Add street safety to the list of benefits from congestion pricing. That’s the takeaway from a new “working paper” analyzing traffic crash rates in and around the London congestion charging zone by three economists associated with the Management School at Lancaster University.
“Traffic Accidents and the London Congestion Charge” slices and dices the monthly changes in crash frequencies since the 2003 startup of London’s congestion charge in nearly every way imaginable: daytime vs. nighttime (the charge is in effect 7 a.m. – 6:30 p.m.); weekdays vs. weekends (no charge during the latter); within both the 8-square-mile charging zone and each of two “spillover regions” two and four kilometers outside the zone; for charged and exempt road users; for fatal and serious injury crashes and all crashes; and vis-à-vis a control group of 20 other British urban areas. (The comparison group is necessary to control for declining crash rates throughout the U.K.)
The bottom line: Traffic crashes are significantly lower with congestion charging — by as much as 40 percent within the cordon zone. Crashes are down in the spillover regions as well; they declined not only for autos and trucks but for “uncharged” vehicles like taxis, buses, motorbikes and bicycles; and the improvement registered during non-charge times as well as the hours when the congestion charge is collected.
Here are key findings:
- Traffic crashes within the charging zone are down by approximately 400 per year, relative to ongoing trends, corresponding to a 38-40 percent decrease — a reduction several times greater than the drop in vehicle miles traveled.
- Within both spillover zones, crashes are 13-14 percent less than in the control cities, belying fears that rerouting of journeys and/or destinations would merely relocate traffic conflict and danger to areas outside the zone.
- Even with considerable mode-shifting from cars to bicycles, motorcycles and taxis, crash rates for “uncharged” vehicles within the zone are 12 percent below those for the same vehicle classes in the control cities.
- Crash rates inside the zone during non-charge hours are also significantly less than in the control cities, i.e., gains in safety haven’t been confined to the 55-60 hours a week in which congestion is charged but are spread across all 168 hours per week.
- The congestion charge has led to an estimated 46 fewer serious and fatal crashes within the charging zone each year, including 4-5 fewer fatalities per year.