Sustainable transportation is about 'bridging the gap' between humans, the environments we create, and the natural world around us.  Roads that cut through prime wildlife habitat can have design features that minimize the negative impacts.

Below is a profile of a context-sensitive design for Highway 93 in the Flathead Valley of Montana.
This highway is touted as one of the most wildlife-friendly highways ever built in the United States. There are 43 animal crossings in this 70-mile section that are either built or planned.

A key to this happening was the Salish and Kootenai Indians negotiating a design that would protect their culture. (map from Ken Barnedt of the Missoulian).