The London congestion charging scheme (CCS) was successfully implemented in February 2003 and has measurably reduced traffic flows in central London. The air pollution impact of the scheme has been difficult to assess using ambient measurements alone as the air pollution concentrations in 2003 were higher than in 2002 because of unusual meteorological conditions. However, a comprehensive analysis of the impact using detailed traffic data, combined with the Environmental Research Group’s road traffic emissions model, has identified a number of important results.

Atmospheric Environment 39 (2005) 167–177
Link to Journal: http://www.sciencedirect.com/science/journal/13522310