The Minnesota Department of Transportation last year raised the speed limit on the Crosstown Hwy. 62 through Minneapolis, Edina and Richfield from 55 mph to 60 mph.

The agency did the same thing in the late 2010s on Hwy. 169 after the Nine Mile Creek Bridge in Edina was rebuilt and the road was resurfaced through St. Louis Park, New Hope and Plymouth.

On Hwy. 100, the speed limit increased from 55 mph to 60 mph south of I-394 after extensive reconstruction in 2016 added lanes and a fresh coat of asphalt. The move created a uniform speed limit between I-494 in Bloomington and I-694 in Brooklyn Center.

Last year MnDOT also set the speed limit on I-394 from Minneapolis through the western suburbs at 60 mph, up from 55 mph.

All those changes led Drive readers John and JP to ask about the 55 mph speed limit on I-35W through south Minneapolis, since MnDOT rebuilt the road and the freeway now has more lanes than the Crosstown, Hwy. 100 and Hwy. 169.

"I've noticed recently that speed limits on many metro freeways within the I-494/694 loop have been increased to 60 mph," John wrote in an email to the Drive. "But, the stretch of I-35W between I-494 and I-94 in the south metro is still 55 mph. Can you find out what the reasoning for that is?

Before any speed limit adjustments can be made, the agency must conduct a speed study, said MnDOT spokesperson Anne Meyer.

"MnDOT has not done a speed study on the I-35W corridor between I-494 and downtown Minneapolis yet, but we plan to in the fall of 2023," she said.

Speed limits on the Crosstown and on Hwys. 100 and 169 were modified after MnDOT conducted speed studies on those corridors.

MnDOT does speed studies on state highways and local roads to determine safe and reasonable speed limits. The studies look at how fast drivers travel in a specific corridor during uncongested periods and in areas free from curves, stop signs, traffic signals and entrance points.

"We will consider additional factors like roadway features — again curves, ramps — traffic flow and crash history to determine the appropriate posted speed limit," she said.

The agency looks at the "85th percentile speed." If the 85th percentile speed on a road with a posted speed limit of 60 mph is 64.3mph, 85% of drivers are traveling at or below 64.3 mph. The metric best shows the operational speed at which a majority of drivers travel on a specific roadway type, the agency said.

Road work ahead

A short but heavily traveled section of Hwy. 55 — also signed as Olson Memorial Hwy. — in Minneapolis will close for six weeks starting at 7 a.m. Tuesday.

MnDOT will shut down the highway between Van White Memorial Boulevard and Lyndale Avenue to remove an old tunnel that once carried Bassett Creek under the road, improve drainage and utilities, and resurface the highway.