Analyzing Skid Marks and Tire Impressions

In a car accident where fault is not easily determined, investigators may engage in crash reconstruction. This involves a significant amount of analysis.

Investigators will gather all the evidence they can to determine what happened and who caused the accident. Skid marks and tire impressions are among the most valuable physical evidence at a crash scene. When properly analyzed, they can reveal critical details about vehicle speed, braking behavior, steering input, point of impact, and driver reaction time.

Skid marks occur when tires slide across the pavement due to hard braking or loss of traction. Tire impressions form when tires maintain partial traction while the vehicle is turning sharply or skidding sideways. Both types of marks help investigators reconstruct pre-impact vehicle movement.

Tires are available in many sizes and tread designs, so it is also important for investigators to understand the various components of a tire:

• Tread blocks: The raised rubber segments that make direct contact with the road
• Grooves: Channels cut between tread blocks
• Sipes: Thin slits cut into tread blocks
• Shoulder: The outer edge of the tread where it meets the sidewall
• Ribs: Continuous raised strips that run around the circumference of the tire

When examining tire tracks, a track represents a negative imprint of the tire tread. To identify the tire responsible, investigators compare the track to suspect tires, analyzing the features listed above. Specific points of comparison between the track and the tire can help determine a match.

Key Information Skid Marks Can Reveal

• Vehicle speed before braking. By measuring the length and darkness of skid marks, investigators can calculate an estimated speed at the time braking began. This is done using physics-based formulas that account for:
  • Road surface conditions.
  • Tire friction.
  • Road slope.

Longer skid marks usually indicate higher speeds, while short or faint marks suggest lower speeds or delayed braking.

• Driver reaction time. The distance between where the driver should have reacted and where braking began helps determine:
  • Whether the driver was distracted.
  • Whether impairment or fatigue may have delayed braking.

Delayed braking often supports negligence claims in civil cases.

• Direction of travel. The angle, curvature, and alignment of tire marks show:
  • Lane position before impact.
  • Sudden lane changes.
  • Loss of control.
  • Swerving to avoid obstacles.

Curved tire impressions can indicate overcorrection or aggressive steering.

• Point of impact. Skid marks often terminate at the collision point, helping investigators identify:
  • The exact location of impact.
  • Which vehicle crossed lanes.
  • Whether a vehicle ran a red light or stop sign.

This is especially important in intersection crashes and multi-vehicle collisions.

Contact a Personal Injury Lawyer

Determining liability in car accidents can be complicated, especially when multiple vehicles are involved. Who caused the crash? In many cases, the tires can tell a lot about what happened.

After a crash, you need someone to provide you with legal advice and help you with physical and financial recovery. A Houston car accident attorney from The West Law Office, PLLC can guide you through the process. To schedule a consultation, fill out the online form or call (281) 347-3247.

Source:

cms.unl.edu/ianr/forensic-science-degree-program/sites/unl.edu.ianr.forensic-science-degree-program/files/360/tire-tracks.pdf