There's an art and science to winter road maintenance
The following was written by Public Works Director Jim Foldesi. It was originally published in the Hibbing Daily Tribune on March 7, 2018.
Have you ever noticed how much bigger your driveway or sidewalk suddenly seems when it’s covered in heavy, wet snow and needs to be shoveled? Now imagine you’re responsible for plowing and maintaining 3,000 miles of roads in the winter. That’s what we do at St. Louis County Public Works.
After a snow event, our priority is to restore all county-maintained roads to a passable condition within the shortest time possible. In case you’re wondering, 3,000 miles of roads is roughly the distance from Hibbing to the Mexican border AND BACK. And our goal is to plow that many miles within eight hours.
So how do we do it? Our winter road maintenance requires balancing many factors: first and foremost is safety; but also staff levels, vehicle availability and environmental protection all while staying within a limited budget.
There’s real science in our work as we determine when to apply de-icers, salt brine and salt/sand mixes, factoring in the weather, air temperature and road surface temperature. The most effective solution changes every day. And most likely even changes from route to route in our large county.
During events where it snows for an extended period of time, you are likely to see plows going down the road repeatedly, especially on busy streets. The reason for this is that scraping the road repeatedly during a snow event helps keep vehicles from compacting the snow on the road. This in turn minimizes the creation of icy spots on the road (a safety hazard) and the amount of chemical (salt) needed to melt the ice. If the temperature is too cold for salt to work, this becomes especially important. At intersections, vehicle exhaust along with snow compaction can very quickly create especially dangerous, slick conditions. This is also why you see plows less often on low traffic roads - less traffic means less compaction and associated creation of icy spots.
You’ll likely continue seeing our plows at work a day or two after the storm, but using different plow blades. Our trucks are equipped with a back wing blade to push snow off the road and back onto the far edge of the shoulder, slope or ditch. This is to prevent snow and ice buildup on the edge of the road that, when it melts, leads to water on the shoulder or road. This is an additional way of preventing ice on the road to maximize safety while minimizing use of salt.
St. Louis County Public Works is working hard to minimize the use of salt to melt ice because of the negative effects on the environment. Striving for continuous improvement, we will be expanding the use of brine. Today we pre-wet dry salt with equipment at the back of the truck before applying it to the road. Pre-wetting makes the salt stick to the road better so there’s less waste, plus it starts to work faster. Next plow season our crews will be out ahead of the storm to pretreat roads with anti-icing solution. This will further reduce our salt usage in a dramatic way, which saves money and also is good for the environment.
We continually seek to improve our winter road maintenance operations. We have a great crew working for us. In addition, the implementation of cutting edge technology – both within and on our vehicles and through the use of software to analyze a wealth of data, has helped us be more efficient and environmentally safe.
Winter road conditions are always a challenge. But if we all remember to be patient and slow down, we’ll get through it. Safely.
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