Did Congestion Charges Affect Traffic Accidents in London?

Congestion Traffic Accidents and the London Charge (Colin P. Green, John. S. Heywood and Maria Navarro, Economics Working Paper Series 2014/015, Lancaster University Management School, Nov. 3, 2014)

 Also discussed here: London’s congestion charge increases speed and saves lives (Colin Green, The Conversation, Nov. 3, 2014)

Today we review research into the link, if any, between London’s Congestion Charge Zone (CCZ) introduced in 2003 and the number of traffic accidents in and around the zone. The CCZ has been successful in reducing the volume of vehicles entering the CCZ and increasing their speed, as a result of less congestion and increasing the number of public transit buses and bicycles. One might have expected accidents with cyclists and pedestrians to spike. However, research shows that accidents are down by 40% which translates into 45 fewer cases of serious accidents or death. Each increase of the congestion charge by a pound has decreased the number of accidents by 5 per month- and the effect also applies in surrounding areas and during times when there is no charge within the CCZ. As one commentator to the article pointed out, the impact may not be simply economics and that some credit may be due to the improved safety plan for the CCZ which included improved signaling and the simple fact that fewer cars means fewer accidents. The results indicate an unexpected benefit of congestion charging beyond improved air quality, more reliable travel and revenue for improved transit.

 Key Quotes:

“Traffic accidents and related injuries and fatalities weren’t the main target of the congestion charge, but they may have been influenced by it”

“The congestion charge reduced traffic accidents in central London by 30 a month – an enormous 40% reduction. Accidents that result in individuals being killed or seriously injured also fell, by just under four a month, or 45 a year. This means around 500 people have avoided serious injury or death thanks to the congestion charge.”

“Did the congestion zone just move traffic to other parts of London, other times of the day, or to non-charged vehicles?... The charge decreased accidents dramatically in the surrounding areas – about 20 fewer total accidents a month, with 3.5 fewer serious or fatal accidents. Our estimates also show that accidents and injuries were reduced in non-charged times (before 7 am and after 6 pm) and for exempt vehicles (largely bicycles, motorcycles, taxis and buses).”

"Is the congestion charge set at the right level?.. Since the initial £5 charge in 2003, it has been raised twice, £8 in 2005 and £10 in 2011…each pound increase in levy reduces accidents by 5 per month”

 “Implementing the Congestion Charge scheme involved a lot of junction redesign, improved signalling for all road users, roadspace reallocation away from cars; enforcement of bus lanes and other traffic regulations it was a comprehensive intervention, and also took place alongside, and closely co-operated with, delivery of a comprehensive safety plan.”

“While we have focused on only one benefit from the charge, accident reduction, other benefits include increased speed, travel reliability and reduced air pollution.”