UPS saved a lot of money by eliminating left turns from its delivery routes. Would this practice be effective on a larger scale? At Smithsonian, Sarah Zielinski writes:
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UPS minimizes left turns for its delivery trucks to save on fuel. (And it works, as the Mythbusters demonstrated last year.) In the 1960s, the state of Michigan designed an intersection known as the “Michigan left” that prevents people driving on side streets from making left turns onto a multi-laned divided road; if they wish to go left, they’ll first have to go right and then make a U-turn. And superstreets, or restricted crossing U-turns, which are found in some other parts of the country, such as North Carolina, work in a similar way, preventing left turns. It’s never really caught on, though, since it seems to be a big inconvenience.
However, a new study from North Carolina State University says that superstreets are actually more efficient than traditional intersections. The researchers collected data from three superstreets in North Carolina that had traffic lights and looked at travel time for both right and left turns as well as passing straight through. They also examined collision data from 13 superstreet intersections in that state that didn’t have traffic lights.
Link via Marginal Revolution | Photo by Flickr user taberandrew used under Creative Commons license
"Roundabouts are safer than both traffic circles and traditional junctions—having 40% fewer vehicle collisions, 80% fewer injuries and 90% fewer serious injuries and fatalities (according to a study[16] of a sampling of roundabouts in the United States, when compared with the junctions they replaced)." - http://en.wikipedia.org/wiki/Roundabout