right and left shoulder width and type, lane widths, number of lanes, median width and type, roadway surface description, AADT, percent trucks, and others. In addition, it contains information on terrain, whether a section is a HPMS sample section, information on total truck percentages for certain roadway sections, and an indication of traffic growth factors for sections for which such growth factors have been developed.
While there is no construction zone inventory or project history file in North Carolina, each section of roadway in the basic inventory file contains an “improvement type” flag, which provides the general type of the most recent improvement implemented. This would differentiate between renovation, repaving, major rationing, minor rationing, and traffic safety/traffic engineering improvements. However, it does not provide the types of traffic safety/engineering improvement actually done. The improvement flag is based on construction plans and other sources identified above. Unfortunately, the companion variable related to the year of the last improvement was discontinued in 2009.
The major gaps in the inventory information include intersection/interchange inventory information, passing sight distance, design speed and design volume, information on inside shoulders on divided roadways (as discussed below) and, most importantly, information on either horizontal curve or vertical grade data. In addition, there is no current computerized intersection inventory information available. Inventory information does exist on a separate file related to traffic signals. At this point it is not readily mergeable with the location file
Examination of the single variable tables for key variables in the file indicates very little uncoded mileage for most of the variables -- less than 1.5%. The main problem variables are with the right and left "shoulder type" and "shoulder width," which are coded as "unknown" in over ten percent of the cases. Conversations with DOT staff indicated that this lack of inventory information involves both missing data and the inventory practices on divided roadways. On these divided roadways, "right shoulder" is indeed the outer shoulder on the right in the direction of inventory. However, in the base file, "left shoulder" actually refers to the outer shoulder on the far left side of the roadway, across the opposing lanes of travel. This is unlike other states where "left shoulder" on a divided roadway refers to inside, or median shoulder. Thus, for almost all of the divided roadways in North Carolina, there is no information on the inside, or median shoulder. There is information on median type and width, with the width being measured from the edge of the traveled lane, thus including the inside shoulder.
To determine the accuracy within the roadway file, both user and data maintaining groups within the North Carolina DOT were questioned, and a set of runs of variables that should be similar were compared to each other. Both the data maintenance and users staffs indicated that they felt the data in the universe file to be quite accurate. Field checks of the data in the HPMS samples have been done by the headquarters inventory staff, and indicate that the data accurately represented the cross sections of the roadway. As is the case for most states, the percent trucks assigned to each section are not as accurate as would be desired.
We also attempted to determine if there was consistency between variables for similar variables found in the Inventory File. In general, there was. For example, speed limit appeared to be consistent with functional class. Median type (including undivided) and median width were quite consistent in terms of miles in each category. There are two variables related to urban/rural location, with some differences indicated in the mileage that might be considered "rural" or "urban". One is "Population Group" (including "unincorporated"), and the second is "Urban/Rural Designated by Population”. “Population Group” variable indicates that about 93% of the roads fall within rural areas, whereas “Urban/Rural Designated Population” indicates about 89% of the roads fall within rural areas.
Conversations with the DOT staff indicated that each is based on slightly different definitions. "Population Group" is based solely on whether the road segment is inside an incorporated town or city, regardless of city size. The second variable, "Urban/Rural Designation by Population" is based on a combination of incorporation and urbanized area classifications. In short, the two define slightly different categories, and, according to the DOT staff, neither is considered to be a better measure of the overall nature of the roadway (i.e., design, roadside, nature of surrounding area, etc.). In general, the roadway inventory file contains a large amount of mileage when compared to other state systems, and the data in the file appear to be quite accurate.
Finally, there remain inconsistencies across time with the variables related to “Total Truck Percent” and “Percent Trucks at Peak.” The latter is uncoded for over 75% of the mileage for all years and is discontinued in 2009. The variable “Total Truck Percent” is uncoded for approximately 90% of the mileage for pre-2000 years, but is present for between 94% and 98% of the mileage for 2000-2011. It should be noted that the 2009-2011 percentages are still based on the older “legacy” estimates and not on the new method of estimating AADT which began in 2009. The 2012 truck percentage estimates are based on the newer method described in the Traffic Data section below, and are felt to be more accurate than the earlier legacy estimates.
As indicated above, significant improvements to the NC traffic data collection and AADT assignment efforts were made in 2010. The following describes the current program. The Traffic Survey Group of the NCDOT manages a Traffic Monitoring System (TMS) that generates AADT and truck percentage data used in the HSIS. The NCDOT GIS Unit publishes AADT data in the Road Characteristics file and the Traffic Survey Group publishes both AADT and truck data in an ESRI shape file. The TMS consists of a Continuous Count Program, a Coverage Count Program, and a Project Count Program. The Continuous Count Program involves the continuous 24-hour collection of volume, vehicle classification, and truck weight data at a sample of locations across the state. Continuous count sites are located on all types of highway facilities in all regions of the state. Approximately 70 Automatic Traffic Recording stations collect volume data (ATRs) and 44 legacy Weigh-In-Motion stations collected vehicle classification and truck weight data (WIMs). Continuous counts are screened for data quality and used to generate seasonal factors and statistics to support the Coverage and Project Count programs.
The Coverage Count Program involves the collection of short-term volume and vehicle classification counts to provide “coverage” of the major highway systems in North Carolina. Data are collected for 48 hours at each station at periodic intervals. There are approximately 48,000 volume-monitoring stations and 3,000 vehicle classification-monitoring stations. Using seasonal factors generated from the Continuous Count stations, the volume counts are factored to generate Annual Average Daily Traffic (AADT) estimates. This data are screened for consistency with historic trends at a station (temporal) and consistency between neighboring stations (spatial). Interstate mainline counts are collected every 5 to 8 interchanges and ramp counts are collected at all interchanges. Mainline interstate counts are factored to generate AADTs at these stations. AADT estimates on intervening segments are calculated by balancing the ramp volumes at interchanges between mainline count stations. Approximately 25,000 monitoring stations are updated annually including all interstate stations. All stations except interstates within major urban planning areas are updated biennially, half of the urban areas being updated each year. All primary route stations in rural areas are updated annually. Stations on rural secondary routes are updated biennially, approximately half of the stations each year. Stations not updated based on a new count during a reporting year have AADT estimated by applying growth factors to the previous count based AADT. Growth factors are calculated using count based AADT data only and are generated and applied by county or major urban area. This process generates a comprehensive volume coverage on all routes with a functional classification above Local. A partial coverage of Local routes is generated also. AADT data are used in Highway Performance Monitoring System (HPMS) reporting to FHWA, calculation of vehicle miles traveled (VMT), and support many processes within the NCDOT.
Vehicle classification counts are collected to provide a coverage of truck data for NC truck routes and National Highway System (NHS) routes. Vehicle classification counts are screened for data quality, seasonally factored to generate annual average volumes and percentages by vehicle class, and compared to historic values at the same station. This data are used to meet HPMS truck monitoring requirements, generate statewide average distributions, and are used for air quality modeling. Annualized truck volumes and percentages are generated for each count station. Vehicle classification coverage counts are updated on a three-year cycle.
The statistics generated from the data collected at the monitoring stations described above are applied to an extent of highway, called traffic segments. The minimum segmentation of the highway system for AADT traffic segments is related to the Functional Classification system (FC). For non-freeway routes, minimum segmentation is generated on a monitored route by the crossing routes with an FC above Local. When a segment is excessively long, or where land use causes high traffic variability along a segment, it will be subdivided into smaller traffic segments to provide a better representation of travel on the route. Freeway routes are segmented for AADT by their interchanges. Each segment extends from the center of an interchange to the center of the next interchange. Traffic segments on divided highways are generated for the inventory direction of the route only (this is defined by the GIS Unit). AADT reported on these segments are total travel for both directions. A volume monitoring station is maintained on each AADT traffic segment. The AADT data generated at the stations are reported on the AADT traffic segments. These segments are maintained and new segments added by the Traffic Survey Group when changes in the highway system are published by the GIS Unit. For monitoring stations located on Local FC, segments are not directly maintained. A segment reference is captured by performing a spatial join between the station points and the LRS arcs published by the GIS Unit. This method associates the AADT data with a portion of the route the AADT applies to but does not define where the extent of this AADT ends. For most segments captured using this technique, the actual extent of the AADT extends beyond the segment being reported.
With respect to truck traffic data, note that the updated truck percentages begin with the 2012 HSIS file rather than the 2009 file. Truck percentage data for 2009 - 2011 were still based on the legacy system, and would not be expected to be as accurate as the 2012 and later data. The 2012 and later vehicle classification data is collected to provide a coverage of truck data on NC truck routes and the NHS. No truck data are reported on routes that are not a truck or NHS route. There are 3,000 truck traffic segments across the state, each containing a vehicle classification monitoring station. For non-freeway routes, the minimum segmentation for truck traffic segments is related to the designated truck routes and NHS routes. Minimum segments are generated on a monitored non-freeway route where a truck route or NHS route intersects that route. Segmentation on freeway routes is generated using a two-step process. Major segments on a freeway are setup where other freeway routes intersect them. These segments are then subdivided where intersecting truck routes have higher truck volumes. Due to the high volume of trucks traveling on freeways, low volume truck routes have little effect on the volume of trucks on a freeway and additional segmentation is unnecessary.
In general, most truck traffic segments are comprised of multiple AADT segments. The annualized truck percentages generated from the vehicle class count data is assigned to each AADT segment that falls within a truck segment. Annual average truck volumes are then generated by applying the annualized truck percentages to the AADT data assigned to each AADT segment. This method ensures that truck travel estimates are synchronized with total travel estimates.
Finally, the Project Count Program within NCDOT provides traffic data collection services to support urban transportation modeling studies, traffic forecasting for TIP projects, and other transportation engineering studies. Services provided include the collection of daily, hourly, and vehicle classification counts using portable counters and turning movement and vehicle classification counts collected manually. Traffic counts are requested to provide more detailed traffic flows within a study area. A study will typically require a variety of data types collected at numerous locations. Counts are screened for data quality and consistency and are factored when requested. Approximately 1,400 portable counts and 400 manual counts are collected annually within the program. (It is noted that HSIS does not capture these counts, since there is no NC intersection inventory file. However, the counts could be used if such a file is developed in the future.)
As noted above, the accident data are subdivided into three subfiles -- accident, vehicle and occupant. These subfiles can be linked together using the "case number" variable, which includes the accident year (i.e., CASENO) present in each of the three files. When linking the occupant subfile, the additional linking variable "vehicle number" (i.e., VEHNO) must match so that the occupants are associated with the vehicle in which they were traveling. To link the Vehicle subfile with the Accident alone, first sort both subfiles by case number. To link the Occupant file with the other two subfiles, first sort both the Vehicle subfile and Occupant subfile by case number and vehicle position number. Next sort the Accident subfile by case number. Alternatively, the separate subfiles can be linked by specifying an SQL JOIN operation with the constraining condition that case number and vehicle number from each table are equal. SQL processing does not require the data to be pre-sorted and the output will not be in any particular sort order unless ORDER BY is specified. The Accident subfile can then be linked with the Roadway Inventory File using information related to county, route number, and milepost on the route. The actual linkage variables on the Accident file that are used in the merging operation are COUNTY, ROUTE and MILEPOST. To prepare the Accident subfile for linking with the Roadway Inventory File using a SAS data step process, the analyst must sort both the Accident and the Roadway File into location order (by COUNTY, ROUTE and MILEPOST on the Accident file and by COUNTY, RTE_NBR and BEGMP on the Roadway File). For the alternative SQL join, the analyst must specify an exact match on COUNTY, an exact match on ROUTE with RTE_NBR and a range match where MILEPOST occurs between BEGMP and ENDMP. (Programs to accomplish this merging and division are documented in the HSIS Programmer's Guidebook, available at FHWA.)
