Help: Variables Used in the Data

Three sets of variables are available for creating tables. The list that you select variables from changes depending on whether you are counting crashes, vehicles or people.


When counting crashes:

Access Control – The degree of access to a roadway as controlled by public authority. An interstate has full access control.

Accident Type – Crash typing that incorporates injury level and location.

Alcohol Flag – Indicates whether or not any driver was suspected of alcohol impairment.

Ambient Light – The type of light that existed at the time of the crash. Extremely cloudy conditions may be classified as dawn or dusk if the ambient light conditions are similar.

Bicycle Flag – Indicates whether or not a bicycle was involved in the crash.

Contributing Circumstances Roadway 1 – Apparent condition of the road which contributed to the crash.

Contributing Circumstances Roadway 2 – Apparent condition of the road which contributed to the crash in addition to that listed in Contributing Circumstances Roadway 1.

Crash City – The city or town where the crash occurred

Crash County – The county where the crash occurred

Crash Severity – The injury severity of the worst injury sustained in the crash.

Day of Week – The day of the week on which the crash occurred.

Development Type – The predominant type of development in the area in which the collision occurred.

First Harmful Event – The first injury or damage producing event which led to the crash.

Hour of Day – The hour during which the crash occurred.

Is In Or Near Town – Indicates whether the crash occurred within the limits('in') or outside the limits('near') of the indicated incorporated city or town.

Is Ramp or Service Road – Indicates that the referenced 'on road' is an interchange ramp or service road.

Locality – The general type and level of development in the vicinity of the collision.

Month of Crash – The month during which the crash occurred

Most Harmful Event – The event which produced the greatest property damage or most severe injury in the crash.

NCDOT Division – The NCDOT division for the county in which the crash occurred.

NCSHP Troop Area – The Highway Patrol Troop area for the county in which the crash occurred.

Non-Motorist Count – Total number of non-motorist units in the Crash.

Non-Reportable – A reportable crash must include a fatality, injury, property damage of $1,000 or property damage of any amount to a vehicle seized. A reportable crash must occur on a trafficway or occur after the motor vehicle runs off the roadway but before events are st

Number of Lanes – The total number of thru lanes at the point of the crash.

Number of Units – Total Number of units involved in the crash. A unit is any motor vehicle, pedestrian, pedalcyclist, moped or other road vehicle, excluding railway vehicles.

Older Driver(65+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 64.

Older Driver(75+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 74.

On Road Class – On Road route class. Example: US, NC, I

Pedestrian Flag – Indicates whether or not a pedestrian was involved in the crash.

Relation to Roadway – The specific location of the first harmful event in the crash.

Reporting Agency – Indicates whether crash was reported by the Highway Patrol or by another agency.

Road Character – The change in horizontal direction of the roadway at the location of the crash.

Road Classification – The class of roadway at the crash location. The highest class applicable is listed. For example, a road that is both a US and NC routes will be classified as US route.

Road Configuration – A code indicating whether or not a trafficway is divided and whether it is one- or two-way. A median must be present for a divided road.

Road Surface Condition – Describes the roadway surface conditions at the time and place of the crash.

Road Surface Type – Actual surface type of the roadway in the area in which the crash occurred.

Roadway Feature – Specific road feature at the location of the first harmful event in the crash.

Rural/Urban Indicator – Indicates whether the crash occurred in a rural or an urban area.

Speed Flag – Indicates whether or not any driver in the crash had a contributing circumstance involving speed.

Teen-Involved Crash – Indicates whether or not any driver in the crash is age 16-19

Traffic Control Device – The kind of traffic control device present at the crash site.

Traffic Control Operating – Indication of whether a traffic control device was operating properly at the time of the crash.

Vehicle Count – Total number of vehicle units in the Crash.

Weather Condition1 – The general atmospheric conditions that existed at the time of the crash.

Weather Condition2 – A general atmospheric condition that existed at the time of the crash in addition to that listed in Weather Condition1.

Weather Contrib. To Crash – An indication, in the officer's opinion, as to whether or not weather was a contributing factor in the crash.

Work Zone Activity – Indication of work activity in the work zone at the time of the crash.

Work Zone Area – Type of work zone area in or near which the crash occured.

Work Zone Crash Location – Location of the crash relative to the work zone.

Work Zone Marked – Indication of warning signs, cones, etc., marking the work zone.


When counting vehicles:

Accident Type – Crash typing that incorporates injury level and location.

Cargo Body Type – Cargo body type includes such categories as bus, concrete mixer, garbage, and log truck.

Commercial Carrier Gross Vehicle Weight Rating – The commercial motor vehicle’s gross weight rating.

Commercial Carrier State – State of the commercial carrier company.

Contrib. Circumstances, Non-Motorist 1 – The first circumstance for or action by the non-motorist which may have contributed to the crash.

Contrib. Circumstances, Non-Motorist 2 – The second circumstance for or action by the non-motorist which may have contributed to the crash.

Crash City – The city or town where the crash occurred.

Crash County – The county where the crash occurred

Day of Week – The day of the week on which the crash occurred.

Distance and Direction From Object Struck – If an object was struck, the distance and direction from the edge of the roadway.

Driver Age Group – Age of driver.

Driver Alcohol/Drugs Suspected – Investigating police officer's assessment of whether alcohol or other drugs were used by the vehicle driver or non-motorist.

Driver Alcohol/Drugs Test Results – Indication of the degree of presence of alcohol or other drugs through testing.

