While it might seem like raising speed limits would save time on the road, an AAA Foundation for Traffic Study found that isn’t necessarily true.
The AAA Foundation’s research found that raising posted speed limits may do little to save time and improve traffic flow, but could lead to more crashes, injuries and deaths, according to a news release from AAA.
The research results varied across 12 roadway sites that the study examined. All had new posted speed limits. Six were higher and six were lower. The study also includes various types of roads, the news release says.
The results showed:
- Raising posted speed limits was associated with increased crashes on two of three interstate highways.
- Lowering posted speed limits led to fewer crashes in many cases examined, but the likelihood increased for speed limit violations.
- Changes in travel times were small, whether the speed limits were raised or lowered.
“Our study found no one-size-fits-all answer regarding the impact of changing speed limits,” Mark Jenkins, spokesman, AAA – The Auto Club Group, said in the release.
“AAA urges transportation officials to apply a “holistic” approach when setting or changing posted speed limits and prioritize safety over speed and capacity,” Jenkin said.
Speeding is a critical factor in vehicle crashes across the nation.
According to the National Highway Traffic Safety Administration (NHTSA), there were more than 42,000 traffic deaths in 2021 and again in 2022, the highest levels in 16 years, according to the AAA release.
The NHTSA reports that speeding was a factor in nearly 29% of the fatalities in 2021 and 27% in 2022, the release added.
AAA recommends that changes in posted speed limits should consider a range of factors, including but not limited to the type of road, surrounding land use, and historical crash data. AAA supports automated speed enforcement, but says that programs must be carefully implemented to maintain community support, prioritize equity and consistently drive improved safety.
“The movement in statehouses to raise speed limits is happening across the country in at least eight states this year,” Jennifer Ryan, director of state relations for AAA, said in the release. “But the benefits are overrated, and the risks are understated. Increasing speed limits does not always yield the positive results envisioned by traffic planners.”
This study is the third phase of the AAA Foundation research examining the effect of posted speed limit changes on safety.
Published August 16, 2023