Finally, where appropriate and possible, a format, which defines categories within a given variable, has been developed for HSIS SAS variables. These categories are shown in the pages below. These formats have been saved in a format library, which can be provided to the user. As a naming convention, the "format name" is the same as the variable name; with the only exception being for certain character variables (in contrast with numeric variables). More specifically, a SAS format name has to be preceded by a "$" if the variable is character in nature. There is an 8-character length limit on both variable name and format name. In cases where the variable name is already eight characters in length, the addition of the preceding "$" would make the format name one character too long. In these cases, the format name is the same as the variable name except the final character of the variable name is dropped.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO |
|---|---|---|---|---|
| AADT | AVER ANNUAL DAILY TRAFFIC | Roadway | NUM (8) | 129 |
| AADT_YR | YEAR OF ADT | Roadway | CHAR (2) | 129 |
| ACC_DATE | ACCIDENT DATE-MMDDYY | Accident | NUM (8) | 31 |
| ACCESS | ACCESS CONTROL | Accident | NUM (8) | 31 |
| ACCESS | ACCESS CONTROL | Roadway | CHAR (1) | 130 |
| ACCTYPE | FIRST HARMFUL EVENT | Accident | NUM (8) | 31 |
| ACCYR | ACCIDENT YEAR | Accident | CHAR (4) | 32 |
| ACTION | DRIVER CHARGED WITH VIOL | Vehicle | CHAR (1) | 71 |
| ADD_DAMG | ADDITIONAL PROPERTY DAMAGE | Accident | NUM (8) | 33 |
| AGE | OCCUPANT AGE | Occupant | NUM (8) | 120 |
| AGENCY | INVESTIGATING AGENCY | Accident | CHAR (1) | 34 |
| AIR_SW | AIRBAG SWITCH STATUS | Occupant | NUM (8) | 121 |
| AIRBAGS | AIR BAGS PRESENT IN VEH | Vehicle | CHAR (1) | 71 |
| AIRDEPL | AIRBAGS DEPLOYED DURING CRASH | Vehicle | CHAR (1) | 72 |
| AIRDEPL | AIRBAG DEPLOYED | Occupant | NUM (8) | 121 |
| ALC_DRUG | ALCOHOL/DRUG IN ACC | Vehicle | NUM (8) | 72 |
| ALCFLAG | ALCOHOL/DRUGS IN ACC | Accident | CHAR (1) | 34 |
| ALCFLAG | ALCOHOL FLAG | Vehicle | CHAR (1) | 72 |
| AMB_TIME | TIME OF AMBULANCE REQUEST | Accident | CHAR (4) | 34 |
| AMBUL | AMBULANCE REQUESTED | Accident | CHAR (1) | 34 |
| AMTDAMG | AMOUNT OF DAMAGE TO VEH | Vehicle | NUM (8) | 73 |
| AREATYPE | AREA TYPE | Roadway | CHAR (1) | 130 |
| AXLE_NBR | COMMERCIAL CARRIER AXLES | Vehicle | NUM (8) | 73 |
| AXLES | NUMBER OF AXLES FOR TRL#1 | Vehicle | NUM (8) | 74 |
| AXLES2 | NUMBER OF AXLES FOR TRL#2 | Vehicle | NUM (8) | 74 |
| BEGMP | BEGIN MILEPOST | Roadway | NUM (8) | 130 |
| BIKEFLAG | BICYCLE IN ACC | Accident | CHAR (1) | 35 |
| BIKEFLAG | BICYCLE FLAG | Vehicle | CHAR (1) | 74 |
| BODY | CARGO BODY TYPE | Vehicle | NUM (8) | 74 |
| CASENO | YEAR + CASE NUMBER | Accident | NUM (8) | 35 |
| CASENO | NC ACCIDENT NUMBER WITH YR | Vehicle | NUM (8) | 75 |
| CASENO | NC ACCIDENT NUMBER WITH YR | Occupant | NUM (8) | 121 |
| CC_CITY | COMMERCIAL CARRIER CITY | Vehicle | CHAR (22) | 75 |
| CC_STATE | COMMERCIAL CARRIER STATE | Vehicle | CHAR (2) | 75 |
| CC_ZIP | COMMERCIAL CARRIER ZIP CODE | Vehicle | CHAR (9) | 75 |
| CCB_CITY | COMM CARR BUSINESS CITY | Vehicle | CHAR (2) | 75 |
| CCB_STAT | COMM CARR BUSINESS STATE | Vehicle | NUM (8) | 75 |
| CDL_IND | CDL INDICATOR | Vehicle | CHAR (1) | 76 |
| CITY | CITY/TOWN CODE (INCL CO) | Accident | NUM (8) | 35 |
| CNT_SEAT | NUMBER OF SEATS OCCUPIED | Vehicle | CHAR (1) | 76 |
| CNTR_PEAK_ | NUMBER OF LANES IN THE DIRECTION OPPOSITE TO THE PEAK HOUR DIRECTION FLOW | Roadway | NUM (8) | 130 |
| CNTY_RTE | COUNTY ROUTE NUMBER | Accident | CHAR (10) | 35 |
| CNTYRTE | COUNTY ROUTE NUMBER | Roadway | CHAR (10) | 131 |
| COMMFLAG | COMMERCIAL VEHICLE IN ACC | Accident | CHAR (1) | 35 |
| CONTRIB1 | VIOL/CONTRIBUT FACTOR #1 | Vehicle | NUM (8) | 76 |
| CONTRIB2 | VIOL/CONTRIBUT FACTOR #2 | Vehicle | NUM (8) | 76 |
| CONTRIB3 | VIOL/CONTRIBUT FACTOR #3 | Vehicle | NUM (8) | 76 |
| CONTRIB4 | VIOL/CONTRIBUT FACTOR #4 | Vehicle | NUM (8) | 76 |
| CONTRIB5 | VIOL/CONTRIBUT FACTOR #5 | Vehicle | NUM (8) | 76 |
| COUNTY | NC COUNTY NUMBER | Accident | NUM (8) | 36 |
| COUNTY | COUNTY | Roadway | CHAR (2) | 131 |
| CROSSMED | CROSS MEDIAN | Vehicle | CHAR (1) | 77 |
| DAMSEV | TAD#1 SEVERITY | Vehicle | CHAR (1) | 78 |
| DAMSEV2 | TAD#2 SEVERITY | Vehicle | CHAR (1) | 78 |
| DAMSEV3 | TAD#3 SEVERITY | Vehicle | CHAR (1) | 78 |
| DAY | DAY OF THE MONTH | Accident | CHAR (2) | 38 |
| DEPT_CDE | REPORTING DEPARTMENT CODE | Accident | CHAR (9) | 39 |
| DEVELOP | DEVELOPMENT AMOUNT | Accident | CHAR (8) | 39 |
| DHRVOL | DESIGN HOUR VOLUME | Roadway | CHAR (2) | 132 |
| DIR_TRVL | DIRECT OF TRAVEL ON | Vehicle | CHAR (2) | 78 |
| DIV | HIGHWAY DIVISION ROUTE | Roadway | CHAR (2) | 132 |
| DRG_RES | DRIVER ALC/DRUG TEST RESULT | Vehicle | CHAR (8) | 79 |
| DRG_SUSP | DRIVER ALC/DRUG SUSPECTED | Vehicle | CHAR (8) | 79 |
| DRSTATE | OUT OF STATE DRIVERS LIC | Vehicle | CHAR (1) | 79 |
| DRV_AGE | DRIVER/PEDEST AGE | Vehicle | CHAR (3) | 79 |
| DRV_BAC | DRIVER BLOOD ALCOHOL IN % | Vehicle | NUM (8) | 80 |
| DRV_CITY | DRIVER CITY | Vehicle | CHAR (1) | 80 |
| DRV_DOB | DRIVER DATE OF BIRTH | Vehicle | NUM (8) | 80 |
| DRV_INJ | DRIVER/PEDESTRIAN INJURY | Vehicle | CHAR (1) | 81 |
| DRV_LICENSE_RESTRICT | DRIVERS LICENSE RESTRICT | Vehicle | NUM (8) | 81 |
| DRV_RACE | DRIVER/PEDEST RACE | Vehicle | CHAR (1) | 82 |
| DRV_REST | DRIVER RESTRAINT USAGE | Vehicle | CHAR (2) | 82 |
| DRV_SEAT | DRIVER/PEDEST SEAT POS | Vehicle | CHAR (1) | 83 |
| DRV_SEX | DRIVER/PEDEST SEX | Vehicle | CHAR (1) | 83 |
| DRV_ZIP | DRIVER ZIP CODE | Vehicle | CHAR (9) | 83 |
| EJECT | EJECTION | Occupant | NUM (8) | 121 |
| EMERGUSE | EMERGENCY VEHICLE USE | Vehicle | NUM (8) | 83 |
| EMS_DES | EMERGENCY MEDICAL SERVICE | Occupant | NUM (50) | 122 |
| ENDMP | ENDING MILEPOST | Roadway | NUM (8) | 132 |
| EVENT1 | SEQUENCE OF EVENTS 1 | Vehicle | NUM (8) | 84 |
| EVENT2 | SEQUENCE OF EVENTS 2 | Vehicle | NUM (8) | 84 |
| EVENT3 | SEQUENCE OF EVENTS 3 | Vehicle | NUM (8) | 84 |
| EVENT4 | SEQUENCE OF EVENTS 4 | Vehicle | NUM (8) | 84 |
| EXPR_DT | LICENSE EXPIRATION DATE | Vehicle | NUM (8) | 86 |
| FIRE | POSTCRASH FIRE | Vehicle | NUM (8) | 86 |
| FRM_RD | FROM ROAD | Accident | CHAR (8) | 39 |
| FRMRD_CL | FROM ROAD CLASS | Accident | CHAR (4) | 39 |
| FROM_DIR | DIRECTION FROM FRM_RD | Accident | CHAR (2) | 40 |
| FUNC_CLS | FUNCTIONAL CLASS | Roadway | CHAR (2) | 133 |
| FUNC_ST | FUNCTIONAL CLASS (STATE) | Roadway | CHAR (1) | 133 |
| GOV_OWN | GOV OWNED VEH INDICATOR | Vehicle | CHAR (1) | 86 |
| GVWR_WGT | COMM CARR GROSS VEH WEIGHT | Vehicle | NUM (8) | 86 |
| HAZ_NUM1 | 1 DIGIT HAZMAT NUM PLACARD | Vehicle | NUM (8) | 86 |
| HAZ_NUM4 | 4 DIGIT HAZMAT NUM PLACARD | Vehicle | CHAR (4) | 87 |
| HAZ_PLAC | HAZMAT PLACARD INDICATOR | Vehicle | CHAR (1) | 87 |
| HAZFLAG | HAZMAT VEHICLE IN ACC | Accident | CHAR (1) | 40 |
| HAZMAT | HAZARDOUS CARGO | Vehicle | CHAR (1) | 87 |
| HITRUN | HIT AND RUN ACC | Accident | CHAR (1) | 40 |
| HOUR | HOUR | Accident | CHAR (4) | 41 |
| HOV_LN_CNT | NUMBER OF HOV LANES | Roadway | NUM (8) | 133 |
| HOV_TYD_CD | TYPE OF LANES USED FOR HOV EXCLUSIVELY OR DURING SPECIFIED TIME PERIODS | Roadway | NUM (8) | 133 |
| HPMS1 | HPMS SAMPLE ID | Roadway | NUM (8) | 133 |
| IMPACTFT | DIST TRAVEL AFTER IMPACT | Vehicle | NUM (8) | 87 |
| IMPACTSP | IMPACT SPEED | Vehicle | NUM (8) | 88 |
| IMPROVE1 | TYPE OF RECENT IMPROVEMENT | Roadway | CHAR (2) | 134 |
| INJ | OCCUPANT INJURY | Occupant | NUM (8) | 122 |
| INSURED | INSURANCE INDICATOR | Vehicle | CHAR (1) | 89 |
| INTOXC | DRIVER INTOXICATION GROUP | Vehicle | NUM (8) | 89 |
| INTSTMP | INTERSTATE MILEPOST | Roadway | CHAR (5) | 134 |
| INV_CNTL | INVENTORY CONTROL | Roadway | CHAR (1) | 135 |
| L_PERMIT | LEARNER PERMIT | Vehicle | CHAR (1) | 89 |
| LENGTRL | LENGTH OF TRAILER #1,IN FT | Vehicle | NUM (8) | 89 |
| LENGTRL2 | LENGTH OF TRAILER #2,IN FT | Vehicle | NUM (8) | 89 |
| LIC_IND | DRIVER LICENSE INDICATOR | Vehicle | CHAR (1) | 90 |
| LIC_STAT | LICENSE STATE | Vehicle | CHAR (2) | 90 |
| LICRESTR | RESTRICT ON DRIV LICENSE | Vehicle | CHAR (2) | 90 |
| LICTYPE | TYPE OF DRIVERS LICENSE | Vehicle | CHAR (1) | 91 |
| LIGHT | LIGHT CONDITION | Accident | NUM (8) | 42 |
| LISTCNTL | LIST CONTROL | Roadway | CHAR (1) | 135 |
| LOC_TYPE | ACCIDENT LOCATION TYPE | Accident | NUM (8) | 42 |
| LOCALITY | DEVELOPMENT TYPE | Accident | NUM (8) | 43 |
| LSHL_TYP | LEFT SHOULDER TYPE | Roadway | CHAR (2) | 136 |
| LSHLDWID | LEFT SHOULDER WIDTH | Roadway | NUM (8) | 137 |
| LT_PARK | LEFT PEAK PARK | Roadway | CHAR (1) | 137 |
| MAKE | VEHICLE MAKE | Vehicle | CHAR (2) | 91 |
| MAKENAME | VEHICLE MAKE NAME | Vehicle | CHAR (20) | 91 |
| MANEUVER | VEH MANEUVER/PEDEST ACTION | Vehicle | NUM (8) | 92 |
| MCFLAG | MOTORCYCLE IN ACC | Accident | CHAR (1) | 44 |
| MEANS | MEANS OF INVOLVEMENT | Accident | CHAR | 44 |
| MED_TYPE | MEDIAN TYPE | Roadway | CHAR (1) | 137 |
