Minnesota cities have lowered their speed limits. Has it slowed drivers down?

Brightly colored banners on Richfield streetlights remind drivers there’s a new speed limit in town: “Slower is scenic. Richfield Drives 25.″

The 5 mph decrease in speed limits on residential streets took effect in June, when Richfield joined other metro-area cities, from Minneapolis and St. Paul to Bloomington, Victoria and New Brighton, pushing drivers to slow down. Now Farmington is also considering changes; this month its City Council asked staff to look into the cost of studying the southern suburb’s speed limits.

But does lowering the local limit actually slow drivers down? It’s complicated.

“Some of them don’t notice the change because they’ve driven that way for so many years and it’s been that speed limit, so it’s muscle memory,” Richfield Police Chief Jay Henthorne said, though he added he thinks there’s been an overall reduction in speeds.

Research from the University of Minnesota found St. Louis Park drivers slowed down an average of 1 to 2 mph after the city lowered its default speed limit to 20 mph. The findings were in line with similar studies done elsewhere.

City engineers are well aware that changing the posted speed isn’t like waving a magic wand to slow drivers down. But they say being able to make these changes at the city level is useful.

“It’s a tool,” Richfield City Engineer Joe Powers said. “It’s one of a lot of things that can influence safer driving practices.”

Local governments could go to the state Department of Transportation (MnDOT) to ask for an exception, a process that required a speed study. MnDOT would study speeds on the given road, then set the new speed limit within a specified range of how fast drivers actually go.

The detailed process made it difficult to change speeds — until Minnesota changed its law in 2019.

That change was prompted by Minneapolis seeking state permission to lower its residential speed limits out of concern for pedestrian safety.

The Legislature opted to give local officials around the state the ability to set speed limits on roads in their jurisdictions, provided they based them on traffic analysis, engineering and other guidelines.

Powers said discussions about changing the speed limit in Richfield followed the 2019 legislation, as well as requests from residents to address speeding concerns.

Powers said the new speed limits have been generally popular. Many residents put up lawn signs celebrating the changes — and reminding their neighbors to slow down. He said the effects of the changes are not clear yet, but they’re something the city plans to study as drivers have a chance to adjust.

St. Paul has not done a detailed evaluation of its speed limits since it lowered them, including a new residential limit of 20 mph, though feedback has generally been positive, Public Works spokesperson Lisa Hiebert said in an email.

Minneapolis, which also lowered its speed limits in 2020, is planning a detailed evaluation of speeds and crash data to be completed in 2026, a city spokesperson said.

This month in Texas, a prankster put up a fake 60 mph speed limit sign in a 30 mph zone in Houston. A Houston Landing reporter who spent time at the scene observed that drivers appeared to be following the 30 mph limit anyway.

While there’s a perception that speed limits alter driver behavior, significantly taming them requires physical changes to roadways that promote slower speeds and/or speed limit enforcement, according to a Minnesota Local Road Research Board report.

Factors that can slow down drivers include the road width, the sharpness of curves and the smoothness of pavement, said the University of Minnesota’s Gary Davis, who studied St. Louis Park’s speed change.

Davis found variability in drivers’ speeds after limits changed in St Louis Park. He said he doesn’t have a definitive explanation for that, but said it’s possible some drivers continue the same behavior while others change in response to new speed limits.

“To a large extent, driving is kind of habitual,” Davis said. “You do it over and over and over again and it becomes more of a habit than anything else, and changing a habit is not the easiest thing in the world to do.”

Davis noted that automation features, like displays on cars that remind drivers of the speed limits or cars that drive themselves at the posted speed, could increase adherence to speed limits in the future.

Richfield’s decision to lower residential speed limits to align with driver behavior is consistent with research. While the city can’t change its roads overnight, over time, Powers said the city plans to design roads to be safer, too.

The discussion started with the law change and after COVID-19 brought more bicyclists and pedestrians onto the city’s streets, Director of Community Assets and Development Craig Schlichting said.

Speed studies found drivers going an average of 27 mph on many affected roads, so 25 mph “wouldn’t be a large lift for seeing some general compliance,” Schlichting said.

Like Richfield, New Brighton has a plan to encourage slower speeds in other ways. That includes rethinking road design and adding sidewalks near commercial and government areas.