At its meeting today (Jan. 26), the Wright County Board of Commissioners undertook an annual rite of passage – approving spring weight restrictions for vehicles during an eight-week period in the spring. Wright County Highway Engineer Virgil Hawkins said the purpose of the spring load restrictions is to protect the roads when they are their most vulnerable.
“This is an annual thing that we do,” Hawkins said. “It’s meant to protect the investments we’ve made in our highway system. During the spring thaw, the moisture content in the gravel under the pavement is really high and it weakens the pavement. So, every year we put restrictions on our highway system to preserve the life of our pavement.”
Hawkins said that a lot has changed with the Wright County road system in the 25 years he has been with the highway department. When he first started in Wright County, most of the roads had a 5- or 7-ton spring restrictions. But, as the system has been improved over the years, there are only three small segments with the 5-ton restriction remaining and almost all of the system has either a 9- or 10-ton spring restrictions.
Because spring weather is unpredictable and can vary greatly from one year to the next, the highway department seeks permission from the county board to approve the load restrictions in January.
“We ask for the permission to put on road restrictions at this time of year because when we’re going to put them on can vary by weather,” Hawkins said. “Most years they start in mid-March, but we’ve had a couple of years when they were put on in February because of warmer weather. When the restrictions are put on, they last for about eight weeks.”
Over the previous six years, there has been general consistency, but never two that were identical from the time the restrictions were in place – 2015 (March 12-May 7), 2016 (Feb. 29-April 15), 2017 (Feb. 21-April 17), 2018 (March 16-May 11), 2019 (March 19-May 14) and 2020 (March 9-May 4).
Typically, when the Minnesota Department of Transportation Central Zone announces its road restrictions, counties in that area follow suit. The roads are posted within 72 hours of the restrictions taking place, the county announces when the restrictions will begin and the Sheriff’s Office enforces those restrictions by weighing vehicles that may be over the posted limit.
The duration of the restrictions has as much to do with the cold of winter as the thaw of spring. In bitterly cold winters, the ground under roadways can freeze more than eight feet deep. Typically, the frost depth is five or six feet. The thaw makes roadways more pliable and subject to cracking, which is why the restrictions are so important to preserving the pavement and preventing damage to the roadways while they are the most vulnerable.
To see the 2021 weight restriction map, click here:
To see the Wright County Highway Department website page dealing with spring load restriction information, click here: http://www.co.wright.mn.us/904/Spring-Load-Restrictions