| MEDWID | MEDIAN WIDTH TOTAL | Roadway | NUM (8) | 138 |
| MHARM_AC | MOST HARMFUL EVENT | Accident | NUM (8) | 45 |
| MILEPOST | MILEPOST | Accident | NUM (8) | 45 |
| MISCACT1 | MISCELLANEOUS ACTION | Vehicle | CHAR (2) | 93 |
| MONTH | MONTH OF ACCIDENT | Accident | CHAR (2) | 46 |
| MOPEDFLG | MOPED IN ACCIDENT | Accident | CHAR (1) | 46 |
| MOSTHARM | MOST HARMFUL EVENT | Vehicle | NUM (8) | 94 |
| MUNI_DIR | DIRECTION FROM MUNICIPALITY TO ACC | Accident | CHAR (2) | 47 |
| MUNI_DIS | DISTANCE FROM MUNICIPALITY IN MILES | Accident | NUM (8) | 47 |
| MVMT | MILLION VEHICLE MILLIONS OF TRAVEL | Accident | NUM (8) | 47 |
| MVMT | MILLION VEHICLE MILES TRAVELLED | Roadway | NUM (8) | 138 |
| NBR_LANE | NUMBER OF LANES | Accident | NUM (8) | 48 |
| NEARTOWN | IN OR NEAR TOWN | Accident | NUM (8) | 48 |
| NHS | NATIONAL HIGHWAY SYSTEM | Roadway | CHAR (1) | 138 |
| NO_LANES | NUMBER OF LANES- TOTAL | Roadway | CHAR (1) | 139 |
| NON_REP | NON-REPORTABLE | Accident | NUM (8) | 48 |
| NONMTCNT | NON-MOTORIST COUNT | Accident | NUM (8) | 49 |
| NUM_A | TOTAL A INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_B | TOTAL B INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_C | TOTAL C INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_K | TOTAL KILLED IN VEHICLE | Vehicle | CHAR (2) | 96 |
| NUM_OCCS | TOTAL OCCUPANTS IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_POCS | NO OF POINTS OF CONTACT | Vehicle | CHAR (1) | 96 |
| NUM_TADS | NUMBER OF TAD CODES | Vehicle | CHAR (1) | 96 |
| NUM_UNIT | NUMBER OF UNITS | Accident | NUM (8) | 49 |
| NUMINJ | TOT INJURED IN VEH (K+A+B+C) | Vehicle | CHAR (2) | 96 |
| NUMVEHS | NUMBER OF VEH+PED+BIKE | Accident | NUM (8) | 49 |
| NUMVIOLS | NUM OF VIOLS INDICATED | Vehicle | CHAR (1) | 97 |
| OBJECT1 | TYPE OF OBJECT STRUCK | Vehicle | CHAR (2) | 97 |
| OFFCR_ST | REPORTING OFFICER STATE | Accident | CHAR (2) | 49 |
| ON_RD | ON ROAD | Accident | CHAR (8) | 49 |
| ON_RD | ON ROAD | Vehicle | CHAR (8) | 98 |
| ONEWAY_DIR | ONE WAY DIRECTION | Roadway | NUM (8) | 139 |
| ONRD_CL | ON ROAD CLASS | Accident | CHAR (4) | 50 |
| ONRD_CL | ON ROAD CLASS | Vehicle | CHAR (4) | 99 |
| OTH_UNIT | OTHER UNIT TYPE | Vehicle | CHAR (20) | 99 |
| OUTSTATE | OUT OF STATE VEH REGIS | Vehicle | CHAR (1) | 99 |
| OWN_CITY | VEHICLE OWNER CITY | Vehicle | CHAR (22) | 99 |
| OWN_STAT | VEHICLE OWNER STATE | Vehicle | CHAR (2) | 100 |
| OWN_ZIP | VEHICLE OWNER ZIP CODE | Vehicle | CHAR (9) | 100 |
| OWNERTYP | OWNER CATEGORY | Vehicle | CHAR (3) | 100 |
| PARK_VEH | INDICATOR OF PARKED VEH | Vehicle | CHAR (1) | 100 |
| PATROLAC | PATROL AREA CODE | Accident | CHAR (2) | 50 |
| PAVECOND | PAVEMENT CONDITION | Roadway | CHAR (2) | 139 |
| PAVED_LSHLDWID | PAVED SHOULD WIDTH (LEFT) | Roadway | NUM (8) | 139 |
| PAVED_RSHLDWID | PAVED SHOULD WIDTH (RIGHT) | Roadway | NUM (8) | 139 |
| PCT_TRK1 | PERCENT TRUCKS | Roadway | CHAR (2) | 140 |
| PEAK_TRK | PERCENT TRUCKS AT PEAK | Roadway | CHAR (1) | 140 |
| PEAKLANE | NUMBER OF LANES IN THE PEAK HOUR DIRECTION OF FLOW | Roadway | NUM (8) | 141 |
| PED_LOC | NON-MOTORIST LOCATION | Vehicle | NUM (8) | 101 |
| PEDACT | NON-MOTORIST ACTION | Vehicle | NUM (8) | 102 |
| PEDCONT1 | CONTRIB CIRCUM NON-MOT 1 | Vehicle | NUM (8) | 103 |
| PEDCONT2 | CONTRIB CIRCUM NON-MOT 2 | Vehicle | NUM (8) | 103 |
| PEDFLAG | PEDESTRIAN IN ACC | Accident | CHAR (1) | 50 |
| PEDFLAG | PEDESTRIAN IN ACCIDENT | Vehicle | CHAR (1) | 103 |
| PEDHITBY | PUPIL PEDEST STRUCK BY (SCHLBUS CRASH) | Vehicle | CHAR (1) | 104 |
| PHYSCOND | PHYSICAL COND OF DRIVER | Vehicle | NUM (8) | 104 |
| PLOTQUAL | QUALITY OF MILEPOST | Accident | CHAR (1) | 51 |
| POP_GRP | CITY POPULATION IN 1000 | Accident | NUM (8) | 51 |
| POP_GRP | POPULATION GROUP | Roadway | CHAR (1) | 141 |
| PROPDAM | TOTAL PROPERTY DAMAGE | Accident | NUM (8) | 52 |
| PRSN_CTY | PERSON COUNTY | Occupant | CHAR (22) | 122 |
| PRSN_DOB | PERSON DATE OF BIRTH | Occupant | NUM (8) | 122 |
| PRSN_NBR | PERSON NUMBER | Occupant | NUM (8) | 122 |
| PRSN_ST | PERSON STATE | Occupant | CHAR (2) | 123 |
| PRSN_TYP | PERSON TYPE | Occupant | NUM (8) | 123 |
| PRSN_ZIP | PERSON ZIP CODE | Occupant | CHAR (9) | 123 |
| PSTD_RTE_C | POSTED ROUTES | Roadway | CHAR (7) | 141 |
| PTCONT1 | POINT OF CONTACT #1 | Vehicle | CHAR (2) | 105 |
| PTCONT2 | POINT OF CONTACT #2 | Vehicle | CHAR (2) | 105 |
| PTCONT3 | POINT OF CONTACT #3 | Vehicle | CHAR (2) | 105 |
| PTCONT4 | POINT OF CONTACT #4 | Vehicle | CHAR (2) | 105 |
| PTCONT5 | POINT OF CONTACT #5 | Vehicle | CHAR (2) | 105 |
| PTCSTAT | PORTABLE TRAFFIC COUNTER | Roadway | CHAR (8) | 142 |
| PVA | PUBLIC VEHICLE AREA | Accident | CHAR (2) | 52 |
| RACE | OCCUPANT RACE | Occupant | NUM (8) | 123 |
| RD_CHAR1 | ROAD CHARACTER | Accident | NUM (8) | 53 |
| RD_CONF | ROAD CONFIGURATION | Accident | NUM (8) | 53 |
| RD_PAVE | TYPE OF ROAD SURFACE (REP) | Accident | NUM (8) | 54 |
| RD2OBJST | DISTANCE TO OBJECT STRUCK | Vehicle | NUM (8) | 106 |
| RDSURF | SURFACE CONDITION | Accident | NUM (8) | 54 |
| RECCONTCD | RECORD CONTINUATION CODE | Roadway | CHAR (1) | 142 |
| REFDISFT | DIST FROM FRM_RD IN FEET | Accident | NUM (8) | 54 |
| REFDISMI | DIST FROM FRM_RD IN MILES | Accident | NUM (8) | 55 |
| REGION | REGION OF IMPACT | Vehicle | CHAR (1) | 107 |
| REL_RD | RELATION TO ROADWAY | Accident | NUM (8) | 55 |
| REPORT | REPORTABLE STATUS | Accident | CHAR (1) | 55 |
| REST1 | OCCUPANT RESTRAINT | Occupant | NUM (8) | 124 |
| RMP_SVRD | RAMP OR SERVICE ROAD | Accident | NUM (8) | 56 |
| ROAD_CLS | ROAD CLASSIFICATION | Accident | NUM (8) | 56 |
| ROADCNT1 | ROADWAY CONTRIBUT CIRCUM 1 | Accident | NUM (8) | 57 |
| ROADCNT2 | ROADWAY CONTRIBUT CIRCUM 2 | Accident | NUM (8) | 57 |
| RODWYCLS | ROAD WAY CLASS | Accident | CHAR (2) | 57 |
| RODWYCLS | ROAD WAY CLASS VARIABLE | Roadway | CHAR (2) | 142 |
| ROLLOVER | VEHICLE ROLLOVER | Vehicle | CHAR (1) | 107 |
| ROLLPTCT | ROLLOVER, POINT OF CONTACT | Vehicle | NUM (8) | 107 |
| ROLLTAD | ROLLOVER, TAD SEVERITY | Vehicle | NUM (8) | 108 |
| ROUGH | PAVEMENT ROUGHNESS | Roadway | CHAR (3) | 142 |
| ROW | RIGHT OF WAY | Roadway | CHAR (2) | 143 |
| RRX_NUM | RAIL ROAD CROSSING NUMBER | Accident | CHAR (7) | 58 |
| RRXFLAG | RAILROAD CROSS NOT INDICATED | Accident | CHAR (1) | 58 |
| RSHL_TYP | RIGHT SHOULDER TYPE | Roadway | CHAR (2) | 143 |
| RSHLDWID | RIGHT SHOULDER WIDTH | Roadway | NUM (8) | 144 |
| RT_PARK | RIGHT PEAK PARK | Roadway | CHAR (1) | 144 |
| RTE_NBR | MILEPOSTED ROUTE | Accident | CHAR (8) | 58 |
| RTE_NBR | ROUTE INVENTORIED | Roadway | CHAR (8) | 144 |
| RTE_TYPE | ROUTE TYPE (1ST DIGIT OF RTE_NBR) | Roadway | CHAR (1) | 145 |
| RULURBID | RURAL URBAN IDENTIFICATION | Roadway | CHAR (2) | 145 |
| RURURB | RURAL-URBAN IDENTIFICATION | Accident | CHAR (1) | 58 |
| SCENIC | SCENIC BYWAY | Roadway | CHAR (1) | 145 |
| SCH_BUS1 | SCHOOL BUS CONTACT VEH | Vehicle | NUM (8) | 108 |
| SCH_BUS2 | SCHOOL BUS NON-CONTACT VEH | Vehicle | NUM (8) | 108 |
| SCHBUS | SCHOOL BUS INVOLVED IN ACC | Accident | CHAR (1) | 58 |
| SEATPOS | SEATING POSITION | Occupant | NUM (8) | 124 |
| SEG_LNG | SECTION LENGTH IN MILES | Roadway | NUM (8) | 145 |
| SEVERITY | WORST INJURY IN ACC | Accident | CHAR (1) | 59 |
| SEX | OCCUPANT SEX | Occupant | NUM (8) | 125 |
| SIGHTDIS | SIGHT DISTANCE | Roadway | CHAR (2) | 145 |
| SOB_TEST | CHEMICAL TEST GIVEN | Vehicle | NUM (8) | 109 |
| SPD_GRP | COMPUTED SPEED OF ACCIDENT | Accident | CHAR (1) | 59 |
| SPD_LIMT | SPEED LIMIT | Roadway | CHAR (2) | 145 |
| SPDLIM | POSTED SPEED LIMIT | Vehicle | NUM (8) | 109 |
| SPEC_SYS | SPECIAL SYSTEM | Roadway | CHAR (1) | 146 |
| SPILL | HAZARDOUS CARGO SPILL | Vehicle | CHAR (1) | 110 |
| STATE_SY | STATE HIGHWAY SYSTEM | Roadway | CHAR (1) | 147 |
| STRCTR_CD | LOCATION OF BRIDGES, TUNNEL AND CAUSEWAYS | Roadway | NUM (8) | 147 |
| STREET_NAM | STREET NAME | Roadway | NUM (20) | 148 |
| SURF_TYP | SURFACE TYPE | Roadway | CHAR (2) | 148 |
| SURF_WID | SURFACE WIDTH TOTAL | Roadway | NUM (8) | 148 |
| TERRAIN | TERRAIN | Roadway | CHAR (1) | 148 |
| TICKET1 | CITATION ISSUED TO SOMEONE IN ACCIDENT | Accident | CHAR (1) | 59 |
| TIME | TIME OF DAY (24 HOUR) | Accident | CHAR (4) | 60 |
| TIRESKID | TIRE IMPRESSIONS IN FEET | Vehicle | NUM (8) | 110 |
| TO_DIR | DIRECTION TOWARD | Accident | CHAR (2) | 61 |
| TO_RD | TOWARD ROAD | Accident | CHAR (8) | 61 |
| TOLL_DIRECTION | TOLL CHARGED | Roadway | CHAR (7) | 149 |
| TORD_CL | TOWARD ROAD CLASS | Accident | CHAR (4) | 61 |
| TOT_KILL | TOTAL KILLED IN ACC | Accident | NUM (8) | 62 |
| TOTAINJ | TOTAL A INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOTBINJ | TOTAL B INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOTCINJ | TOTAL C INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOTLENG | TOT LENGTH OF TRAILER(S) IN FEET | Vehicle | CHAR (3) | 110 |
| TOWAWAY | VEHICLE DRIVEABLE | Vehicle | NUM (8) | 111 |
| TOWED_BY | TOWED BY | Vehicle | CHAR (50) | 111 |
