A blast of winter meant a busy day for city crews Thursday, as they sanded and salted huge swaths of Winnipeg including icy bridges.

But there's a new item on the winter storm to-do list that's still being completed, thanks to a change in the city's traffic lights.

"Traffic signal lights at some intersections throughout the city ... have become partially obscured by snow frozen to the lens," Winnipeg manager of corporate communications David Driedger wrote in an email Saturday.

"Over the years, the city has replaced traffic signal bulbs with LED bulbs which are not as hot and do not melt the snow as the previous bulbs did."

Since Thursday, crews have prioritized lights at high-speed intersections from the southbound direction for clean up, since the winds came from the north, the city notes. The work was continuing Saturday.

If you come to an intersection but the lights are obscured, or partially obscured, by snow, officials say you should slow down and — if necessary — treat the intersection like a four-way stop.

Last year, new LED bulbs in Windsor, Ont., were blamed for a crash when a school bus ran a red light and broad-sided a car in an intersection. Six kids, a school staff member and the drivers of the car and bus were taken to hospital. Police said the bus driver claimed the red light was covered in snow.

Southern Manitoba saw a blast of winter late Wednesday and through Thursday, including wicked winds, a drop in temperatures and a mix of rain and snow.

Winnipeg police say the weather conditions resulted in crashes involving 97 vehicles at 15 different locations across the city, including on 14 different bridges. While no one was seriously hurt, nine people — including two infants — were taken to hospital in stable condition, while "countless" others declined medical attention for minor injuries, police said.