Talk Acclimation of drivers to a Roadside Animal Detection System

Roadside Animal Detection Systems (RADS) attempt to reduce the frequency of wildlife-vehicle collisions by sensing animals near the road and warning drivers with flashing signs. We evaluated a RADS built on U.S. Highway 41 in Florida, U.S.A.

Objective: Our previous study using a driving simulator showed that a virtual RADS reduced driver speed, so we wanted to assess how effective the system is in real life. We also wanted to test the effects of potential driver acclimation to the RADS.

Methods: To assess driver response to the RADS, we measured the speed of individual cars on U.S. Highway 41 when the RADS was active (flashing) and inactive (not flashing) during four periods over the course of a year. This allowed us to test for differences in driver behavior between the tourist season (mostly non-local traffic) and the off-season (mostly local traffic). We expected that locals may have become acclimated to the RADS.

Results: In the tourist season, but not in the off-season, the activation of the RADS caused a significant reduction in vehicle speed (3.81 km/h). There was also a significant interaction between season and time of day. During the tourist season, drivers drove faster (5.54 km/h) at twilight than at night. The same effect was observed in the off-season, though the difference was not as large (3.15 km/h). The overwhelming factor influencing speed was time of day.

Conclusions: Despite the fact that drivers in the tourist season generally drove faster than those in the off-season, tourist-season drivers responded to the RADS by reducing their speed, while off-season drivers did not. We suggest that this result is from acclimation by local drivers to the RADS, especially because it often malfunctioned and gave warnings when no animal was present. If the system functioned properly, this acclimation may not have occurred.

Contributions to Practice: Our study is one of the longest field studies of a RADS and the first to test the responses of potentially acclimated drivers (locals) against those of non-acclimated drivers (tourists).

mitigation; road ecology; RADS; transportation; vehicle