| TOWED_TO | TOWED TO | Vehicle | CHAR (50) | 111 |
| TOWN | TOWN | Roadway | CHAR (2) | 149 |
| TOWN_CD | DOT ASSIGNED TOWN CODE | Accident | NUM (8) | 62 |
| TRAPPED | TRAPPED | Occupant | NUM (8) | 125 |
| TRF_CNTL | TRAFFIC CONTROL TYPE | Accident | NUM (8) | 63 |
| TRF_OPER | TRAFFIC CONTROL OPERATING | Accident | NUM (8) | 63 |
| TRF_VIS | TRAFFIC CONTROL VISIBLE | Accident | CHAR (8) | 63 |
| TRFGROW | TRAFFIC GROWTH FACTOR | Roadway | NUM (8) | 149 |
| TRK_RTE | DESIGNATED TRUCK ROUTE | Roadway | CHAR (1) | 149 |
| TRL_TYPE | TRAILER TYPE | Vehicle | NUM (8) | 111 |
| TRL1_FLG | DATA PRESENT (TRAILER #1) | Vehicle | CHAR (1) | 112 |
| TRL2_FLG | DATA PRESENT (TRAILER #2) | Vehicle | CHAR (1) | 112 |
| TRNLNWD | TURN LANE WIDTH | Roadway | NUM (8) | 149 |
| TRT_FAC | TREATMENT FACILITY NAME | Occupant | CHAR (100) | 125 |
| TRVL_SPD | ESTIMATED ORIGINAL SPEED | Vehicle | NUM (8) | 112 |
| UNDEROVR | VEHICLE UNDERRIDE/OVERRIDE | Vehicle | NUM (8) | 113 |
| UNIT_TYP | UNIT TYPE | Vehicle | CHAR (1) | 113 |
| UPDATE_ | UPDATE | Roadway | NUM (8) | 150 |
| URB_LOC | URBAN LOCATION | Roadway | CHAR (1) | 150 |
| URB_POP | RUR/URB DESIGNATED BY POP | Roadway | CHAR (1) | 150 |
| V_DAMAG2 | TAD#2 LOCATION | Vehicle | CHAR (2) | 114 |
| V_DAMAG3 | TAD#3 LOCATION | Vehicle | CHAR (2) | 114 |
| V_DAMAGE | TAD#1 (AREA OF DAMAGE) LOC | Vehicle | CHAR (2) | 114 |
| VEH_SEIZ | VEHICLE SEIZURE DWI | Vehicle | CHAR (1) | 114 |
| VEH_DEF | VEHICLE DEFECT | Vehicle | NUM (8) | 115 |
| VEHNO | VEHICLE POSITION NUMBER | Vehicle | NUM (8) | 115 |
| VEHNO | VEHICLE POSITION NUMBER | Occupant | NUM (8) | 125 |
| VEHON | VEHICLE LOCATION BASED ON ROAD | Vehicle | CHAR (1) | 115 |
| VEHSEV | SEVERITY | Vehicle | NUM (8) | 115 |
| VEHTYPE | VEHICLE TYPE | Vehicle | NUM (8) | 116 |
| VEHYR | MODEL YEAR OF VEHICLE | Vehicle | NUM (8) | 117 |
| VIN | VEHICLE IDENTIFICATION NO | Vehicle | CHAR (17) | 117 |
| VIN_ID | VEHICLE IDENTIFICATION NO | Vehicle | CHAR (25) | 117 |
| VISION | VISION OBSTRUCTION | Vehicle | NUM (8) | 118 |
| WEATHER1 | WEATHER CONDITION 1 | Accident | NUM (8) | 64 |
| WEATHER2 | WEATHER CONDITION 2 | Accident | NUM (8) | 64 |
| WEEKDAY | DAY OF WEEK | Accident | CHAR | 64 |
| WETHCONT | WEATHER CONTRIBUT TO ACC | Accident | NUM (8) | 64 |
| WIDTRL | WIDTH OF TRAILER #1 (IN) | Vehicle | NUM (8) | 118 |
| WIDTRL2 | WIDTH OF TRAILER #2 (IN) | Vehicle | NUM (8) | 118 |
| WORKZONE | WORK ZONE MARKED | Accident | NUM (8) | 65 |
| WTDSGSPD | WEIGHTED DESIGN SPEED | Roadway | CHAR (2) | 150 |
| WZ_ACT | WORK ZONE ACTIVITY | Accident | NUM (8) | 65 |
| WZ_AREA | WORK ZONE AREA | Accident | NUM (8) | 65 |
| WZ_LOC | WORK ZONE CRASH LOCATION | Accident | NUM (8) | 65 |
| Y_LINE | NON-MILEPOSTED CROSSING ROUTE LOCATION | Accident | CHAR (1) | 66 |
| YEAR | YEAR OF TRAFFIC COUNT | Roadway | NUM (8) | 151 |
| YR_IMPR1 | YEAR OF RECENT IMPROVEMENT | Roadway | CHAR (2) | 151 |
| YRADD | YEAR ADDED | Roadway | CHAR (2) | 151 |
| ZIP_ADR | REPORTING OFFICER ZIP CODE | Accident | CHAR (9) | 66 |
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO |
|---|---|---|---|---|
| ACC_DATE | ACCIDENT DATE-MMDDYY | Accident | NUM (8) | 31 |
| ACCESS | ACCESS CONTROL | Accident | NUM (8) | 31 |
| ACCTYPE | FIRST HARMFUL EVENT | Accident | NUM (8) | 31 |
| ACCYR | ACCIDENT YEAR | Accident | CHAR (4) | 32 |
| ADD_DAMG | ADDITIONAL PROPERTY DAMAGE | Accident | NUM (8) | 33 |
| AGENCY | INVESTIGATING AGENCY | Accident | CHAR (1) | 34 |
| ALCFLAG | ALCOHOL/DRUGS IN ACC | Accident | CHAR (1) | 34 |
| AMB_TIME | TIME OF AMBULANCE REQUEST | Accident | CHAR (4) | 34 |
| AMBUL | AMBULANCE REQUESTED | Accident | CHAR (1) | 34 |
| BIKEFLAG | BICYCLE IN ACC | Accident | CHAR (1) | 35 |
| CASENO | YEAR + CASE NUMBER | Accident | NUM (8) | 35 |
| CITY | CITY/TOWN CODE (INCL CO) | Accident | NUM (8) | 35 |
| CNTY_RTE | COUNTY ROUTE NUMBER | Accident | CHAR (10) | 35 |
| COMMFLAG | COMMERCIAL VEHICLE IN ACC | Accident | CHAR (1) | 35 |
| COUNTY | NC COUNTY NUMBER | Accident | NUM (8) | 36 |
| DAY | DAY OF THE MONTH | Accident | CHAR (2) | 38 |
| DEPT_CDE | REPORTING DEPARTMENT CODE | Accident | CHAR (9) | 39 |
| DEVELOP | DEVELOPMENT AMOUNT | Accident | CHAR (8) | 39 |
| FRM_RD | FROM ROAD | Accident | CHAR (8) | 39 |
| FRMRD_CL | FROM ROAD CLASS | Accident | CHAR (4) | 39 |
| FROM_DIR | DIRECTION FROM FRM_RD | Accident | CHAR (2) | 40 |
| HAZFLAG | HAZMAT VEHICLE IN ACC | Accident | CHAR (1) | 40 |
| HITRUN | HIT AND RUN ACC | Accident | CHAR (1) | 40 |
| HOUR | HOUR | Accident | CHAR (4) | 41 |
| LIGHT | LIGHT CONDITION | Accident | NUM (8) | 42 |
| LOC_TYPE | ACCIDENT LOCATION TYPE | Accident | NUM (8) | 42 |
| LOCALITY | DEVELOPMENT TYPE | Accident | NUM (8) | 43 |
| MCFLAG | MOTORCYCLE IN ACC | Accident | CHAR (1) | 44 |
| MEANS | MEANS OF INVOLVEMENT | Accident | CHAR | 44 |
| MHARM_AC | MOST HARMFUL EVENT | Accident | NUM (8) | 45 |
| MILEPOST | MILEPOST | Accident | NUM (8) | 45 |
| MONTH | MONTH OF ACCIDENT | Accident | CHAR (2) | 46 |
| MOPEDFLG | MOPED IN ACCIDENT | Accident | CHAR (1) | 46 |
| MUNI_DIR | DIRECTION FROM MUNICIPALITY TO ACC | Accident | CHAR (2) | 47 |
| MUNI_DIS | DISTANCE FROM MUNICIPALITY IN MILES | Accident | NUM (8) | 47 |
| MVMT | MILLION VEHICLE MILLIONS OF TRAVEL | Accident | NUM (8) | 47 |
| NBR_LANE | NUMBER OF LANES | Accident | NUM (8) | 48 |
| NEARTOWN | IN OR NEAR TOWN | Accident | NUM (8) | 48 |
| NON_REP | NON-REPORTABLE | Accident | NUM (8) | 48 |
| NONMTCNT | NON-MOTORIST COUNT | Accident | NUM (8) | 49 |
| NUM_UNIT | NUMBER OF UNITS | Accident | NUM (8) | 49 |
| NUMVEHS | NUMBER OF VEH+PED+BIKE | Accident | NUM (8) | 49 |
| OFFCR_ST | REPORTING OFFICER STATE | Accident | CHAR (2) | 49 |
| ON_RD | ON ROAD | Accident | CHAR (8) | 49 |
| ONRD_CL | ON ROAD CLASS | Accident | CHAR (4) | 50 |
| PATROLAC | PATROL AREA CODE | Accident | CHAR (2) | 50 |
| PEDFLAG | PEDESTRIAN IN ACC | Accident | CHAR (1) | 50 |
| PLOTQUAL | QUALITY OF MILEPOST | Accident | CHAR (1) | 51 |
| POP_GRP | CITY POPULATION IN 1000 | Accident | NUM (8) | 51 |
| PROPDAM | TOTAL PROPERTY DAMAGE | Accident | NUM (8) | 52 |
| PVA | PUBLIC VEHICLE AREA | Accident | CHAR (2) | 52 |
| RD_CHAR1 | ROAD CHARACTER | Accident | NUM (8) | 53 |
| RD_CONF | ROAD CONFIGURATION | Accident | NUM (8) | 53 |
| RD_PAVE | TYPE OF ROAD SURFACE (REP) | Accident | NUM (8) | 54 |
| RDSURF | SURFACE CONDITION | Accident | NUM (8) | 54 |
| REFDISFT | DIST FROM FRM_RD IN FEET | Accident | NUM (8) | 54 |
| REFDISMI | DIST FROM FRM_RD IN MILES | Accident | NUM (8) | 55 |
| REL_RD | RELATION TO ROADWAY | Accident | NUM (8) | 55 |
| REPORT | REPORTABLE STATUS | Accident | CHAR (1) | 55 |
| RMP_SVRD | RAMP OR SERVICE ROAD | Accident | NUM (8) | 56 |
| ROAD_CLS | ROAD CLASSIFICATION | Accident | NUM (8) | 56 |
| ROADCNT1 | ROADWAY CONTRIBUT CIRCUM 1 | Accident | NUM (8) | 57 |
| ROADCNT2 | ROADWAY CONTRIBUT CIRCUM 2 | Accident | NUM (8) | 57 |
| RODWYCLS | ROAD WAY CLASS | Accident | CHAR (2) | 57 |
| RRX_NUM | RAIL ROAD CROSSING NUMBER | Accident | CHAR (7) | 58 |
| RRXFLAG | RAILROAD CROSS NOT INDICATED | Accident | CHAR (1) | 58 |
| RTE_NBR | MILEPOSTED ROUTE | Accident | CHAR (8) | 58 |
| RURURB | RURAL-URBAN IDENTIFICATION | Accident | CHAR (1) | 58 |
| SCHBUS | SCHOOL BUS INVOLVED IN ACC | Accident | CHAR (1) | 58 |
| SEVERITY | WORST INJURY IN ACC | Accident | CHAR (1) | 59 |
| SPD_GRP | COMPUTED SPEED OF ACCIDENT | Accident | CHAR (1) | 59 |
| TICKET1 | CITATION ISSUED TO SOMEONE IN ACCIDENT | Accident | CHAR (1) | 59 |
| TIME | TIME OF DAY (24 HOUR) | Accident | CHAR (4) | 60 |
| TO_DIR | DIRECTION TOWARD | Accident | CHAR (2) | 61 |
| TO_RD | TOWARD ROAD | Accident | CHAR (8) | 61 |
| TORD_CL | TOWARD ROAD CLASS | Accident | CHAR (4) | 61 |
| TOT_KILL | TOTAL KILLED IN ACC | Accident | NUM (8) | 62 |
| TOTAINJ | TOTAL A INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOTBINJ | TOTAL B INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOTCINJ | TOTAL C INJURIES IN ACC | Accident | NUM (8) | 62 |
| TOWN_CD | DOT ASSIGNED TOWN CODE | Accident | NUM (8) | 62 |
| TRF_CNTL | TRAFFIC CONTROL TYPE | Accident | NUM (8) | 63 |
| TRF_OPER | TRAFFIC CONTROL OPERATING | Accident | NUM (8) | 63 |
| TRF_VIS | TRAFFIC CONTROL VISIBLE | Accident | CHAR (8) | 63 |
| WEATHER1 | WEATHER CONDITION 1 | Accident | NUM (8) | 64 |
| WEATHER2 | WEATHER CONDITION 2 | Accident | NUM (8) | 64 |
| WEEKDAY | DAY OF WEEK | Accident | CHAR | 64 |
| WETHCONT | WEATHER CONTRIBUT TO ACC | Accident | NUM (8) | 64 |
| WORKZONE | WORK ZONE MARKED | Accident | NUM (8) | 65 |
| WZ_ACT | WORK ZONE ACTIVITY | Accident | NUM (8) | 65 |
| WZ_AREA | WORK ZONE AREA | Accident | NUM (8) | 65 |
| WZ_LOC | WORK ZONE CRASH LOCATION | Accident | NUM (8) | 65 |
| Y_LINE | NON-MILEPOSTED CROSSING ROUTE LOCATION | Accident | CHAR (1) | 66 |
| ZIP_ADR | REPORTING OFFICER ZIP CODE | Accident | CHAR (9) | 66 |
Definition: Date when the accident occurred.
