Sharing a border, roads and thousands of residents passing in between, Wisconsin and Minnesota often experience similar weather in the winter, and similar road conditions.
The Wisconsin DOT has 770 trucks plowing its 34,339 lane miles, and the Minnesota DOT puts out 843 snowplows for its 30,517 lane miles. Lane miles are the preferred measurement term as plows have to cover every lane of a road. This means 10 miles of a two-lane road would be 20 lane miles.
Though some techniques are the same, how the two states manage their response differs.
Wisconsin is the only state in the country that gives winter maintenance of stage highways from the DOT to individual counties.
"We do maintain the state's system as well as the county system," said St. Croix Highway Commissioner Robbie Krejci.
Local counties maintain the state roads with their own staff and equipment on hand, but WisDOT pays for the costs of labor, equipment and materials for those routes.
WisDOT also sets some guidelines for the counties, including how to categorize state highways. These roads are assigned a category from one to five based on traffic volume. Category one highways are major urban roads with six lanes or more, while category five roads are two-lane highways with less traffic. The higher volume category ones receive 24-hour coverage during winter storms, meaning the roads receive attention for the full day of the storm, down to 18-hour coverage for category fives.
Actual operation is left in the hands of the local county highway departments.
St. Croix County
St. Croix County operates 46 snowplows to cover 2,400 lane miles of state, county and local roads.
In addition to the county and state systems, St. Croix County also plows for 16 out of its 21 townships. Municipalities like city of Hudson, River Falls and New Richmond have their own plow systems for city streets.
Currently St. Croix does do some pre-storm preparation including anti-icing.
"It buys time," Krejci said.
The county has limited facilities at the moment, but Krejci said the new county highway facility, which is planned to open in 2019, will allow them to do more preparation with techniques like liquid application.
In addition to its central facility in Hammond, the county has facilities in Hudson, Somerset, Deer Park and Glenwood City, as well as salt storage in Cady and Houlton.
When the storm hits, Krejci said the county staff uses best management practices from WisDOT. Though plans are in place for generally how to respond, Krejci said much of the response is storm-by-storm.
"The storm determines our response a lot of times," Krejci said.
St. Croix County has a few higher category roads with a high volume of traffic including Interstate 94, Highway 35 and 64 and the St. Croix Crossing Bridge. These are serviced as 24-hour service highways, meaning the county works on the roads in some way for 24 hours during the day of a storm until the road is clear.
"When you're driving to work in the morning, we've made a full round," Krejci said.
Of these roads, Krejci said I-94 and the St. Croix Crossing bridge both pose challenges. The county also has 18-hour coverage roads as well.
Krejci said putting the county in charge of state highways in the area is beneficial.
"We're here, we understand our system," he said.
It provides for better response time when it's controlled locally, he said. Snowplow operators have their own beats, or sections of roadway, that they cover every time, and they know them well. They know what areas are problems, the hills and corners or where drifting will occur.
"They become intimately familiar with those sections," Krejci said.
The county is also available as a backup for areas within the county that need extra help.
Pierce County covers almost 1,100 lane miles with 16 trucks. That's 370 miles of state highway, 500 of county highway and 222 miles from three townships in the county.
Preparing for a storm in Pierce County starts at the beginning of the year, making sure the county has enough salt, sand and brine, Highway Commissioner Chad Johnson said, and that the equipment is ready. When winter comes, the county makes sure trucks are loaded with salt or sand. The county uses anti-icing liquid on state highways, and salt brine on county and township roads.
Salt prices have risen recently, which is why the state is promoting the use of liquids more, Patrol Superintendent Al Thoner said. He said the brine used for the county is "cheap and foolproof."
"If they've got salt brine on they'll be just fine," he said.
Johnson said the county does pretreat roads where doing so would be beneficial.
Pierce County's state highways are category five roads, meaning they receive 18-hour coverage from 4 a.m. to 10 p.m. These two-lane highways are designated for less attention by WisDOT.
"We follow the WisDOT protocol on our county system," Johnson said. "We don't have the staff or budget to do 24-hour."
Johnson said that's why people may notice a difference traveling between Pierce County and St. Croix County, which has roads with higher categories.
"People like to use that county line to compare," Thoner said.
Cars driving on roads as snow falls can make plowing more difficult, as they sometimes pack snow down on roads before plows can get there.
"We're going to do all we can," Thoner said.
Ice events are another thing altogether. Thoner said the county uses salt to stay ahead of those types of storms.
"We can stay out 24 hours on an ice event," he said.
The Prescott bridge can be a trouble spot, with the route switching from ground road to the different setup of the bridge. When the local maintainers aren't plowing in the winter, they help work the Prescott lift bridge in the warmer months.
The hills in the county are a main trouble spot, Thoner said. The solid rock of the hill stays cold, which means ice will form.
"The maintainers know that that's one spot," Thoner said.
Both Thoner and Johnson said the local county maintenance is a benefit to both WisDOT and the county.
The Wisconsin method is fine—for Wisconsin, said Steve Lund, state maintenance engineer in the operations division at the Minnesota DOT.
"They seem to make it work," he said.
That system wouldn't work as well in Minnesota though.
"If we operated under the Wisconsin method we would have 87 districts," Lund said. "Each county would be a different entity."
Instead MnDOT divides the state into eight districts. Each district has a maintenance engineer to oversee and coordinate snow and ice response, including de-icing, plowing, and applying sand and salt.
Though they don't outsource the work to local control, the crews are local,and often live in the area. They know the roads and potential trouble spots, Lund said.
"They know their system better than we do in here (headquarters)," he said. ""From a corporate perspective we don't begin to tell them how to respond tactically but we do have a very strong corporate and statewide relationship in performance measures, setting and monitor the performance measures and reporting on those."
Dakota and Washington counties are in the Twin Cities Metro District, which also includes Anoka, Carver, Chisago, Hennepin, Ramsey and Scott counties. In this district, crews are responsible for clearing 1,095 miles of state highway, adding up to 4,076 lane miles.
"A mile of 494 might be one centerline mile but if it's two or three lanes in each direction, a centerline mile of 494 might be six lane miles," Lund said.
Last year, this area saw 43.5 inches of snow. Measurements are collected at the MSP International Airport.
MnDOT prioritizes its roads using five categories. They include supercommuter, urban commuter, rural commuter, primary collector and secondary collector. The most rapid response is afforded to the supercommuter roadways, the most heavily traveled routes. These include roads like Interstate 494 and Interstate 35W.
"They're all a priority so to speak, but on our supercommuters we might have multiple plows on the same routes and the plow routes might be shorter," Lund said. "But the secondary roads, they might have a single plow with a longer route."
MnDOT measures their efficiency in clearing roads by a "bare lane regain time." Generally, this means the elapsed time from the end of a winter storm to the removal of snow and ice from the surface. The bare pavement target supercommuter roadways is 0 to 3 hours. The bare line regain time for the least traveled secondary collector roads is 9 to 36 hours.
According to their 2016-17 report, MnDOT exceeded its overall performance target of 70 percent bare lane targets.
Staff writer William Loeffler contributed to this story.