What happens to the probability of having a fatal crash as speeds increase from 45 to 60 mph?

As speeds increase from 45 to 60 mph, the probability of having a fatal crash more than doubles. This is due to several factors related to the physics of collision dynamics. When a vehicle's speed increases, the kinetic energy involved in a potential crash also increases significantly. Kinetic energy is proportional to the square of the speed, meaning that when speed doubles, kinetic energy increases by a factor of four (the square of 2).

This increase in kinetic energy results in more severe impacts, making collisions at higher speeds much more dangerous. Research has shown that crash severity, and corresponding probabilities of fatal outcomes, rise exponentially with speed. The doubling of the probability of a fatal crash between these two specific speeds is a reflection of this drastic increase in risk associated with higher speeds.

The context of roadway safety data supports this conclusion, indicating a clear correlation between speed and the likelihood of fatality in collisions. Hence, understanding these statistical trends is crucial for assessing the impacts of speed on road safety and reinforces the importance of adhering to speed limits.