I cross a bridge for bikes and pedestrians and it is hit or miss if they decide to plow it. However, they have gotten better. Unfortunately the wind blows some of the snow back over the top.

On the parts of my commute with a bike lane I am usually closer to the road since they rarely ever plow it. The bike lanes are usually poorly maintained to begin with. Summer its broken glass and dead critters. Fall it is leaves and sticks. Winter their is snow and ice. Spring it is usually thawed garbage from the winter.