The structure of a city—its urban form—shapes transportation networks for public transit, private vehicles and freight.

Schemes to regulate access to various parts of the city can be created by exploiting technology and applying principles of physics.

Typically, for non-commercial users, policy instruments include:

• variable, time-dependent traffic tolls that can change according to time and location,
• restrictions on vehicle access, and
• improved transit service to accommodate travelers who would have used cars.

For freight users, solutions include “green logistics” and sustainable service systems that:

• consolidate freight delivery on the periphery of cities and
• grant special access privileges to vehicles operating in those centers.