It is important that authorities that decide to implement access restrictions have a vision for their urban mobility.
There are five main types of measures that restrict access to cities:
- Licenses or permits,
- Vehicle masses and dimensions,
- Vehicle emissions,
- Time restrictions and
- Charging mechanisms.
Each restriction method has its benefits and disadvantages. Success of an access restriction scheme depends on the details of how it is put into practice. It is a case of assessing each restriction measure on a case-by-case basis, in accordance with certain criteria, to establish whether or not they are effective in improving mobility in urban environments.
A number of cities have implemented access restrictions that charge in order to try to reduce congestion across Europe. These include London, Stockholm and Milan, which explicitly charge users with the express intent of discouraging vehicle use and ownership.