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Skinny roads save lives. That's the verdict of a new study on the width of traffic lanes. NPR's Adam Bearne explains.
ADAM BEARNE, BYLINE: Researchers at the Johns Hopkins Bloomberg School of Public Health studied over a thousand streets across seven different U.S. cities in a quest to save lives.
SHIMA HAMIDI: We were just shocked by seeing the statistics about traffic fatalities in the U.S. being the leading cause of death for people with the age of 1 to 54.
BEARNE: Shima Hamidi is the study's principal investigator.
HAMIDI: And the main reason is the lack of pedestrian and cyclist infrastructure.
BEARNE: Her team wanted to know if traffic lanes could be narrowed to allow more room for that infrastructure, but that goes against traditional thinking that says wider roads are safer because they leave drivers more room for error.
HAMIDI: We found that wider is not better. Actually, wider streets have more crashes.
BEARNE: That's especially true of roads with 12-foot lanes and speed limits of 30 or 35 miles per hour. They had 1 1/2 times more crashes than roads with just 9-foot lanes and the same speed limit.
HAMIDI: The current practice of street design is to start with 11 or 12 foot and then have traffic engineers justify if it needs to be narrower. We are recommending that it should be reversed. They can start with 9 or 10 foot and have their traffic engineers justify why it should be wider.
BEARNE: Randy McCourt is a past president of the Institute of Transportation Engineers. He's worried about that recommendation when it comes to faster speed limits.
RANDY MCCOURT: It's a slam dunk on the 20 and 25, but when you get to the 35, 40, you got to be very careful.
BEARNE: McCourt says that's because drivers going that fast have so much to think about that it could make it tough to navigate a narrow lane safely.
(SOUNDBITE OF CAR ENGINE REVVING)
BEARNE: For Jessica Hart of the group Families for Safe Streets, narrower lanes make sense. Her 5-year-old daughter, Allie, was struck and killed by a driver while riding her bike in Washington, D.C., two years ago.
JESSICA HART: The report's findings really track what we and other safe streets advocates have been saying for a while, which is when you design streets so that cars can go more quickly, then you have far more crashes.
BEARNE: Hart's hoping traffic engineers leave a little more room for those who aren't driving.
Adam Bearne, NPR News.
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