Raising speed limits leads to more car crashes, while lowering them leads to fewer crashes, a new analysis from AAA concludes. It’s the kind of conclusion that seems obvious on the surface, but still needs to be emphasized how many states seem convinced that increase speed limits can save drivers time, when in fact it only endangers the lives of pedestrians and cyclists.
The report is the latest in a growing body of evidence showing that changing speed limits could have a major impact on road safety in the US. AAA analyzed a dozen roads of various types in the US, half of which raised the speed limit and the other half lowered the limit. The group then carried out a pre- and post-assessment to see what impact the changed speed limits had on road safety and travel times.
The report is the latest in a growing body of evidence showing that changing speed limits can have a major impact on road safety
Two of the three highways that increased speed limits experienced more accidents, injuries or deaths. Meanwhile, commute travel times remained “similar” to how they were before the limits were raised – undermining the expectation that higher speeds would lead to faster journeys for drivers. A number of other road types that increased speed limits did not see a corresponding increase in crashes, injuries or deaths, leading the AAA to conclude that more research is needed.
Reducing speed limits also had a marginal impact on travel times, which could help to undermine arguments that changing limits is at the expense of travel time and driving comfort.
Speeding is a critical factor in road accidents in the US. Speeding-related fatalities recently reached their highest level in 14 years, representing almost a third of all road fatalities. This is reported by the National Highway Traffic Safety Administration. This is amid an ongoing “crisis” in road fatalities in the US, with traffic fatalities peaking in 2021.
AAA recommends that states take a “holistic approach” to the issue of raising or lowering speed limits, including road type, surrounding land use, and historical accident data.
“The movement in state homes to raise speed limits is happening nationwide this year in at least eight states,” said Jennifer Ryan, director of state relations for AAA. “But the benefits are overestimated and the risks are underestimated. Raising speed limits does not always produce the positive results that traffic planners had in mind.”
