There is a clear relationship between increased speed and the risk of traffic accidents and fatalities. While there isn't a single specific speed threshold where risk suddenly spikes, the data shows that even small increases in speed can significantly raise the danger:

Higher speeds directly correlate with increased fatality rates. A study found that a 5 mph increase in the maximum speed limit was associated with an 8% increase in fatality rates on interstates and freeways, and a 3% increase on other roads.

The risk of death rises dramatically as impact speeds increase. A person hit by a car traveling at 35 mph is five times more likely to die than someone hit by a car going 20 mph.

Small reductions in speed can lead to large safety improvements. A 1 mph reduction in operating speeds can result in a 17% decrease in fatal crashes.

The relationship between speed and risk is not linear - higher speeds disproportionately increase danger. For example, increasing driving speed from 60 mph to 80 mph (a 33% increase) raises the risk of a fatal crash by 4 times (a 300% increase).

At higher speeds, drivers have less time to react and vehicles require longer stopping distances. A driver going 40 mph travels twice as far before stopping compared to a driver at 25 mph.

In 2022, speeding was a factor in 29% of all traffic fatalities in the U.S., resulting in 12,151 deaths.