For high volume urban and local streets, the experts say we should return to the old standard of 10 foot width and no more. We’ve crept up over the years to 11 and 12 foot lanes with the belief that wider lanes are safer. But, the are not! Relax, high speed roads can still be 12 feet wide because we expect people to drive above the posted speed (nominally 70 MPH) and the wider lanes account for that. On city streets, however, drivers tend to ignore the posted speeds and drive at what they see as a safe speed. However, you have more pedestrians and bikes in the city and the pedestrians have further to walk to clear traffic and the bikes don’t fit. And, with higher speed on wider lanes, pedestrian death rates climb dramatically because 30 MPH is 7 times more deadly than 20 MPH if you’re hit. There is lots more on this topic in the Atlantic CityLab article at http://tinyurl.com/zbgh2jk You will also find references in the piece to other articles on the topic. The image accompanies an article by Jeff Speck on John Rosenbarger's 12-ft wide Spring Street traffic lanes: “A 12-foot lane is a 70 mph lane" says Speck.
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