How many bees are killed by vehicles every day in Utah?

The growing interest in protecting pollinators, particularly native bees, has led to various conservation efforts to help save the bees. One of these efforts involves planing roadside pollinator habitat to provide forage for native bees. While these efforts may indeed increase pollinator friendly habitat, what effect might roadside habitat have on bee mortality due to collisions with automobiles? To estimate the number of bees killed by vehicles in Utah, I attached a glue trap to the front bumper of my car as I drove to various field locations in 2019-2021. I then counted the number of bees on the sticky trap and recorded the route and number of miles traveled. These data were then used, along with traffic data, to estimate the number of bees hit per day on Utah roadways. Bee mortality varied dramatically depending on the route traveled, but a somewhat conservative estimate is that over 200,000 bees are killed by vehicles every day in Utah throughout the spring and summer months. These data should be considered when planning roadside pollinator habitat.