Animals don’t understand roads and cars like humans do. To an animal, running across a road is no different than running in a field or forest, except it’s harder and smoother. In areas where there are a lot of development of previously natural areas – think new housing developments being built on the edge of suburban areas – animals aren’t used to fast cars driving along roads. However, in areas where there are natural areas in regions of mature development, animals become aware of human activity and understand that things like cars are dangerous.