Roads affect wildlife through direct mortality but also through effecting behavioural change. We explored the effects of unsurfaced vehicle roads on the travelling behavior of gopher tortoises (Gopherus polyphemus), using the footprint tracks left by tortoises as evidence of their travel decisions and movement patterns when confronted with vehicle tracks in sand within their habitat. Tortoises (and most other taxa leaving tracks on the roads) did not appear to make use of roads for travel but attempted to cross them directly, the success of which was influenced by the size of the individual: smaller animals (presumably younger tortoises) were more challenged than larger animals by both sand road widths and depths of vehicle ruts in sand roads. Sand roads may present both physical and physiological challenges to gopher tortoises, particularly to small ones. This research provided further evidence that the negative influence of roads in fragmenting the environment is not limited to vehicle mortality, and may be mediated by animal size.