Amidst all the talk of ABS, ESC, and smart headlights that follow curving roads comes a reminder of a simpler in-car safety device: Passengers.

As Chris Lee and Mohamed Abdel-Aty, in the civil engineering departments of the University of Windsor and the University of Central Florida, respectively, report in a paper forthcoming in Accident Analysis & Prevention, drivers who had passengers in their cars were less likely to be involved in a crash.

They reached this conclusion after studying five years’ worth of crash data, linked to inductive loop readings, for a stretch of Interstate 4 in Orlando, Florida, picking out random involved drivers from crashes. Among 2817 crashes, 62% drove alone and 38% carried passengers (I know you’re thinking that more people drive alone so why wouldn’t there more be crashes by single drivers, but as a way to estimate exposure they used the sample of non-cited drivers). There’s all sorts of interesting observations here (drivers who were alcohol-impaired tended not to have passengers), drivers who had passengers seemed to wear seat-belts more often, and also that crashes tended to be less severe among cars having passengers (which may indicate a heightened sense of caution due to the responsibility of having other people in the car; they do caution they’re unable to state the speed of other crash-involved vehicles not chosen in sampling).

The argument has been raised that passengers serve as a distraction for drivers, but these findings add further evidence to the pro-passenger side: Passengers not only act as a second set of eyes, they help keep us awake, provide feedback to potential safety gaps in our own driving (what you might call a ‘backseat driver’), and may increase our sense of responsibility on the road. All these seemingly balance out or overcome the potential distractions they may cause.

The big exception here, of course, is teens, whose crash risk tends to increase with each passenger of a similar age.

This entry was posted on Monday, July 28th, 2008 at 2:28 pm and is filed under Drivers, Risk, Traffic Psychology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.