Speed increases the distance needed to stop a vehicle.
In addition, speeding drivers may not be able to judge distances accurately, which puts other vehicles and pedestrians at greater risk. Drivers who run red lights are likely to be speeding. Higher speeds result in higher risks of injury or death in a traffic crash, because vehicles and their occupants in motion have kinetic energy that is dissipated in a crash. Higher speeds reduce the ability of vehicles and restraint systems to protect occupants. Crash severity increases disproportionately with vehicle speed, so a frontal impact at 35 mph is one-third more violent than one at 30 mph.