Additional Information: Element has YYYYMMDD format up to 1999, where YYYY = Year, MM = Month and DD = Day. From 2000 onwards the element captures the time of the accident as well.
Definition: Access control at the location of the crash.
Additional Information: New element added in 2000.
Definition: First harmful event in the crash sequence.
Additional Information:
1. Some changes in codes for this element from 2000 onwards. This resulted in some shifts in categories. Some categories were combined, while some categories were differentiated because of this.
2. There is a significant decrease in run-off road crashes from 1999-2000. This is because quite a few crashes that were coded as run-off road until 1999 were coded as fixed object crashes from 2000 onwards. Similarly, category 18 (movable object) for 2000 and later years appears to be similar to category 34 (other object) for 1999 and earlier years. Also, categories 28 and 29 (sideswipe crashes) for 1999 and earlier years. Also categories 28 and 29 (sideswipe crashes) for 2000 and later years appear to be similar to category 36 for 1999 and earlier years.
* Categories discontinued from 2000 onwards.
** Categories added from 2000 onwards.
Definition: Year when the accident occurred.
Additional Information: Format YYYY where YYYY = Year. Element discontinued from 2000 onwards.
Definition: Additional property damage as a result of the crash.
Additional Information: Element discontinued from 2000 onwards.
Definition: Agency that investigated the crash.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether or not alcohol or drugs were involved when the accident occurred.
Additional Information: ‘0’ for Pre 2000. ‘1’ for Pre 2000.
Definition: Time when ambulance was requested to respond to the accident.
Additional Information: Element discontinued from 2000 onwards
Definition: Whether or not an ambulance was requested.
Additional Information: Element discontinued from 2000 onwards.
Definition: Bicycle in Accident
Additional Information: ‘0’ for Pre 2000. ‘1’ for Pre 2000.
Definition: Year and Case Number
Additional Information: Format YYNNNNNN where YY = Year and NNNNN = Case Number. Element type is CHAR for 1990 to 1999.
Definition: City/Town Code (Include CO)
Additional Information: For data before 2010, City/Town Code has to be combined with DIV (i.e. Highway Division Route) variable to get 4-digit City/Town codes. Contact HSIS staff for more information on codes for the city element. Also note that city element codes are different for pre 2000 and post 2000 years. HSIS staff maintains a list of all these codes.
Definition: City route number where the crash occurred.
Additional Information: Computed element, used for linkage with the roadlog element.
Definition: Whether or not a commercial vehicle was involved in the accident.
Additional Information: Element discontinued from 1999 onwards.
Definition: NC county number where the crash occurred.
Definition: Day of the month when the crash occurred.
Additional Information: Format DD where DD = Day of the Month (01-31). Element added in 1998, and discontinued in 2000 onwards.
Definition: Department code of the department who reported to the crash.
Additional Information: New element added in 2000.
Definition: Development Amount
Definition: From Road - used in describing crash location for subsequent mileposting.
Definition: From Road Class - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Direction from Road - used in describing crash location for subsequent mileposting.
Additional Information: Element discontinued from 2000 onwards.
Definition: Hazmat Vehicle in Accident
Additional Information: Element discontinued from 1999 onwards.
Definition: Whether or not the accident was a hit and run.
Additional Information: Element discontinued from 2000 onwards.
Definition: Hour when the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Light condition when the accident occurred.
Definition: Location of the crash in relation to nearby roadway feature.
Additional Information:
1. Some changes in codes for this variable from 2000 onwards. This resulted in some shifts in categories. Some categories were combined, while some categories were differentiated because of this.
2. For 2000 and later years, categories 7 to 12 are coded which describe different types of intersections. Prior to 2000, all intersection related crashes were coded as category 27. Similarly, for 2000 and later years categories 15 to 21 are coded which describe different types of ramp crashes. Prior to 2000, all ramp related crashes were coded as category 28.
* Categories coded before 2000.
** Categories coded after 2000.
Definition: Type of development at crash location.
Definition: Whether or not a motorcycle was involved in the accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Means of Involvement
Additional Information: Element discontinued from 2000 onwards.
Definition: Most harmful event in the crash sequence.
Additional Information: New element added in 2000.
Definition: Milepost
Definition: Month of the year when the accident occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether or not a moped was involved in the accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Direction from municipality to accident - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Distance from the municipality to the crash in miles - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000
Definition: Million Vehicle Miles Traveled
Additional Information: Million Vehicle Miles Traveled on Road Segment. Element discontinued from 2000 onwards.
Definition: Number of lanes at the crash location.
Definition: In or Near Town - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Whether a crash does not meet the minimum reportability requirement.
Additional Information: New element added in 2000.
Definition: Non-Motorist Count
Additional Information: New element added in 2000.
Definition: Number of Vehicle + Pedestrian + Bike
Definition: Number of units involved in the crash.
Definition: Reporting Officer State
Additional Information: New element added in 2000.
Definition: On Road - used in describing crash location for subsequent mileposting.
Definition: On Road Class - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Patrol Area for NC State Highway Patrol.
Additional Information: New element added in 2000.
Definition: Whether or not the accident involved pedestrians.
Definition: Quality of Milepost
Additional Information: Element discontinued from 2000 onwards.
Definition: Population of city where crash occurred.
Additional Information: The unit of this element is thousands for years before 1999. So, if the variable is coded as 10, it indicates 10,000. For later years, the variable is coded as the absolute population, which are 10,000 indicates 10,000.
Definition: Total property damage in dollars as a result of the crash.
Definition: Public Vehicular Area
Additional Information: Element discontinued from 2000 onwards.
Definition: Character of the road where the crash occurred.
Definition: Road configuration where the crash occurred.
Additional Information: All divided highways coded as category 6 for 1999 and earlier years. For 2000 and later years, all divided highways coded as category 3 and category 4.
* Categories present in 1999 and earlier years.
** Categories present in 2000 and later years.
Definition: Road surface type where the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: The condition of the road surface where the crash occurred.
*Categories present in 2000 and later years.
Definition: Distance from FRM_RD in feet - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Distance from FRM_RD in miles - used in describing crash location for subsequent mileposting.
Definition: Location of crash relative to travel lanes.
Additional Information: New element in added in 2000.
Definition: Reportable Status
* Categories present in 2000 and later years.
Definition: Crash ocurred on a ramp or service road.
Additional Information: New element added in 2000.
Definition: Classification of the roadway where the crash occurred.
Additional Information: New element added in 2000.
Definition: Roadway circumstance/condition that contributed to the crash.
Definition: Roadway Class
Additional Information: Element discontinued from 2000 onwards.
Definition: Railroad Crossing Number
Additional Information: New element added in 2000.
Definition: Railroad Cross Not Indicated
Additional Information: Element discontinued from 2000 onwards.
Definition: Mileposted Route
Definition: Rural-Urban Identification
Additional Information: New element added in 2000.
Definition: Whether or not a school bus was involved in the crash.
Additional Information: Element discontinued from 2000 onwards.
Definition: The most severe injury in the crash.
Definition: Computed speed of vehicles involved in accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether a citation was issued to someone in accident.
Additional Information: Element discontinued from 2000 onwards. Almost 100% observations are coded as 0. Use this element with caution.
Definition: Time of day when the accident occurred.
Additional Information: Element discontinued from 1999 onwards.
Definition: Direction toward TO_RD - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Toward Road - used in describing crash location for subsequent mileposting.
Definition: Toward Road Class - used in describing crash location for subsequent mileposting.
Additional Information: New element added in 2000.
Definition: Total number killed in accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Total A Injures in the accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Total B Injures in Accident
Additional Information: Element discontinued from 2000 onwards.
Definition: Total C Injuries in Accident
Additional Information: Element discontinued from 2000 onwards.
Definition: DOT Assigned Town Code
Additional Information: New element added in 2000.
Definition: Traffic control device present at the crash location.
* Categories present in 2000 and later years.
Definition: Whether the traffic control device was operating when the crash occurred.
Definition: Whether or not the traffic control was visible when the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Weather conditions when the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
* Categories coded in 2000 and later years.
Definition: Day of the week that the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether or not weather contributed to the accident.
Additional Information: New element added in 2000.
Definition: Whether or not the crash was in a marked work zone.
Additional Information: New element added in 2000.
Definition: Whether or not there was activity in the work zone when the crash occurred.
Additional Information: New element added in 2000.
Definition: Type of work zone.
Additional Information: New element added in 2000.
Definition: Part of work zone where crash occurred.
Additional Information: New element added in 2000.
Definition: Non-Mileposted Crossing Route Location
Additional Information: Element discontinued from 2000 onwards.
Definition: Zip code of the office who reported to the crash.
Additional Information: New element added in 2000.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO |
|---|---|---|---|---|
| ACTION | DRIVER CHARGED WITH VIOL | Vehicle | CHAR (1) | 71 |
| AIRBAGS | AIR BAGS PRESENT IN VEH | Vehicle | CHAR (1) | 71 |
| AIRDEPL | AIRBAGS DEPLOYED DURING CRASH | Vehicle | CHAR (1) | 72 |
| ALC_DRUG | ALCOHOL/DRUG IN ACC | Vehicle | NUM (8) | 72 |
| ALCFLAG | ALCOHOL FLAG | Vehicle | CHAR (1) | 72 |
| AMTDAMG | AMOUNT OF DAMAGE TO VEH | Vehicle | NUM (8) | 73 |
| AXLE_NBR | COMMERCIAL CARRIER AXLES | Vehicle | NUM (8) | 73 |
| AXLES | NUMBER OF AXLES FOR TRL#1 | Vehicle | NUM (8) | 74 |
| AXLES2 | NUMBER OF AXLES FOR TRL#2 | Vehicle | NUM (8) | 74 |
| BIKEFLAG | BICYCLE FLAG | Vehicle | CHAR (1) | 74 |
| BODY | CARGO BODY TYPE | Vehicle | NUM (8) | 74 |
