road pricing 
noun [mass noun]
The practice of charging motorists to use busy roads at certain times, especially to relieve congestion in urban areas.That, at least in theory, might make increased charges to urban motorists that would accompany the introduction of road pricing easier to swallow....
- While this policy may work in some areas, traffic densities in most rural areas would make road pricing difficult to sustain.
- The notion that taxation might be used to adjust for externalities is gaining currency among policymakers for example, the ‘polluter pays’ principle and road pricing to reduce congestion.