This report, from the international council on clean transportation, summarizes several actual and potential congestion-charging programs aimed in reducing motor-vehicle traffic: in-place systems in London, Singapore, and Stockholm; a 1980s pilot program and subsequent follow-on studies in Hong Kong; and a 2007 ICCT-sponsored study of Santa Clara County, California. The study notes many of the environmental and fiscal benefits such programs can produce, from a 15%–20% decrease in greenhouse gas emissions and reduction in fine particulates and other pollutants to generating revenues to support development of transit and other transportation system options. The range of technologies available to implement congestion-pricing systems is considerable and diverse. But public acceptance remains a hurdle, requiring effective leadership and communication.
Potential challenges and benefits are clearly described. Congestion charging need to be considered as a tool like parking price to increase constraint on single person in a car. Theses tools will progressivly become linked to create Pay As You Move system. But in the same time, authority need to propose alternative choice: several person in a car, public transport, and need to identify clearly who will still be simultanously car-dependant with low revenus without alternative.