| CASENO | NC ACCIDENT NUMBER WITH YR | Vehicle | NUM (8) | 75 |
| CC_CITY | COMMERCIAL CARRIER CITY | Vehicle | CHAR (22) | 75 |
| CC_STATE | COMMERCIAL CARRIER STATE | Vehicle | CHAR (2) | 75 |
| CC_ZIP | COMMERCIAL CARRIER ZIP CODE | Vehicle | CHAR (9) | 75 |
| CCB_CITY | COMM CARR BUSINESS CITY | Vehicle | CHAR (2) | 75 |
| CCB_STAT | COMM CARR BUSINESS STATE | Vehicle | NUM (8) | 75 |
| CDL_IND | CDL INDICATOR | Vehicle | CHAR (1) | 76 |
| CNT_SEAT | NUMBER OF SEATS OCCUPIED | Vehicle | CHAR (1) | 76 |
| CONTRIB1 | VIOL/CONTRIBUT FACTOR #1 | Vehicle | NUM (8) | 76 |
| CONTRIB2 | VIOL/CONTRIBUT FACTOR #2 | Vehicle | NUM (8) | 76 |
| CONTRIB3 | VIOL/CONTRIBUT FACTOR #3 | Vehicle | NUM (8) | 76 |
| CONTRIB4 | VIOL/CONTRIBUT FACTOR #4 | Vehicle | NUM (8) | 76 |
| CONTRIB5 | VIOL/CONTRIBUT FACTOR #5 | Vehicle | NUM (8) | 76 |
| CROSSMED | CROSS MEDIAN | Vehicle | CHAR (1) | 77 |
| DAMSEV | TAD#1 SEVERITY | Vehicle | CHAR (1) | 78 |
| DAMSEV2 | TAD#2 SEVERITY | Vehicle | CHAR (1) | 78 |
| DAMSEV3 | TAD#3 SEVERITY | Vehicle | CHAR (1) | 78 |
| DIR_TRVL | DIRECT OF TRAVEL ON | Vehicle | CHAR (2) | 78 |
| DRG_RES | DRIVER ALC/DRUG TEST RESULT | Vehicle | CHAR (8) | 79 |
| DRG_SUSP | DRIVER ALC/DRUG SUSPECTED | Vehicle | CHAR (8) | 79 |
| DRSTATE | OUT OF STATE DRIVERS LIC | Vehicle | CHAR (1) | 79 |
| DRV_AGE | DRIVER/PEDEST AGE | Vehicle | CHAR (3) | 79 |
| DRV_BAC | DRIVER BLOOD ALCOHOL IN % | Vehicle | NUM (8) | 80 |
| DRV_CITY | DRIVER CITY | Vehicle | CHAR (1) | 80 |
| DRV_DOB | DRIVER DATE OF BIRTH | Vehicle | NUM (8) | 80 |
| DRV_INJ | DRIVER/PEDESTRIAN INJURY | Vehicle | CHAR (1) | 81 |
| DRV_LICENSE_RESTRICT | DRIVERS LICENSE RESTRICT | Vehicle | NUM (8) | 81 |
| DRV_RACE | DRIVER/PEDEST RACE | Vehicle | CHAR (1) | 82 |
| DRV_REST | DRIVER RESTRAINT USAGE | Vehicle | CHAR (2) | 82 |
| DRV_SEAT | DRIVER/PEDEST SEAT POS | Vehicle | CHAR (1) | 83 |
| DRV_SEX | DRIVER/PEDEST SEX | Vehicle | CHAR (1) | 83 |
| DRV_ZIP | DRIVER ZIP CODE | Vehicle | CHAR (9) | 83 |
| EMERGUSE | EMERGENCY VEHICLE USE | Vehicle | NUM (8) | 83 |
| EVENT1 | SEQUENCE OF EVENTS 1 | Vehicle | NUM (8) | 84 |
| EVENT2 | SEQUENCE OF EVENTS 2 | Vehicle | NUM (8) | 84 |
| EVENT3 | SEQUENCE OF EVENTS 3 | Vehicle | NUM (8) | 84 |
| EVENT4 | SEQUENCE OF EVENTS 4 | Vehicle | NUM (8) | 84 |
| EXPR_DT | LICENSE EXPIRATION DATE | Vehicle | NUM (8) | 86 |
| FIRE | POSTCRASH FIRE | Vehicle | NUM (8) | 86 |
| GOV_OWN | GOV OWNED VEH INDICATOR | Vehicle | CHAR (1) | 86 |
| GVWR_WGT | COMM CARR GROSS VEH WEIGHT | Vehicle | NUM (8) | 86 |
| HAZ_NUM1 | 1 DIGIT HAZMAT NUM PLACARD | Vehicle | NUM (8) | 86 |
| HAZ_NUM4 | 4 DIGIT HAZMAT NUM PLACARD | Vehicle | CHAR (4) | 87 |
| HAZ_PLAC | HAZMAT PLACARD INDICATOR | Vehicle | CHAR (1) | 87 |
| HAZMAT | HAZARDOUS CARGO | Vehicle | CHAR (1) | 87 |
| IMPACTFT | DIST TRAVEL AFTER IMPACT | Vehicle | NUM (8) | 87 |
| IMPACTSP | IMPACT SPEED | Vehicle | NUM (8) | 88 |
| INSURED | INSURANCE INDICATOR | Vehicle | CHAR (1) | 89 |
| INTOXC | DRIVER INTOXICATION GROUP | Vehicle | NUM (8) | 89 |
| L_PERMIT | LEARNER PERMIT | Vehicle | CHAR (1) | 89 |
| LENGTRL | LENGTH OF TRAILER #1,IN FT | Vehicle | NUM (8) | 89 |
| LENGTRL2 | LENGTH OF TRAILER #2,IN FT | Vehicle | NUM (8) | 89 |
| LIC_IND | DRIVER LICENSE INDICATOR | Vehicle | CHAR (1) | 90 |
| LIC_STAT | LICENSE STATE | Vehicle | CHAR (2) | 90 |
| LICRESTR | RESTRICT ON DRIV LICENSE | Vehicle | CHAR (2) | 90 |
| LICTYPE | TYPE OF DRIVERS LICENSE | Vehicle | CHAR (1) | 91 |
| MAKE | VEHICLE MAKE | Vehicle | CHAR (2) | 91 |
| MAKENAME | VEHICLE MAKE NAME | Vehicle | CHAR (20) | 91 |
| MANEUVER | VEH MANEUVER/PEDEST ACTION | Vehicle | NUM (8) | 92 |
| MISCACT1 | MISCELLANEOUS ACTION | Vehicle | CHAR (2) | 93 |
| MOSTHARM | MOST HARMFUL EVENT | Vehicle | NUM (8) | 94 |
| NUM_A | TOTAL A INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_B | TOTAL B INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_C | TOTAL C INJURIES IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_K | TOTAL KILLED IN VEHICLE | Vehicle | CHAR (2) | 96 |
| NUM_OCCS | TOTAL OCCUPANTS IN VEH | Vehicle | CHAR (2) | 96 |
| NUM_POCS | NO OF POINTS OF CONTACT | Vehicle | CHAR (1) | 96 |
| NUM_TADS | NUMBER OF TAD CODES | Vehicle | CHAR (1) | 96 |
| NUMINJ | TOT INJURED IN VEH (K+A+B+C) | Vehicle | CHAR (2) | 96 |
| NUMVIOLS | NUM OF VIOLS INDICATED | Vehicle | CHAR (1) | 97 |
| OBJECT1 | TYPE OF OBJECT STRUCK | Vehicle | CHAR (2) | 97 |
| ON_RD | ON ROAD | Vehicle | CHAR (8) | 98 |
| ONRD_CL | ON ROAD CLASS | Vehicle | CHAR (4) | 99 |
| OTH_UNIT | OTHER UNIT TYPE | Vehicle | CHAR (20) | 99 |
| OUTSTATE | OUT OF STATE VEH REGIS | Vehicle | CHAR (1) | 99 |
| OWN_CITY | VEHICLE OWNER CITY | Vehicle | CHAR (22) | 99 |
| OWN_STAT | VEHICLE OWNER STATE | Vehicle | CHAR (2) | 100 |
| OWN_ZIP | VEHICLE OWNER ZIP CODE | Vehicle | CHAR (9) | 100 |
| OWNERTYP | OWNER CATEGORY | Vehicle | CHAR (3) | 100 |
| PARK_VEH | INDICATOR OF PARKED VEH | Vehicle | CHAR (1) | 100 |
| PED_LOC | NON-MOTORIST LOCATION | Vehicle | NUM (8) | 101 |
| PEDACT | NON-MOTORIST ACTION | Vehicle | NUM (8) | 102 |
| PEDCONT1 | CONTRIB CIRCUM NON-MOT 1 | Vehicle | NUM (8) | 103 |
| PEDCONT2 | CONTRIB CIRCUM NON-MOT 2 | Vehicle | NUM (8) | 103 |
| PEDFLAG | PEDESTRIAN IN ACCIDENT | Vehicle | CHAR (1) | 103 |
| PEDHITBY | PUPIL PEDEST STRUCK BY (SCHLBUS CRASH) | Vehicle | CHAR (1) | 104 |
| PHYSCOND | PHYSICAL COND OF DRIVER | Vehicle | NUM (8) | 104 |
| PTCONT1 | POINT OF CONTACT #1 | Vehicle | CHAR (2) | 105 |
| PTCONT2 | POINT OF CONTACT #2 | Vehicle | CHAR (2) | 105 |
| PTCONT3 | POINT OF CONTACT #3 | Vehicle | CHAR (2) | 105 |
| PTCONT4 | POINT OF CONTACT #4 | Vehicle | CHAR (2) | 105 |
| PTCONT5 | POINT OF CONTACT #5 | Vehicle | CHAR (2) | 105 |
| RD2OBJST | DISTANCE TO OBJECT STRUCK | Vehicle | NUM (8) | 106 |
| REGION | REGION OF IMPACT | Vehicle | CHAR (1) | 107 |
| ROLLOVER | VEHICLE ROLLOVER | Vehicle | CHAR (1) | 107 |
| ROLLPTCT | ROLLOVER, POINT OF CONTACT | Vehicle | NUM (8) | 107 |
| ROLLTAD | ROLLOVER, TAD SEVERITY | Vehicle | NUM (8) | 108 |
| SCH_BUS1 | SCHOOL BUS CONTACT VEH | Vehicle | NUM (8) | 108 |
| SCH_BUS2 | SCHOOL BUS NON-CONTACT VEH | Vehicle | NUM (8) | 108 |
| SOB_TEST | CHEMICAL TEST GIVEN | Vehicle | NUM (8) | 109 |
| SPDLIM | POSTED SPEED LIMIT | Vehicle | NUM (8) | 109 |
| SPILL | HAZARDOUS CARGO SPILL | Vehicle | CHAR (1) | 110 |
| TIRESKID | TIRE IMPRESSIONS IN FEET | Vehicle | NUM (8) | 110 |
| TOTLENG | TOT LENGTH OF TRAILER(S) IN FEET | Vehicle | CHAR (3) | 110 |
| TOWAWAY | VEHICLE DRIVEABLE | Vehicle | NUM (8) | 111 |
| TOWED_BY | TOWED BY | Vehicle | CHAR (50) | 111 |
| TOWED_TO | TOWED TO | Vehicle | CHAR (50) | 111 |
| TRL_TYPE | TRAILER TYPE | Vehicle | NUM (8) | 111 |
| TRL1_FLG | DATA PRESENT (TRAILER #1) | Vehicle | CHAR (1) | 112 |
| TRL2_FLG | DATA PRESENT (TRAILER #2) | Vehicle | CHAR (1) | 112 |
| TRVL_SPD | ESTIMATED ORIGINAL SPEED | Vehicle | NUM (8) | 112 |
| UNDEROVR | VEHICLE UNDERRIDE/OVERRIDE | Vehicle | NUM (8) | 113 |
| UNIT_TYP | UNIT TYPE | Vehicle | CHAR (1) | 113 |
| V_DAMAG2 | TAD#2 LOCATION | Vehicle | CHAR (2) | 114 |
| V_DAMAG3 | TAD#3 LOCATION | Vehicle | CHAR (2) | 114 |
| V_DAMAGE | TAD#1 (AREA OF DAMAGE) LOC | Vehicle | CHAR (2) | 114 |
| VEH_SEIZ | VEHICLE SEIZURE DWI | Vehicle | CHAR (1) | 114 |
| VEH_DEF | VEHICLE DEFECT | Vehicle | NUM (8) | 115 |
| VEHNO | VEHICLE POSITION NUMBER | Vehicle | NUM (8) | 115 |
| VEHON | VEHICLE LOCATION BASED ON ROAD | Vehicle | CHAR (1) | 115 |
| VEHSEV | SEVERITY | Vehicle | NUM (8) | 115 |
| VEHTYPE | VEHICLE TYPE | Vehicle | NUM (8) | 116 |
| VEHYR | MODEL YEAR OF VEHICLE | Vehicle | NUM (8) | 117 |
| VIN | VEHICLE IDENTIFICATION NO | Vehicle | CHAR (17) | 117 |
| VIN_ID | VEHICLE IDENTIFICATION NO | Vehicle | CHAR (25) | 117 |
| VISION | VISION OBSTRUCTION | Vehicle | NUM (8) | 118 |
| WIDTRL | WIDTH OF TRAILER #1 (IN) | Vehicle | NUM (8) | 118 |
| WIDTRL2 | WIDTH OF TRAILER #2 (IN) | Vehicle | NUM (8) | 118 |
(1) SAS variable names and longer explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
(2) For all SAS-formatted variables below, an extra category labeled as "ERROR CODES" consolidates all values not listed as legitimate codes. This category is printed when variables are listed in tables.
(3) For consistency with other State's files and ease of handling, driver-related variables have been included in this Vehicle Subfile as well as in the Occupant Subfile.
Definition: Whether or not the driver of the vehicle involved in the crash was charged with a violation.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether or not airbags were present in the vehicle when the accident occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Wheter or not the airbag deployed.
Additional Information: Element discontinued from 2000 onwards. There is an increase in the number of observations coded as “Airbags Deployed”. This is because for later years, more vehicles were equipped with air bags.
Definition: Whether alcohol or drugs were involved in the accident.
Additional Information: Element discontinued from 2000 onwards.
Definition: Alcohol Flag
Additional Information: New element added in 2000.
Definition: Amount of damage to vehicle.
Definition: Commercial carrier total number of axles.
Additional Information: New element added in 2000.
Definition: Number of Axles for TRL#1
Definition: Number of Axles for TRL#2
Definition: Whether or not the crash involved a bicycle.
Additional Information: New element added in 2000.
Definition: Cargo Body Type
Additional Information: New element added in 1999. We are unsure about the quality of this element for 1999. From 2000 onwards, the variable appears consistent.
Definition: NC accident number with year for the crash.
Additional Information: Format YYNNNNNN, Where YY = Year, and NNNNNN = CASENUM. Element type is CHAR for 1990 to 1999.
Definition: Commercial Carrier City
Additional Information: New element added in 2000.
Definition: Commercial Carrier State
Additional Information: New element added in 2000.
Definition: Commercial Carrier Zip Code
Additional Information: New element added in 2000.
Definition: Commercial Carrier Business City
Additional Information: New element added in 2000.
Definition: Commercial Carrier Business State
Additional Information: New element added in 2000.
Definition: CDL Indicator
Additional Information: New element added in 2000.
Definition: Number of Seats
Additional Information: Element discontinued from 2000 onwards.
Definition: Violating/Contributing Factor
Additional Information: Elements CONTRIB4 and CONTRIB5 discontinued from 2000 onwards.
* Categories coded for 2000 and later years.
** Categories code for 1999 and earlier years.
Definition: Whether the vehicle crossed the median during the crash.
Additional Information: Element discontinued from 2000 onwards.
Definition: Severity of damage to the vehicle (based on the TAD level).
Definition: Direction of travel of the vehicle when the crash occurred.
Additional Information: Categories coded 1-4 for 1999 and earlier years. For earlier years of data, 1-4 indicated, North, East, South, and West respectively.
Definition: Driver Alcohol/Drug Test Result
Additional Information: New element added in 2000.
Definition: Driver Alcohol/Drug Suspected
Additional Information: New element added in 2000.
Definition: Whether the driver involved in the crash is out of state or not.
Additional Information: Element discontinued from 2000 onwards.
Definition: Age of the driver or pedestrian involved in the crash.
Definition: Driver Blood Alcohol Percentage
Additional Information: New element added in 2000.
Definition: City where the driver involved in the crash is from.
Additional Information: New element added in 2000.
Definition: Date of birth of the driver involved in the crash.
Definition: Driver/Pedestrian Injury
Definition: Whether or not there was a restriction noted on the driver’s license.
Additional Information: Element discontinued from 2000 onwards.
Definition: Race of the driver/pedestrian involved in the crash.
* Category coded from 2000 onwards.
