The Safety Risks of Raising Speed Limits
Lawmakers in the United Kingdom are considering a plan to bump up the country's top speed limit from 70 miles per hour to 80 miles per hour by the beginning of next year. Public hearings on the idea are set to begin later this year. But two authors from the London School of Hygiene and Tropical Medicine argue that the idea will make roads less safe and bring about the deaths of many more people.
Writing in the British Medical Journal, Jamie Lopez Bernal and Martin McKee argue that the government’s reasoning for the suggested speed limit change is "shaky."
The U.K.’s Department for Transport claims that vast improvements have been made in automobile design, making them much safer at higher speeds. And, with roughly half of drivers already breaking the speed limit, bumping it up a bit would mean that “millions of otherwise law-abiding motorists would be brought back inside the boundary, restoring the moral legitimacy of the system.”
“[T]he Government believes safety cannot be the only consideration when setting speed limits. Previous analysis shows that raising the motorway speed limit would generate significant economic benefits, worth hundreds of millions of pounds per year from savings of travel time.”
The authors caution that ignoring the safety risks is short-sighted, and that the economic claims seem dubious. The problems associated with higher speed limits, they write, are numerous.
Research in several countries including the UK has shown an exponential increase in the number of crashes involving injuries and deaths with higher speed. However, the health consequences extend beyond road safety. They include greater emissions and consequent air pollution, and, potentially, rising levels of obesity as a result of increased car use among those taking advantage of shorter journey times.
The authors point to some evidence. When the maximum highway speed limit was raised from 65 mph to 70 mph and 75 mph in the U.S. in 1995, traffic-related deaths rose a reported 16.6 percent. They argue that a similar increase in traffic deaths could be expected if the U.K.'s speed limit is raised. And with more accidents on the roads, traffic would jam up more often. The lost opportunity cost of sitting in traffic would likely increase, as would the cost of healthcare resulting from the rise in injuries. Overall, they argue, it’s just a bad idea.
"It is difficult to see how any benefits of an 80mph speed limit would outweigh the costs.”
Photo credit: Susana Vera / Reuters