Toad tunnels beneath roads allow safe crossing during spring migrations; monitoring their use is essential to evaluate and improve effectiveness.
Road mortality is a direct and significant welfare harm to individual toads: vehicles cause crushing injuries and death. Toad tunnels provide a welfare solution at landscape scale by separating migration routes from traffic. Monitoring tunnel use ensures that installed infrastructure is actually functioning — a key step often missed. Data from monitoring informs design improvements for future installations and maintenance of existing structures.