How cell phones cause traffic jams
Cars braking up ahead and full roads were recently pegged by mathematicians at the Universities of Exeter (in England), Bristol and Budapest, as two main causes of traffic jams. Reuters is reporting on research at the University of Utah's Traffic Lab that will add another item to the list: cell phones.
The reason that cell phones back up the highways is awful similar to why cars braking ahead does: little actions add up to big delays when the roads are full. The researchers conducted a study with 36 college students and ran them through a series of freeway scenarios. Reuters says that:
The drivers used a hands-free phone during half their trips and no phone in the other half. They were told to obey posted speed limits and use turn signals but the rest of the driving decisions were up to them. What they found is that when the drivers were distracted by a phone conversation, they made fewer lane changes, drove slower and took longer to get where they are going.
On average, people on cell phones finished the 9.2 mile courses between 15 and 19 seconds later than the\ drivers who were not distracted. Extrapolate this to the nation's highways, and we can see how each of those slowpokes on cell phones slows down traffic flow a little bit. With 10 percent of the drivers in the U.S. chatting while they drive, that adds up to a lot of 15- to 19- second delays. That means more time with the cars running and more gas wasted. So hey, hang up and drive greener.
[Source: Reuters]
Reader Comments (Page 1 of 1)
Kodos08 8:20PM (1/03/2008)
I have to disagree with your interpretation. Slower, cautious drivers do not necessarily lead to jams. And 15-19 sec longer trip does not necessarily lead to more gas consumed - especially in speeding or start-stopping traffic. What I interpret is that phones contribute to jams by distracting drivers into braking unnecessarily and failing to take advantage of lane-change opportunities that aid overall traffic flow.
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steven 10:02PM (1/03/2008)
@1: I have to disagree with your interpretation that people talking on the cell phone are cautious drivers. They need to turn the phone off and drive or get off the road.
It is not just driving slower, but driving while distracted. I drive slower now (60 mph) and I get to work (37 miles each way) at the same time I did when I drove faster (65mph-75mph), but get 10-12% better mileage and I'm a lot less pissed off when I get there, unless I end up dealing with some jerk talking on the phone while driving.
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scatter 6:05AM (1/04/2008)
Well I'm quite glad they drive slower really. Better than the alternative.
But also I'd suggest that running your car for longer periods doesn't necessarily mean higher emissions. If they're slowing down from, say 55 mph to about 45-50 mph they're going to be hitting pretty close to a vehicle's most efficient speed. However if they're causing traffic jams then that's another matter.
That's not to defend the practice though. The fact is that even if you're using hands free, you don't have 100% concentration on the road and that's dangerous.
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Whopper 9:22AM (1/04/2008)
When weather permits I ride my Sportster to work (48 mpg, 20 miles each way). About 16 miles each way is interstate highway. Driver inattention has caused me some very tense moments. Cell phones should be banned, hands free or not. A woman in an SUV using the rear view mirror to fix her makeup nearly put me in the guard rail. I actually passed a man in a Camry with a newspaper drapped over the steering wheel, glancing back and forth between the road and the paper!
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