MnDOT study recommends speed increase on more than 5,000 miles of highway
Posted speed limits will be going up on more than 5,000 miles of state highway around Minnesota, the Minnesota Department of Transportation announced this week. The increase from 55 miles per hour to 60 miles per hour comes on the recommendation of a five-year study conducted by MnDOT.
MnDOT said most of the new speed limit signs are in place, and the rest are expected to be up by spring. Area residents first heard news of the change in November, when MnDOT District 8 announced speed limit increases on parts of nearly a dozen highways. District 8 includes several counties in southwest Minnesota, reaching from Pipestone County to Kandiyohi County. In the Marshall area, the list of speed limit increases included U.S. Highway 14, Minnesota Highway 19, and U.S. Highway 59.
The $1.2 million speed study was mandated by the Minnesota Legislature in 2014. Nathan Drews, engineering specialist in the MnDOT Office of Traffic Engineering, said it’s the agency’s most comprehensive study, in terms of detail and the miles of road studied.
A total of 7,000 miles of two-lane roadways were included in the study. Of that total, 5,240 miles were recommended for a speed limit increase. That amount accounts for 77 percent of the two-lane state highway system, the MnDOT report said. When all of the speed limit signs are installed, 81 percent of the two-lane state highways in Minnesota will have a 60 mile per hour speed limit.
The recommendation for speed limit increases on each road considered factors like highway access points, shoulder width, crash history, and the speed that 85 percent of motorists drive at or below, the report said.
MnDOT studied vehicle speeds on roads around the state both before and after their speed limits were increased. The study found that travel speeds on the sampled roads were slightly more consistent after the speed limit change, Drews said. The average speed of all drivers went up by one mile per hour, to 60 miles per hour. At the same time, the standard deviation, which measures how spread out the drivers’ speeds were, went down slightly.
“In other words, more drivers traveled at a similar speed after speed limits increased,” Drews said. “This is a desirable outcome, but this change is very slight and may not affect the frequency or severity of crashes.”
Some of the speed limit increases affecting area highways go beyond District 8. The speed limit on Highway 14 is now 60 miles an hour all the way from the South Dakota border to New Ulm. On Highway 19, the speed limit was increased from the South Dakota border to Gaylord. The speed limit on Minnesota Highway 30 was raised from the South Dakota border to Westbrook. The speed limit on Minnesota Highway 68 was raised between Taunton and Wabasso.