Crash Scene and Crash Vehicle Reference Photos

Crash Scene:


A device utilized to reduce the severity of crashes and damage to vehicles and other structures by absorbing the energy a vehicle possesses and displacing the energy into deformation of the device. By extending this impact period damage and injuries can likely be lessened.
Traffic Crash Scene Attenuator

Back of sign

The rear of sign often has a sticker which identifies the installation date and any subsequent upkeep or maintenance.
Traffic Crash Scene Back Of Sign

Collision Scrubs

Tire marks left by a vehicle during impact as a result of the unusual weight shift, dynamics and/or forces exerted on a vehicle’s tires.
Traffic Crash Scene Collision Scrubs

Dual Skids

Tire marks left by a decelerating set of tandem wheels.
Traffic Crash Scene Dual Skid Marks

Flat Tire Scuff

A distinctive tire mark left by a deflated tire mounted on a vehicle depicting scalloped-edges and evidence of tire “flopping” onto the pavement as the vehicle continues in motion.
Traffic Crash Scene Flat Tire Scuff


The painted white line which borders the outside edge of a roadway. Often will have reflective qualities to assist visibility during inclement weather.
Traffic Crash Scene Fog Line


These ruts are left by a vehicle’s tire often through soft material such as grass or dirt. A close inspection may be able to determine whether vehicle was braking or simply crossing a surface.
Traffic Crash Scene Vehicle Furrows


When vehicles possessing energy impact in such a way as to limit rotation, energy will often be dispersed through various means including heat, noise, vehicular damage, rotation and finally gouging of the roadway surface when energy is dispelled downward.
Traffic Crash Scene Vehicle Gouges

Impending Skids

a.k.a. Shadow skids, the faint marks left by a braking tire prior to visible lockup of the tires usually determined by visible skid marks. These impending skids quickly wear away due to traffic and weather.
Traffic Crash Scene Impending Skid Marks

Offset Skids

A distinct angle change in a skid mark resulting from impacting a significant object with enough mass to redirect the skidding vehicle.
Traffic Crash Scene Offset Skid Marks

Pavement Edge

Pavement is normally applied in several consecutive layers and packing occurs between to ensure compaction of the surface. The outside edge of the pavement may become too steep either from wash-out of loose material or resurfacing efforts leaving a significant drop-off which could lead to an accident.
Traffic Crash Scene Pavement Edge

Police paint marks

Most officers and departments instruct officers to mark final rests of vehicles, pedestrians and valuable physical evidence with spray paint to ensure collection and documentation is properly completed.

Redirection Gouges

Gouges are usually indicative of a vehicle that has exhausted all other avenues for dispersing energy. Often in collisions involving vehicles with significantly different weights, the smaller vehicle may be redirected from its original path and this change may be depicted through gouging in the roadway surface.
Traffic Crash Scene Redirection Vehicle Gouges


Typically the result of a damaged vehicle and/or part contacting the roadway surface following impact and leading in the direction of final rest.
Traffic Crash Scene Roadway Surface Scrapes


Tire marks normally associated with a braking vehicle.
Traffic Crash Scene Vehicle Skid Marks


Skid marks associated with a dual wheel assembly when bouncing occurs. Commonly found in unloaded tractor-trailers and spacing between marks are usually no more than 24” and ARE NOT the result of a driver’s repetitive brake application.
Traffic Crash Scene Skip Skid Marks

Crash Vehicles:


these groupings of scrapes are usually the result of contact with a uneven surface such as a roadway surface or concrete “jersey barrier”. Different directions of abrasions suggest the number of rollovers.
Traffic Accident Vehicle Abrasions

Airbag Deployed

Traffic Accident Vehicle Airbag Depoyed

Brake Chambers

Devices essential to an air brake system contain large springs and utilize air pressure to compress and decompress springs in efforts to brake the vehicle or release the brakes to allow for travel.
Traffic Accident Vehicle Brake Chambers

Cold Fracture

Lamp bulbs which were not in use at the time of crash may fracture near the posts usually indicative of a filament not illuminated meaning lamps were not in usage at the time of impact.
Traffic Accident Cold Fractured Lamp Bulbs

Dashboard Gauges

Traffic Accident Vehicle Dashboard Gauges

Data Link Connector (DLC)

This connection fond underneath the steering area and dash of a vehicle provides a link to the computer components of a vehicle including the air bag module.
Traffic Accident Vehicle Data Link Connector

Department Of Transportation Number on Tires

The last 4-digits of a DoT number usually stamped into a tire near the wheel rim identifies the week and year of production. For example the number 4208, would reveal this tire was produced the 42nd week of 2008.
Department Of Transportation Number On Tires

Eaton Vorad Unit

A radar based post manufacture accident avoidance system utilized my some carriers and capable of capturing and preserving crash related data including speeds, braking, evasive maneuvers etc.
Eaton Vorad Accident Avoidance System

