Mobile Phones Lengthen Commutes

The problem with mobile phones isn’t simply that distracted drivers pose a collision danger (although they do!). More often than not, telephoning drivers are just plain slow, too. A recent study from the University of Utah shows that drivers who are on the phone — even with a hands-free device — drive about two miles per hour slower than drivers who are not on the phone.

The study put three dozen students in simulators and found that drivers on mobile phones are more likely to stick behind a slower vehicle, and that they change lanes about 20% less often than drivers who are not on the phone. Drivers who were on the phone took about 3% longer to drive a highly congested route, and about 2% longer to drive a moderately congested route, than did attentive drivers. Combining all factors, study author David Strayer figures that distracted drivers add an extra 5% to 10% to commuters’ travel times.