Do lower speed limits on city streets actually slow down drivers?

A change in state law enacted in 2019 gave cities the ability to set speed limits on streets under their jurisdiction after conducting a study, without having to get permission from the Minnesota Department of Transportation.

In the years that followed, Minneapolis, St. Paul and several metro area suburbs took advantage and dropped speed limits from the statutory speed of 30 mph to 25 mph or even 20 mph. But have they been effective in slowing down drivers?

“The jury is still out,” said Gary Davis, a professor in the Civil, Environmental and Geo-Engineering Department at the University of Minnesota. “If you change signs but don’t do any other changes, what effect does that have on how fast a driver is going?”

Davis and researchers from the U’s Center for Transportation Studies teamed up with St. Louis Park to carry out a before-and-after study. Both the city and the U looked at how fast motorists drove on residential streets before the west metro suburb reduced speed limits in 2021, and after new signs went up.

St. Louis Park also handed out more than 600 lawn signs that read “20 is Plenty” over a two-year period and placed portable electronic speed boards throughout the city to augment efforts to educate drivers about lower speed limits.

Results showed motorists generally drove faster than the newly posted speed limits, with the lowest level of compliance on streets that were signed at 20 mph, Davis said. But overall speeds across the city — including on streets where the speed limit did not change — decreased by 1 to 2 mph. The average speed of most drivers in the west metro suburb is now within 5 mph of the posted speed limit, the study found.

“It was a slight reduction,” St. Louis Park engineering project manager Jack Sullivan said in a webinar discussing the topic. “We are trending in the right direction.”

Studies show there is little change in speed patterns after a lower speed limit is posted. Drivers are much more influenced by changes to the roadway, its environment and conditions, the Minnesota Department of Transportation said.

Davis said many drivers have had the habit of going 30 mph on city streets for so long before the speed limit changed, and that it can take time and effort to change behavior.

“You have to deliberately do something different to have it take hold,” Davis said. “It may be generations before a new batch of drivers who grew up with lower speeds is out there.”

Davis also noted that automated vehicles could lead to more compliance. “We’ll be watching,” he said.

Take transit to the polls

Election Day is Tuesday, and some metro area transit agencies are giving free rides to the polls.

Plymouth Metrolink will shuttle voters to polling locations within city boundaries from 6 a.m. to 8:30 p.m. through its Click-and-Ride on-demand ride service. Pickups can be scheduled at plymouthmn.gov/click-and-ride or by calling 763-559-5057.

Minnesota Valley Transit Authority is waiving fares for voters using its fixed-route or on-demand service, Connect, to get to the polls. Those booking rides on Connect can use the promo code VOTE2024 when using the RideMVTA app. Fixed-route riders can tell their drivers they are going to or from a polling site.

SouthWest Transit’s on-demand service, Prime, will take voters to the polls, but the last pickups will be at 6:25 p.m. To book a ride, call 952-797-7463 or use the SouthWest Prime app and enter code 2024POLLS arrange a free ride.

Neither Metro Transit nor Maple Grove Transit will provide free rides on Election Day.