Air pollution and transport policies at the city level. Module 2: policy perspectives

Recent research for EPHA, the European Public Health Alliance, has indicated that the average European citizen faces a welfare loss of over € 1,250 per year due to poor air quality. At present the transport sector contributes roughly 40-50% to overall NOx emissions and 10-15% to PM emissions. On average the current share of transport in ambient NO2 levels is estimated at 50%, but there are major differences among regions and cities.

This study reviews the impacts of transport-related policy measures in cities and how they affect air quality, focusing on five measures:

  • congestion charging
  • environmental (low-emission) zones (LEZ)
  • car-sharing schemes
  • parking policies
  • cycling/walking policies.

Based on a previous evaluation of social costs in 432 European cities in 2018, an estimate was made of the potential reduction of social costs due to these measures in 2020. It is concluded that Congestion charging and LEZ have the greatest potential to reduce transport PM and NOx emissions in cities. Reviews of cities that have implemented such measures indicate that a 10-20% emissions reduction is feasible. There are major uncertainties, though, as the effectiveness of measures depends largely on the stringency with which they are enforced and the size of the LEZ.

Parking policies can also be fairly effective, reducing PM and NOx emissions by 5-10%. Car sharing and Cycling/walking policies are far less effective in terms of PM and NOx emissions reduction, though particularly the latter has other benefits, such as improved health from active mobility and improved quality of city life if the space allocated to car traffic is simultaneously reduced.

The Initial costs of Congestion charging and LEZ are highest, although the costs of the former can largely be recovered from the fees collected. Cycling policies are costly if infrastructural changes are required, particularly in densely built city areas with limited space available.

These potential ‘savings’ in social costs may encourage local/city governments to implement such measures. This study’s findings indicate that, on their own, individual measures will have a rather limited impact: municipal governments aiming to reduce social costs should therefore consider rolling out several measures in combination.