Definition: Type of safety restraint used by the driver.
Additional Information: The data included under this variable is inaccurate, in that regularly conducted field observations of use indicate figures which are at least 10 to 15 percent lower than the values found in the accident file.
* Categories coded from 2000 onwards.
Definition: Driver/Pedestrian Seat Position
Definition: Sex of the driver or pedestrian involved in the crash.
Definition: Zip code of the driver who was involved in the crash.
Additional Information: New element added in 2000.
Definition: Emergency Vehicle Use
Additional Information: New element added in 2000.
Definition: Description of each event in the crash sequence for this vehicle.
Additional Information: New element added in 2000.
Definition: Expiration date of license of the driver involved in the crash.
Additional Information: New element added in 2000.
Definition: Whether or not the crash resulted in a fire.
Additional Information: From 2000 onwards almost 100% observations are coded as missing.
Definition: Government Owned Vehicle Indicator
Additional Information: New element added in 2000.
Definition: Commercial Carrier Gross Vehicle Weight
Additional Information: New element added in 2000.
Definition: 1 Digit Hazmat Number Bottom Placard
Additional Information: New element added in 2000.
Definition: 4 Digit Hazmat Number Bottom Placard
Additional Information: New element added in 2000.
Definition: Hazmat Placard Indicator
Additional Information: New element added in 2000.
Definition: Whether or not the vehicle was carrying hazardous material when the crash occurred.
Additional Information: From 2000 onwards, almost all observations coded as missing.
Definition: Distance traveled by the vehicle after the impact occurred.
Definition: Estimated speed of the vehicle when impact occurred.
Definition: Whether or not this vehicle was insured.
Additional Information: New element added in 2000.
Definition: Driver Intoxication Group
Additional Information: Element added in 1996, and discontinued from 1998 onwards.
Definition: Learner Permit
Additional Information: Element discontinued from 2000 onwards.
Definition: Length of Trailer #1 in Feet
Definition: Length of Trailer #2 in Feet
Definition: Whether or not the driver had a driver’s license.
Additional Information: New element added in 2000.
Definition: State of the license of the driver involved in the crash.
Additional Information: New element added in 2000.
Definition: Restrict on Driver License
Additional Information: Element discontinued from 2000 onwards. For years 1995 and 1996, all categories coded as missing.
Definition: Type of driver license held by the driver of the vehicle involved in the crash.
Additional Information: From 2000 onwards all observations are coded as missing. For 1995 and 1996, all observations coded as 0.
Definition: Make of the vehicle involved in the crash.
Additional Information: Element added in 1999, and discontinued from 2000 onwards.
Definition: Vehicle Make Name
Definition: Vehicle Maneuver/Pedestrian Action
Definition: Miscellaneous Action
Additional Information: Element discontinued from 2000 onwards.
Definition: Most Harmful Event in the crash sequence.
Additional Information:
1. Categories 33-63 are present for 2000 onwards. For earlier years all these information was captured in a single category 68 (hit fixed object).
2. Similarly categories 18, 28, 29 and 32 are present for 2000 onwards. For earlier years they were coded either as Sideswipe (category 96) or other road (category 65).
3. Categories 4.6.7.8.9.11.12 and 13 are coded from 2000 onwards.
4. Categories 65, 66, 68 and 69 coded for years prior to 2000.
Definition: Injuries in Vehicle
Definition: Total number killed in this vehicle.
Definition: Total number of occupants in this vehicle when the crash occurred.
Additional Information: Element discontinued from 2000 onwards.
Definition: Number of Points of Contact
Additional Information: Element discontinued from 2000 onwards.
Definition: Number of TAD Codes
Additional Information: Element discontinued from 2000 onwards.
Definition: Total number of occupants injured in this vehicle (including fatal injuries).
Additional Information: Element discontinued from 2000 onwards.
Definition: Number of Violations Indicated
Additional Information: Element discontinued from 2000 onwards.
Definition: Type of object struck by this vehicle when the crash occurred.
Additional Information: Element discontinued from 2000 onwards. See EVENT1-EVENT4.
Definition: On Road
Additional Information: Element discontinued from 2000 onwards.
Definition: On Road Class
Additional Information: New element added in 2000.
Definition: Other Unit Type
Additional Information: Element discontinued from 2000 onwards.
Definition: Out of State Vehicle Registration
Additional Information: Element discontinued from 2000 onwards
Definition: Vehicle Owner City
Additional Information: Element discontinued from 2000 onwards.
Definition: Vehicle Owner State
Additional Information: Element discontinued from 2000 onwards.
Definition: Vehicle Owner Zip Code
Additional Information: Element discontinued from 2000 onwards.
Definition: Owner Category
Additional Information: Element format changed from 2000 onwards.
Definition: Indicator of Parked Vehicle
Additional Information: New element added in 2000.
Definition: Location of the non-motorist prior to the crash.
Additional Information: New element added in 2000.
Definition: Non-Motorist Action
Additional Information: Categories 1-9 coded for years prior to 2000. For later years, categories 10-18 coded. The categories defined appear to be different and it seems there has been a change in what information is collected by this variable from years prior to 2000 and later years.
Definition: Contributing Circumstances, Non-Motorist
Additional Information: New element added in 2000.
Definition: Whether or not a pedestrian was involved in this accident.
Additional Information: New element added in 2000.
Definition: What struck the pupil pedestrian in a school bus crash.
Additional Information: Element discontinued from 2000 onwards. Almost all observations are coded as missing.
Definition: Physical condition of the driver when the crash occurred.
Definition: Description of each point of contact for this vehicle.
Definition: Location and distance from road to object struck by this vehicle.
Definition: Region of impact for this vehicle.
Additional Information: Element discontinued from 2000 onwards. See Point of Contact.
Definition: Whether or not this vehicle rolled over during the crash sequence.
Additional Information: Element discontinued from 2000 onwards.
Definition: Cross Median
Additional Information: Vehicle Rollover – Determined by Using Point of Contact
Definition: Vehicle Rollover – Determined by Using Tad Severity
Additional Information: Element added in 1996, and discontinued from 1998 onwards.
Definition: Whether or not this vehicle was a school bus and was a contact vehicle in this crash.
Additional Information: New element added in 2000.
Definition: Whether or not this vehicle was a school bus and was a non-contact vehicle in this crash
Additional Information: New element added in 2000.
Definition: Presence and type of chemical test administered to this driver.
Additional Information: For years before 2000 all observations were coded as not stated. Observations coded as categories 1-6 for later years.
Definition: Posted speed limit for this vehicle.
Definition: Whether or not this vehicle spilled hazardous cargo when the crash.
Additional Information: From 2000 onwards almost 100% observations coded as missing.
Definition: Length of tire impressions (skid marks) in feet.
Definition: Total length of all trailer(s) in feet for this commercial motor carrier.
Additional Information: Element discontinued from 2000 onwards.
Definition: Whether or not this vehicle was drivable after the crash (i.e., was not towed from scene).
Definition: Who the vehicle involved in the crash was towed by.
Additional Information: Element discontinued from 2000 onwards.
Definition: Where the vehicle involved in the crash was towed to.
Additional Information: Element discontinued from 2000 onwards.
Definition: Trailer Type
Definition: Data Present (Trailer)
Additional Information: Element discontinued from 2000 onwards.
Definition: Estimated original speed of the vehicle involved in the crash.
Definition: Whether this vehicle underrides (e.g., goes under) or overrides (e.g., runs over) another vehicle in this crash.
Additional Information: New element added in 2000.
Definition: Unit Type
Additional Information: For years prior to 2000 only categories 0 and 2 were coded. Other categories, C, H, O, P and V are coded for later years.
Definition: Area(s) of damage to this vehicle based on TAD location.
Definition: Whether or not this vehicle was seized due to a DWI violation.
Additional Information: New element added in 2000.
Definition: Vehicle Defect
Additional Information: Element renamed in 2000 to veh_def.
Definition: Vehicle Position
Definition: Vehicle Location Based on Road
Additional Information: Element discontinued from 2000 onwards.
Definition: Most severe injury in this vehicle.
Additional Information: Element added in 1998, and discontinued from 1998 onwards.
Definition: Vehicle type of vehicle involved in the crash.
Additional Information: Coding for two-axle trucks changed between 1991 and 1992, when new codes were added (see discussion).
* Categories Present in 2000 and later years.
** Categories present in years prior to 2000.
Definition: Model year of vehicle involved in the crash.
Additional Information: Format YYYY where YYYY = Year.
Definition: Vehicle Identification Number
Additional Information: Element discontinued from 2000 onwards. See next variable.
Definition: Vehicle Identification Number
Additional Information: New variable added in 2000.
Definition: Vision obstruction for this vehicle’s driver that contributed to the crash.
Definition: Width of Trailer #1 (Inches)
Definition: Width of Trailer #2 (Inches)
Additional Information: New element added in 1996.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO |
|---|---|---|---|---|
| AGE | OCCUPANT AGE | Occupant | NUM (8) | 120 |
| AIR_SW | AIRBAG SWITCH STATUS | Occupant | NUM (8) | 121 |
| AIRDEPL | AIRBAG DEPLOYED | Occupant | NUM (8) | 121 |
| CASENO | NC ACCIDENT NUMBER WITH YR | Occupant | NUM (8) | 121 |
| EJECT | EJECTION | Occupant | NUM (8) | 121 |
| EMS_DES | EMERGENCY MEDICAL SERVICE | Occupant | NUM (50) | 122 |
| INJ | OCCUPANT INJURY | Occupant | NUM (8) | 122 |
| PRSN_CTY | PERSON COUNTY | Occupant | CHAR (22) | 122 |
| PRSN_DOB | PERSON DATE OF BIRTH | Occupant | NUM (8) | 122 |
| PRSN_NBR | PERSON NUMBER | Occupant | NUM (8) | 122 |
| PRSN_ST | PERSON STATE | Occupant | CHAR (2) | 123 |
| PRSN_TYP | PERSON TYPE | Occupant | NUM (8) | 123 |
| PRSN_ZIP | PERSON ZIP CODE | Occupant | CHAR (9) | 123 |
| RACE | OCCUPANT RACE | Occupant | NUM (8) | 123 |
| REST1 | OCCUPANT RESTRAINT | Occupant | NUM (8) | 124 |
| SEATPOS | SEATING POSITION | Occupant | NUM (8) | 124 |
| SEX | OCCUPANT SEX | Occupant | NUM (8) | 125 |
| TRAPPED | TRAPPED | Occupant | NUM (8) | 125 |
| TRT_FAC | TREATMENT FACILITY NAME | Occupant | CHAR (100) | 125 |
| VEHNO | VEHICLE POSITION NUMBER | Occupant | NUM (8) | 125 |
(1) SAS element names and longer explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
(2) For all SAS-formatted elements below, an extra category labeled as "ERROR CODES" consolidates all values not listed as legitimate codes. This category is printed when elements are listed in tables.
(3) For consistency with other State's files and ease of handling, driver-related elements have been included in this Occupant Subfile as well as in the Vehicle Subfile.
Definition: Age of occupant in the vehicle involved in the crash.
Definition: Airbag Switch Status
Additional Information: New element added in 2000.
Definition: Whether or not the vehicle’s airbag was deployed when the crash occurred.
Additional Information: New element added in 2000.
Definition: NC Accident Number with Year
Additional Information: Format YYNNNNNN, where YY = Year and NNNNNN = CASENUM. Element type is CHAR for 1990 to 1999.
Definition: Ejection
Additional Information: New element added in 2000.
Definition: Emergency Medical Service
Additional Information: New element added in 2000.
Definition: Injury to the occupant of the vehicle involved in the crash.
Definition: Person City
Additional Information: Element added in 2000 and discontinued from 2009 onwards.
Definition: Date of birth for this occupant.
Additional Information: New element added in 2000.
Definition: Person Number
Additional Information: New element added in 2000.
Definition: Person State
Additional Information: New element added in 2000.
Definition: Person Type
Additional Information: New element added in 2000.
Definition: Person Zip Code
Additional Information: New element added in 2000.
Definition: Race of the occupant of the vehicle involved in the crash.
Definition: Occupant restraint used by this occupant.
Definition: Seating position for this occupant.
Definition: Sex of the occupant in the vehicle involved in the crash.
Definition: Whether this occupant was trapped in the vehicle as a result of the crash.
Additional Information: New element added in 2000.
Definition: Treatment Facility Name
Additional Information: New element added in 2000.
