Vehicles and their occupants in motion have kinetic energy that is dissipated in a crash. The greater the energy that must be dissipated, the greater the chances of severe injury or death. The laws of physics tell us that crash severity increases disproportionately with vehicle speed. A frontal impact at 35 mph, for example, is one-third more violent than one at 30 mph. Higher crash speeds reduce the ability of vehicles, restraint systems, and roadway hardware such as guardrails, barriers, and impact attenuators to protect occupants.
Young drivers speed more often than older drivers.
In a study of drivers on limited access highways, high-speed drivers were more often male and more often judged to be younger than 30. Studies in California have found that the rate of speeding violations per mile traveled is at least three times as high for drivers 16-19 years old as it is for drivers age 30 and older. At all ages, male drivers are more likely than female drivers to be involved in speed-related fatal crashes. The authors of this early study acknowledged that their findings could not be extended to controlled access freeways, but some proponents of higher travel speeds have attempted to do so. Many differences in travel speeds are unavoidable because of the slower speeds of turning or merging vehicles.