Driver Alcohol/Drugs Test Status – Whether or not a test, including the type, was given or refused.

Driver Contrib. Circumstances 1 – The first action of the driver which may have contributed to the crash.

Driver Contrib. Circumstances 2 – The second action of the driver which may have contributed to the crash.

Driver Contrib. Circumstances 3 – The third action of the driver which may have contributed to the crash.

Driver Physical Condition – The condition of the driver or non-motorist at the time of the crash.

Driver State – Identifies the state in which the driver or non-motorist currently resides.

Driver Vision Obstruction – Description of what prevented the driver or non-motorist from seeing whether or not movement(s) could be made in a safe manner.

Emergency Vehicle Use – Indicates that a vehicle involved in the crash was on an emergency response call, with physical emergency signals in use. NOTE: it appears that this variable is being misused to indicate the emergency vehicles CALLED as responders to the scene.

Estimated Damage Amount – Dollar estimate of the cost to restore the vehicle to its condition just prior to the crash or an estimate of the value of the vehicle prior to the crash - whichever is less.

Estimated Speed – Speed the vehicle was traveling prior to impact.

Government Owned Vehicle Indicator – Indicates the vehicle involved in the crash was owned by Government.

Hour of Day – The hour during which the crash occurred.

Insurance Indicator – Indicates whether or not the vehicle was insured.

Length of Tire Impressions – Length, in feet, of tire impressions (skid marks, tire print yaw) for vehicle prior to impact.

License State – Identifies the State that issued the driver’s license to the driver or non-motorist.

Month of Crash – The month during which the crash occurred

Most Harmful Event for Vehicle – The most harmful injury or damage producing event for this vehicle. This may or may not coincide with events listed in Sequence of Events 1-4.

NCDOT Division – The NCDOT division for the county in which the crash occurred.

NCSHP Troop Area – The Highway Patrol Troop area for the county in which the crash occurred.

Non-Motorist Action – The actions of the non-motorist, in the investigating officer's opinion, just prior to the crash.

Non-Motorist Location Prior to Crash – The location of the non-motorist, in the investigating officer's opinion, just prior to the crash.

Older Driver(65+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 64.

Older Driver(75+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 74.

On Road Class – On Road route class. Example: NC, US< I

Other Unit Type – Further description when unit type is 'other'.

Pedestrian Flag – Indicates whether or not a pedestrian was involved in the crash.

Sequence of Events 1 – The first injury or damage producing event for this vehicle.

Sequence of Events 2 – The second injury or damage producing event for this vehicle.

Sequence of Events 3 – The third injury or damage producing event for this vehicle.

Sequence of Events 4 – The fourth injury or damage producing event for this vehicle.

Speed Flag – Indicates whether or not any driver in the crash had a contributing circumstance involving speed.

Speed Limit – Authorized speed limit for the vehicle at the time of the crash.

Speed at Impact – Reflects the speed of the vehicle at the moment of impact.

Teen-Involved Crash – Indicates whether or not any driver in the crash is age 16-19

Trailer Type – Type of trailer pulled by the vehicle.

Travel Distance After Impact – Distance, in feet, vehicle or pedestrian traveled after impact as a result of the force of the collision.

Unit Type – Indicates the type of unit involved in the crash, (ie, vehicle, pedestrian, other)

Vehicle Drivable – Indicates whether the vehicle was disabled by damage severe enough to prevent driving.

Vehicle Make – Make of the vehicle (eg, Chevrolet, Ford)

Vehicle Manuever – The actions of the driver, in the investigating officer's opinion, just prior to the crash.

Vehicle Seizure DWI – Indicates whether or not alcohol or other drugs were involved in sufficient amount to constitute a DWI and the vehicle is "seized."

Vehicle Style – Style of vehicle - more extensive than Unit Type.

Vehicle Underride / Override – An underride refers to a vehicle sliding under another vehicle during a crash. An override refers to a vehicle riding up over another vehicle.

Vehicle Year – Model year of the vehicle.


When counting people:

Accident Type – Crash typing that incorporates injury level and location.

Age Group – Age group of person.

Air Bag Deployed – The deployment status of the airbag for the seat this person occupied.

Air Bag Switch Status – The on/off status of the airbag switch for the seat this person occupied.

Crash City – The city or town where the crash occurred.

Crash County – The county where the crash occurred

Day of Week – The day of the week on which the crash occurred.

Ejection – Whether or not the person was partially, fully, or not ejected from the vehicle as a result of the crash.

Ethnicity – The ethnic affiliation of the person.

Gender – The sex of the person.

Hour of Day – The hour during which the crash occurred.

Injury Status – The most severe injury sustained by this person.

Month of Crash – The month during which the crash occurred

NCDOT Division – The NCDOT division for the county in which the crash occurred.

NCSHP Troop Area – The Highway Patrol Troop area for the county in which the crash occurred.

Occupant/Motorist Protection – The occupant or non-motorist protection used by this person (restraints, helmets, etc.)

Older Driver(65+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 64.

Older Driver(75+)-Involved Crash – Indicates whether or not any driver in the crash is older than age 74.

Person Type – The role of the person in the crash (driver, passenger, etc.)

Seating Position – The location of the person prior to the crash.

Speed Flag – Indicates whether or not any driver in the crash had a contributing circumstance involving speed.

Teen-Involved Crash – Indicates whether or not any driver in the crash is age 16-19

Trapped – Indicates whether the person was restrained in the vehicle after the crash by damaged vehicle components.