During a collision investigation, why are yaw marks not typically used for speed estimates?

During a collision investigation, why are yaw marks not typically used for speed estimates?

• A. Because they are often unclear
• B. Because they are difficult to measure
• C. Because their length varies based on conditions
• D. Because they indicate vehicle direction only

Answer: (C)

Yaw marks are tire marks left on the roadway when a vehicle is turning or sliding, which provides evidence about the vehicle's path and dynamics during an incident. The correct choice highlights that the length of yaw marks can be influenced by various factors, such as road conditions, tire characteristics, and speed. Since the length of the yaw marks can vary significantly depending on these conditions, they do not provide a consistent and reliable measure for estimating speed. For example, a vehicle that travels at a higher speed may produce shorter yaw marks if the surface is slick, while a lower speed might create longer yaw marks on dry asphalt. This variability makes it challenging to ascertain precise speed estimates based solely on yaw marks.

Yaw marks are tire marks left on the roadway when a vehicle is turning or sliding, which provides evidence about the vehicle's path and dynamics during an incident. The correct choice highlights that the length of yaw marks can be influenced by various factors, such as road conditions, tire characteristics, and speed. Since the length of the yaw marks can vary significantly depending on these conditions, they do not provide a consistent and reliable measure for estimating speed.

For example, a vehicle that travels at a higher speed may produce shorter yaw marks if the surface is slick, while a lower speed might create longer yaw marks on dry asphalt. This variability makes it challenging to ascertain precise speed estimates based solely on yaw marks.