Of course, we all know that cell phones used when driving are causing crashes to skyrocket, right? It’s such an epidemic that many states have started to make cell phone use behind the wheel a traffic offense, so it must be a problem, right? I mean, our government wouldn’t go creating problems that don’t exist just to pass more legislation, would they?
Initially, all indications were that the use of cell phones while driving had no real effect on accidents, injuries, or fatalities. In fact, it was shown that other more mundane activities such as changing the radio station were more dangerous. Well, now, finally, at long last, we have a comprehensive study of cell phone use and crash data (PDF) that, once and for all, shows…that there still isn’t any increased danger.
We investigate the causal link between cellular usage and crash rates by exploiting a natural experiment induced by a popular feature of cell phone plans in recent years—the discontinuity in marginal pricing at 9 pm on weekdays when plans transition from “peak” to “off-peak” pricing. We first document a jump in call volume of about 20-30% at “peak” to “off-peak” switching times for two large samples of callers from 2000-2001 and 2005. Using a double difference estimator which uses the era prior to price switching as a control (as well as weekends as a second control), we find no evidence for a rise in crashes after 9 pm on weekdays from 2002-2005. The 95% CI of the estimates rules out any increase in all crashes larger than .9% and any increase larger than 2.4% for fatal crashes…We confirm our results with three additional empirical approaches—we compare trends in cell phone ownership and crashes across areas of contiguous economic activity over time, investigate whether differences in urban versus rural crash rates mirror identified gaps in urban-rural cellular ownership, and finally estimate the impact of legislation banning driver cell phone use on crash rates. None of the additional analyses produces evidence for a positive link between cellular use and vehicle crashes.
In fact, they found that the crash rates fell over this period, by quite a lot. They also found that legislative bans on cell phone use reduced neither crashes nor fatalities.
But don’t go just casually blabbing because of this:
It should be noted, however, that our result is not inconsistent with the claim that cell phones are a source of attentional distraction. One possible explanation is that drivers compensate for the dangers of cell phone use by driving more carefully.
This a corollary to the Peltzman Effect, which deals with the effects of safety measures such as road signs and speed limits that I’ve blogged about in the past. Also, they found that, in general, people who talk on cell phones while driving are substituting the cell phone use for other distractions, and might even improve one’s driving by alleviating boredom.
As usual, don’t just go blindly accepting what politicians and pundits tell you. They’re more interested in taking your money and your liberty than they are in your safety.