This document summarizes a study that will test whether constructing a road tunnel at a migratory crossing used by common toads will decrease road mortality. The study will use a Before-After-Control-Impact design with data collected daily for 5 years at 6 roads during migration seasons. Control sites will be similar roads without tunnels. Volunteers will map roadkill locations using GPS. If tunnels reduce mortality, more may be constructed to help declining toad populations.