County crash map review highlights state-highway concentrations; team to share maps with municipalities

Washington County staff reviewed countywide crash maps and a county-highway-system map at the Public Works Committee meeting, identifying concentrations of crashes in urbanized areas and along state highways.

Staff credited GIS analyst Mike Vander Sandman and said the crash data came from the Traffic Operations Safety Lab (TOPSLAB) at UW–Madison. The maps use a recent five-year window (2020–2024) and include visual distinctions for property-damage-only crashes versus injury and fatal crashes; staff said fatalities tend to appear more in rural areas and certain freeway locations.

Committee members discussed specific corridors with apparent crash concentrations, for example Highway K and 41 near a freeway interchange; staff noted some high-severity crashes were related to extreme speeding incidents rather than roadway geometry. Staff said many sites with higher crash counts have already received treatments and that the maps sometimes reflect pre-improvement data. The county will produce municipal-level maps for each local government to support local intersection and roadway safety planning, and will host a roadway transportation discussion with local governments on April 16 to review these maps and related intersection plans.

Staff emphasized the maps are tools for prioritizing locations for safety interventions, with the goal of reducing fatalities and injuries first. The committee praised the work and discussed next steps for coordination with towns and villages.