Definition: Vehicle Position Number
Additional Information: Number of vehicle on accident report. The vehicle position number is needed (along with CASENO) for linking this seated occupant to the corresponding vehicle observation in the vehicle file. This information was copied from the North Carolina Vehicle Subfile element named VEHNO.
| SAS VARIABLE NAME | DESCRIPTION | SAS VARIABLE FILE | FORMAT TYPE | PAGE NO |
|---|---|---|---|---|
| AADT | AVER ANNUAL DAILY TRAFFIC | Roadway | NUM (8) | 129 |
| AADT_YR | YEAR OF ADT | Roadway | CHAR (2) | 129 |
| ACCESS | ACCESS CONTROL | Roadway | CHAR (1) | 130 |
| AREATYPE | AREA TYPE | Roadway | CHAR (1) | 130 |
| BEGMP | BEGIN MILEPOST | Roadway | NUM (8) | 130 |
| CNTR_PEAK_ | NUMBER OF LANES IN THE DIRECTION OPPOSITE TO THE PEAK HOUR DIRECTION FLOW | Roadway | NUM (8) | 130 |
| CNTYRTE | COUNTY ROUTE NUMBER | Roadway | CHAR (10) | 131 |
| COUNTY | COUNTY | Roadway | CHAR (2) | 131 |
| DHRVOL | DESIGN HOUR VOLUME | Roadway | CHAR (2) | 132 |
| DIV | HIGHWAY DIVISION ROUTE | Roadway | CHAR (2) | 132 |
| ENDMP | ENDING MILEPOST | Roadway | NUM (8) | 132 |
| FUNC_CLS | FUNCTIONAL CLASS | Roadway | CHAR (2) | 133 |
| FUNC_ST | FUNCTIONAL CLASS (STATE) | Roadway | CHAR (1) | 133 |
| HOV_LN_CNT | NUMBER OF HOV LANES | Roadway | NUM (8) | 133 |
| HOV_TYP_CD | TYPE OF LANES USED FOR HOV EXCLUSIVELY OR DURING SPECIFIED TIME PERIODS | Roadway | NUM (8) | 133 |
| HPMS1 | HPMS SAMPLE ID | Roadway | NUM (8) | 133 |
| IMPROVE1 | TYPE OF RECENT IMPROVEMENT | Roadway | CHAR (2) | 134 |
| INTSTMP | INTERSTATE MILEPOST | Roadway | CHAR (5) | 134 |
| INV_CNTL | INVENTORY CONTROL | Roadway | CHAR (1) | 135 |
| LISTCNTL | LIST CONTROL | Roadway | CHAR (1) | 135 |
| LSHL_TYP | LEFT SHOULDER TYPE | Roadway | CHAR (2) | 136 |
| LSHLDWID | LEFT SHOULDER WIDTH | Roadway | NUM (8) | 137 |
| LT_PARK | LEFT PEAK PARK | Roadway | CHAR (1) | 137 |
| MED_TYPE | MEDIAN TYPE | Roadway | CHAR (1) | 137 |
| MEDWID | MEDIAN WIDTH TOTAL | Roadway | NUM (8) | 138 |
| MVMT | MILLION VEHICLE MILES TRAVELLED | Roadway | NUM (8) | 138 |
| NHS | NATIONAL HIGHWAY SYSTEM | Roadway | CHAR (1) | 138 |
| NO_LANES | NUMBER OF LANES- TOTAL | Roadway | CHAR (1) | 139 |
| ONEWAY_DIR | ONE WAY DIRECTION | Roadway | NUM (8) | 139 |
| PAVECOND | PAVEMENT CONDITION | Roadway | CHAR (2) | 139 |
| PAVED_LSHLDWID | PAVED SHOULD WIDTH (LEFT) | Roadway | NUM (8) | 139 |
| PAVED_RSHLDWID | PAVED SHOULD WIDTH (RIGHT) | Roadway | NUM (8) | 139 |
| PCT_TRK1 | PERCENT TRUCKS | Roadway | CHAR (2) | 140 |
| PEAK_TRK | PERCENT TRUCKS AT PEAK | Roadway | CHAR (1) | 140 |
| PEAKLANE | NUMBER OF LANES IN THE PEAK HOUR DIRECTION OF FLOW | Roadway | NUM (8) | 141 |
| POP_GRP | POPULATION GROUP | Roadway | CHAR (1) | 141 |
| PSTD_RTE_C | POSTED ROUTES | Roadway | CHAR (7) | 141 |
| PTCSTAT | PORTABLE TRAFFIC COUNTER | Roadway | CHAR (8) | 142 |
| RECCONTCD | RECORD CONTINUATION CODE | Roadway | CHAR (1) | 142 |
| RODWYCLS | ROAD WAY CLASS VARIABLE | Roadway | CHAR (2) | 142 |
| ROUGH | PAVEMENT ROUGHNESS | Roadway | CHAR (3) | 142 |
| ROW | RIGHT OF WAY | Roadway | CHAR (2) | 143 |
| RSHL_TYP | RIGHT SHOULDER TYPE | Roadway | CHAR (2) | 143 |
| RSHLDWID | RIGHT SHOULDER WIDTH | Roadway | NUM (8) | 144 |
| RT_PARK | RIGHT PEAK PARK | Roadway | CHAR (1) | 144 |
| RTE_NBR | ROUTE INVENTORIED | Roadway | CHAR (8) | 144 |
| RTE_TYPE | ROUTE TYPE (1ST DIGIT OF RTE_NBR) | Roadway | CHAR (1) | 145 |
| RULURBID | RURAL URBAN IDENTIFICATION | Roadway | CHAR (2) | 145 |
| SCENIC | SCENIC BYWAY | Roadway | CHAR (1) | 145 |
| SEG_LNG | SECTION LENGTH IN MILES | Roadway | NUM (8) | 145 |
| SIGHTDIS | SIGHT DISTANCE | Roadway | CHAR (2) | 145 |
| SPD_LIMT | SPEED LIMIT | Roadway | CHAR (2) | 145 |
| SPEC_SYS | SPECIAL SYSTEM | Roadway | CHAR (1) | 146 |
| STATE_SY | STATE HIGHWAY SYSTEM | Roadway | CHAR (1) | 147 |
| STRCTR_CD | LOCATION OF BRIDGES, TUNNEL AND CAUSEWAYS | Roadway | NUM (8) | 147 |
| STREET_NAM | STREET NAME | Roadway | NUM (20) | 148 |
| SURF_TYP | SURFACE TYPE | Roadway | CHAR (2) | 148 |
| SURF_WID | SURFACE WIDTH TOTAL | Roadway | NUM (8) | 148 |
| TERRAIN | TERRAIN | Roadway | CHAR (1) | 148 |
| TOLL_DIRECTION | TOLL CHARGED | Roadway | CHAR (7) | 149 |
| TOWN | TOWN | Roadway | CHAR (2) | 149 |
| TRFGROW | TRAFFIC GROWTH FACTOR | Roadway | NUM (8) | 149 |
| TRK_RTE | DESIGNATED TRUCK ROUTE | Roadway | CHAR (1) | 149 |
| TRNLNWD | TURN LANE WIDTH | Roadway | NUM (8) | 149 |
| UPDATE_ | UPDATE | Roadway | NUM (8) | 150 |
| URB_LOC | URBAN LOCATION | Roadway | CHAR (1) | 150 |
| URB_POP | RUR/URB DESIGNATED BY POP | Roadway | CHAR (1) | 150 |
| WTDSGSPD | WEIGHTED DESIGN SPEED | Roadway | CHAR (2) | 150 |
| YEAR | YEAR OF TRAFFIC COUNT | Roadway | NUM (8) | 151 |
| YR_IMPR1 | YEAR OF RECENT IMPROVEMENT | Roadway | CHAR (2) | 151 |
| YRADD | YEAR ADDED | Roadway | CHAR (2) | 151 |
SAS element names and longer explanatory names are shown above each listing. (See Discussion for information on SAS formats.)
Definition: Average Annual Daily Traffic
Additional Information: AADT estimates for a roadway segment in the 2001 and earlier files will not necessarily be consistent with estimates in 2002 and later. AADT estimates for road segments with a functional class of rural or urban “local” in 2008 and earlier files are often based on (very) old raw count data. See Discussion.
Definition: Year of ADT
Additional Information: Format YY where YY = Year.
Definition: Access Control
Definition: Area Type
Additional Information: Element discontinued from 2009.
Definition: Begin Milepost
Additional Information: Coincidence routes 1-6 information is also available in the data.
Definition: Number of Lanes in the Direction Opposite To the Peak Hour Direction Flow.
Additional Information: New variable added in 2010.
Definition: County Route Number
Definition: County
Definition: Design Hour Volume
Additional Information: Discontinued from 2008 onwards.
Definition: Highway Division
Additional Information: For data before 2010, City/Town Code has to be combined with DIV (i.e. Highway Division Route) variable to get 4-digit City/Town codes. Contact HSIS staff for more information on codes for the city element.
Definition: Ending Milepost
Additional Information: Coincidence routes 1-6 information is available in the data.
Definition: Functional Class
Definition: Functional Class Provided by the State
Additional Information: Element for internal use. Use the element FUNC_CLS to capture the information about FUNCTIONAL CLASS.
Definition: Number of HOV Lanes
Definition: Type of Lanes Used For HOV Exclusively or During Specified Time Periods.
Definition: HPMS Sample ID
Additional Information: This element was not available from 2002-2008.
Definition: Type of Recent Improvement
Definition: Interstate Milepost
Definition: Inventory Control
Additional Information: Element discontinued from 2009 onwards.
Definition: List Control
Additional Information: Element discontinued from 2009 onwards.
Definition: Left Shoulder Type
Additional Information: This element doesn’t provide information on the inside shoulder for divided highways. It gives the shoulder type for the outside shoulder across the opposite direction travel lanes. Inside shoulder information for divided highways is available for a very few miles and it is not possible to identify those. Hence for all analysis consider this to be the outside shoulder type for the opposite direction travel lane. See discussion section.
New Formats for Data from 2009 onwards
Definition: Width of the left shoulder.
Additional Information: One
Definition: Type of parking on the left side of the road segment during the peak period.
Definition: Median Type
Definition: Median Width –Total
Additional Information: Median width is measured from edge of traveled lane to edge of opposing lane. It includes paved and unpaved inside shoulder width.
Definition: Million Vehicle Miles Traveled
Additional Information: Million Vehicle Miles Traveled
Definition: Whether this roadway section is part of the National Highway System.
Additional Information: New element added in 1993.
Definition: Number of lanes – total for both directions.
Definition: Whether or not this section of road carries traffic in both or only one direction.
Additional Information: New element added in 2009.
Definition: Pavement Condition
Additional Information: Discontinued from 2009 onwards see pvmty_qlty element.
Definition: Paved Shoulder Width (Left)
Definition: Paved Shoulder Width (Right)
Definition: Total Percent Trucks
Additional Information: Here, approximately 90% of the section mileage is coded as “unknown” for years prior to 2000. From 2000 – 2011, only 2% - 6% is coded as “unknown” or zero. The percent estimates in 2011 and earlier are based on “legacy” counts. The 2012 and later percent estimates are based on a new vehicle classification method felt to be more accurate. See Discussion.
Definition: Percent Trucks at Peak
Additional Information: This element is coded as “unknown” or zero for over 75% of the mileage. Element discontinued from 2009 onwards
Definition: Number of Lanes in the Peak Hour Direction of Flow
Additional Information: Number of lanes in the peak hour direction of flow, only if the value is not equals to ½ the number of lanes for undivided roads, or the number of lanes in the peak direction if the road is divided in the LRS. No data indicates that the information can be derived from the Number of Lanes Table.
Definition: Population Group
Additional Information: Categories are defined by size of incorporated area. (See RURUB, URB_POP and Discussion)
Definition: Posted Routes
Additional Information: A system of designated secondary routes where truck traffic with axle weights exceeding 13,000 pounds is prohibited by ordinance. The value is the ordinance number; any value present indicates that the segment is part of the Posted Route system. New variable from 2012.
Definition: Whether or not the crash occurred on a way one direction street.
Additional Information: Variable was discontinued from 2008 onwards.
Definition: Record Continuation Code
Additional Information: New element added in 1999 and discontinued from 2009 onwards.
Definition: Roadway class.
Additional Information: For 2003 and later years, the number of miles available in the system is greater than earlier years. This results in higher mileages for some categories – especially in rural 2-lane and others. See discussion
Definition: Roughness of the pavement.
Additional Information: Discontinued from 2009 onwards.
Definition: Width of right of way.
Definition: Right Shoulder Type
Additional Information: Approximately 3 to 5 percent of the mileage is coded as unknown.
New Formats for Data from 2009 onwards
Definition: Right Shoulder Width
Additional Information: Approximately 12 percent of the mileage have unknown shoulder widths.
Definition: Type of parking on the right side of the road segment during the peak period.
Definition: Route Inventoried
Additional Information: Coincidence routes 1-6 information is also available in the data.
Definition: Route Type (1st Digit of RTE_NBR)
Additional Information: Coincidence routes 1-6 information is also available in the data.
Definition: Rural Urban Identification
Additional Information: New element added in 1992.
Definition: Scenic Byway
Additional Information: New element added in 1999 and discontinued from 2002 onwards.
Definition: Section Length in Miles
Definition: Sight Distance
Definition: Speed Limit
Definition: Special System designator.
Following Formats for Pre 2009 Data
Definition: State Highway System
Additional Information: Discontinued from 2009 onwards.
Definition: Location of Bridges, Tunnels and Causeways
Additional Information: New element added in 2010.
Definition: Street Name
Definition: Surface Type
Definition: Surface Width – Total
Definition: Terrain
Definition: The travel direction, if any, that a toll is charged
Additional Information: New variable in 2012.
Definition: Town
Definition: Traffic Growth Factor
Additional Information: Discontinued from 2009 onwards.
Definition: Designated Truck Route
Definition: Turn Lane Width
Additional Information: New element added in 1992 and discontinued from 2009 onwards.
Definition: Update
Additional Information: Format MM/DD/YY where MM = Month, DD = Day, and YY = Year. New element added in 1999 and discontinued from 2009 onwards.
Definition: Urban Location
Additional Information: Element discontinued from 2002 onwards.
Definition: Rural/Urban Designated by Population
Additional Information: Categories are defined by a combination of the census-related “urbanized area” definition and population groups. (See POP_GRP and Discussion)
Definition: Weighted Design Speed
Additional Information: Calculated value based on degree and lengths of curves of tangents in the HPMS sample section.
Definition: Year of Traffic Count
Additional Information: Format YYYY where YYYY = Year. New element added in 1999 and discontinued from 2009 onwards.
Definition: Year of Recent Improvement
Definition: Year Added
