Since then, Central London has become an international poster child for the economist's dream solution to traffic woes: congestion pricing. In 2003, the city began charging private and commercial vehicles to enter the area during weekdays, a strategy that has dramatically curbed traffic and pollution there. It now turns out that the tactic has yielded yet another host of benefits: Even as traffic has sped up, the roads in Central London have become far safer.
Crashes — including fatal ones — have declined significantly, according to new research from Colin Green, John Heywood and Maria Navarro at the Lancaster University Management School, to be presented later this month at the Royal Economic Society’s annual conference. The result isn't simply a product of having fewer cars on the road. The probability that each car traveling there will now get in a crash has declined, too. The number of crashes per million miles traveled, in short, has plummeted.
In total, the researchers conclude that congestion pricing in Central London has been associated with 30 fewer crashes a month in the area, a drop of about 40 percent. Meanwhile, they estimate that the policy has led to about 46 fewer serious and fatal collisions a year — and 4.6 fewer deaths.
This wasn't an obvious result when the city began this experiment a decade ago. Buses, taxis, motorcycles and bikes are exempt from the charge, which now costs £10 a day (it's enforced through a series of video cameras and license plate readers). It's possible that any safety gains from having fewer cars on the road might have been wiped out by other changes created by the policy — if, for instance, faster travel turned fender-benders into major crashes, or if more taxis and bikes flooded the roads, or if cars simply changed when and where they drive to skirt the congestion fee.
This data, though, which compares central London to changes in traffic patterns in other U.K. cities over the same time, found that crashes declined even on the periphery of the congestion zone and for all kinds of vehicles. Because cycling initially surged in the area after 2003, cycling accidents increased at first. Over time, though, crashes and fatalities involving cyclists declined, too, consistent with other evidence that cycling grows safer the more people who do it.
All of this data adds a powerful new argument to why more cities should seriously consider congestion pricing. Yes, it's politically unpopular, but it works — it encourages people to drive less and use public transit more (while generating millions to invest in transit). Yes, it's politically unpopular, but it makes economic sense — it causes people who do drive to pay costs for the congestion and pollution they create. And it saves lives. As more cities are now embracing "vision zero" campaigns to end traffic fatalities, congestion pricing starts to look like one potential solution to that problem, too.
Few cities have really considered following London's lead. Micheal Bloomberg was quickly shot down in New York City when he proposed congestion pricing there. So it still feels like a long shot in the U.S. But if you're a fan of the fringe idea, add this argument to your sales pitch.