Why UPS trucks (almost) never turn left - CNN
▻http://edition.cnn.com/2017/02/16/world/ups-trucks-no-left-turns/index.html
(article de février 2017)
What’s wrong with turning left?
Left-hand turns are generally considered unsafe and wasteful on right-hand driving roads, such as those in the US.
“Left-turning traffic typically has to turn against a flow of oncoming vehicles,” explains Tom Vanderbilt, author of the book “Traffic: Why we drive the way we do.”
“This can not only be dangerous, but makes traffic build up, unless you install a dedicated left-turn ’phase,’ which is fine but basically adds 30 or 45 seconds to everyone else’s single time,” he said.
A study on crash factors in intersection-related accidents from the US National Highway Traffic Safety Association shows that turning left is one of the leading “critical pre-crash events” (an event that made a collision inevitable), occurring in 22.2 percent of crashes, as opposed to 1.2 percent for right turns. About 61 percent of crashes that occur while turning or crossing an intersection involve left turns, as opposed to just 3.1 percent involving right turns.
Left turns are also three times more likely to kill pedestrians than right ones, according to data collected by New York City’s transportation planners.
The right way to save fuel
“A left-hand turn is also less fuel efficient,” said Jack Levis, UPS Senior Director of Process Management, “because your car’s idling longer, which is also not good for your vehicle.”
UPS does not ban left turns outright, says Levis: “We will make left hand turns, but not ones that are unnecessary. We don’t need to go in circles all day long by making only right hand turns. We have tools analyze the number of left hand turns for each route, and we can work out which ones are avoidable.”
The procedure is now incorporated in most countries around the world.
