When he was behind the wheel as a snowplow operator, Tyler Buerger wanted to know more about how salt application decisions were made. Now as assistant director of public works for the City of Oak Creek, Wisconsin, he has built a tool that could help determine optimal salt application rates on winter roads.
“Most of what we do at Oak Creek is proactive when it comes to winter maintenance, but how can we take it to the next step?” asked Buerger, who was looking for a way to apply data from available programs that gather pavement and forecast information.
When Buerger learned about the National Weather Service’s Winter Storm Severity Index (WSSI) at a training session in 2024, he immediately realized the possibilities. “It fit to a tee,” he said. “It fit what we could do with our data.”
Essentially a scale to help classify the intensity of a winter storm or event, the index assigns storms a numerical or categorical score based on various predetermined factors. The WSSI scores allow for comparisons of storms over time, which helps in preparing resources and communications about storm risk.
At first, Buerger tried several WSSI methods. He also consulted with Eric Faulkner, a meteorologist and weather advisor with Vaisala Xweather, who has helped maintenance professionals use new technology to increase efficiency. as well as with weather and road weather education.
Buerger and Faulkner talked about their efforts at the 2025 Salt Symposium. Hosted by Bolton & Menk, the August 5 event brought together professionals from throughout the world to share research, projects, and approaches for chloride management.
Faulkner suggested that Buerger build his own WSSI. To do so, Buerger first asked his supervisors to rate the importance of eight different categories that impact snow removal operations. Pavement grip led the ratings; precipitation rate, pavement temperature, and precipitation amount rounded out the top four, followed by storm duration, wind speed, air temperature, and storm type.
Buerger then weighted each category to further fine-tune the WSSI. He sought to verify the index’s accuracy by comparing two nearly identical storms, one in 2024 and one in 2025. The WSSI scores matched consistently with both events. Buerger also noticed a drop in salt use between the two events—from 71 tons in the 2024 event to 53 tons in the 2025 event and realized an unintended benefit. In addition to forecasting, he would be able to benchmark his team on salt use over time.
Currently, Buerger uses the WSSI after events for comparisons but looks forward to implementing it in operations for greater efficiency and even more precise salt application during winter events.
“Taking what the forecast is saying what we could have, I can now start pulling severity indexes close to what the forecast is and prepare my fleet, my guys, for what is coming,” he said.
The availability of data combined with artificial intelligence offers a powerful combination, with Buerger’s index helping demonstrate the potential of data-driven innovations, Faulkner said.
“At present, we’re seeing very mixed reactive/proactive approaches [across agencies],” he said. “We’re trying to move forward in future winter maintenance, with more automation, and a proactive type of operation.”
—Darlene Gorrill, contributing writer