Two important issues that will need to be addressed as the world moves toward sustainable transportation systems are considered: access to public transportation, both urban and rural; and efforts to make the transport sector internalize its environmental costs. In Europe, acceptance is gaining for lowering fuel duty and introducing more specific polluter-pays mechanisms, such as a kilometer charge for the use of roads. Switzerland is cited as an example of a transport system characterized by a high share of public transport modes with respect to both passengers and goods. The problem of aviation is considered separately, due to its extremely fast growth, global aspects, and increasing constraints on the environment.