Eaton Vorad Side Sensor System

ECM-Engine Control Module

The “brains” of the engine, capable of identifying malfunctions within the engine and regulating the performance of an engine. Can also capture crash-related data once a specific trigger has been set usually a substantial decrease in speed within 1 second. (Ex. 9 mph/1sec)
Traffic Accident Vehicle Engine Control Module

Fifth Wheel

The device mounted to the rear of a tractor or larger pick-ups which allows for coupling with a commercial sized trailer.
Traffic Accident Vehicle Fifth Wheel

Frayed Strap

Federal Motor Carrier Safety Regulations specify when straps responsible for securing loads on a commercial vehicle are to be replaced.
Traffic Accident Load Securing Frayed Strap

Headlamp Switch Position

Traffic Accident Headlamp Switch Position

Hot Shock

The distortion of a filament within an enclosed glass bulb signifying the filament was illuminated when impact occurred. This distortion will be significantly more than “age sag”, a slight sloping of the filament due to age and wear. Hot shock is usually very distinctive.
Traffic Accident Vehicle Hot Shock


Often when two vehicles or a vehicle and an object impact, a discernible pattern, shape or imprint will be visible on one of the vehicles.
Traffic Accident Vehicle Impact Impression

Traffic Accident Vehicle Impact Impression

Impaled Vehicle

Guardrails are required to have end treatments to prevent this from occurring.
Traffic Accident Impaled Vehicle


The attachment point or pin mounted on a trailer which connects to the fifth-wheel of the tractor to allow for towing.
Traffic Accident Trailer King Pin

Knee Bolster Damage

The area directly in front of the knees of a driver, some vehicles offer small airbags for this area to reduce injuries to the lower extremities.
Traffic Accident Knee Bolster Damage


Always document the odometer/mileage a vehicle displays because this may be relevant to crash data recordings in commercial vehicles.
Traffic Accident Odometer

Paint Transfer

Whenever two or more vehicles impact each other, often there is a swapping of paint between vehicles and the color depicted on the other is not always an accurate sample but more of a color “family”.
Traffic Accident Vehicle Impact Paint Transfer

PCM (Power Control Module)

A second device on some Ford vehicles underneath the hood, which may retain crash related data temporarily.
Traffic Accident Vehicle Power Control Module


The device mounted on the seat belt which retracts the belt in the event of a collision to further restrain the occupant. These devices may have mechanical, pyrotechnic or electric trigger mechanisms.
Traffic Accident Vehicke Seat Pretensioner

PDOF (Principle Direction of Force)

The direction from which the impacting force was applied to the vehicle. Usually can be determined by a damage analysis, in other words, documenting a part’s original location versus its location after impact.
Traffic Accident Principle Direction Of Force

RCM Restraint Control Module

Ford’s version of an air-bag module or crash data recorder.

Rear End Protection Bar

The device mounted to the rear of commercial trailers as required by Federal Motor Carrier Safety Regulation 393.86
Traffic Accident Vehicle Rear End Protection Bar

Reflective Conspicuity Tape

The red and white reflective tape required to be attached to certain areas of a commercial trailer by Federal Motor Carrier Safety Regulation 393.11
Traffic Accident Reflective Tape

SDM-Sensing Diagnostic Module

The air bag module or “Black-Box” in vehicles, often capable of storing crash related data.
Traffic Accident Vehicle Sensing Diagnostic Module


Post collision analysis may be able to confirm usage.
Traffic Accident Seatbelt Analysis

Slack Adjusters

Traffic Accident Vehicle Slack Adjusters

Traffic Accident Vehicle Slack Adjuster Diagram

Part of the air

Braking system of a commercial vehicle’s which uses pressurized air to compress or decompress a spring and allow for braking a vehicle.


Traffic Accident Vehicle Speedometer

Steering wheel-deformed

A deformation in the steering wheel could suggest or confirm seatbelts were not being used.
Traffic Accident Steering Wheelt Deformation


Traffic Accident Vehicle Tachometer

Tire Condition

Always note tire condition, size and tread depth and any abnormal wear indications along the tread.
Traffic Accident Tire Condition

Trailer Ball Hitch

The device on which a non-commercial trailer connects to a hauling vehicle such as a pickup. Once trailer is connected, should be a securing lock to keep the two connected and always check for emergency chains.
Traffic Accident Vehicle Trailer Ball Hitch

Tire Tread Depth Gauge

A small gauge capable of measuring tire tread usually to the 1/32”.
Traffic Accident Vehicle Tire Tread Depth Gauge

VIN Plate

The plate mounted in a vehicle which contains manufacturer’s data including Vin and usually manufacturer month/year.
Traffic Accident Vehicle Identification Number Plate