Increasing speed limits leads to more frequent car accidents, while lowering them leads to fewer accidents, a new AAA analysis concludes. It’s the kind of conclusion that seems obvious on the surface but still needs to be highlighted given how many states seem convinced to increase speed limits it can save drivers time, when in reality all it does is endanger the lives of pedestrians and cyclists.
The report is the latest in a growing body of evidence finding that changing speed limits can have a major impact on US highway safety. AAA analyzed a dozen different types of highways across the US in where half increased their speed limits while the other half reduced them. The group then did a before-and-after assessment to see what kind of impact the altered speed limits had on traffic safety, as well as travel times.
The report is the latest in a growing body of evidence finding that changing speed limits can have a major impact on road safety.
Two of the three highways that increased speed limits experienced higher numbers of accidents, injuries, or deaths. Meanwhile, travel times remained “comparable” to where they were before the limits were raised, dashing expectations that increased speeds would lead to faster trips for drivers. A number of other types of highways that raised speed limits did not see a corresponding increase in crashes, injuries or fatalities, leading AAA to conclude that more investigation is needed.
Lowering speed limits also had a marginal impact on travel times, which could help disprove arguments that changing speed limits comes at the expense of travel time and driver comfort.
Speeding is a critical factor in traffic accidents in the United States. Speeding-related fatalities recently reached a 14-year high, accounting for nearly a third of all traffic fatalities, according to the National Highway Traffic Safety Administration. This is in the midst of an ongoing “crisis” in US road fatalities, with traffic deaths peaking in 2021.
AAA recommends that states take a “holistic approach” to the question of raising or lowering speed limits, including the type of road, surrounding land use, and historical accident data.
“The movement in state legislatures to increase speed limits is happening across the country in at least eight states this year,” said Jennifer Ryan, AAA director of state relations. “But the benefits are overrated and the risks underrated. Increasing speed limits does not always produce the positive results intended by traffic planners.”