Best Practices: Vision Zero Lessons from London’s Congestion Pricing

But how congestion charging influences traffic crashes and related injuries and fatalities is, at least theoretically, not so simple. If the charge is successful in reducing congestion, and the evidence is that they are, fewer cars leads to an expectation of fewer traffic crashes. At the same time, reduced congestion means higher travel speeds. For example, prior to the introduction of the congestion charge in London, average vehicle speeds were just 8.6 miles per hour, and one-third of vehicle travel time during prime hours was spent simply not moving. Speed increases the chance of a crash and increases the severity of crashes that do occur This may be particularly dangerous in dense urban areas where cars, cyclists, and pedestrians share space. It was these issues that my research, joint with John Heywood of the University of Wisconsin at Milwaukee and Maria Navarro of Lancaster University, sought to examine, focusing on London.