Energy & Sustainability
News From The Future: The End Of The Left Turn

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News From The Future: The End Of The Left Turn

“Every highway intersection is obsolete,” thundered Norman Bel Geddes—the designer and showman perhaps most noted for the Futurama exhibit at the 1939 World’s Fair—in his 1940 tract Magic Motorways. “The intersection is the chief stumbling block for highway designers and the chief headache for the traffic police,” he noted. “Why should the crossroads most heavily traveled today be the ones that are least adapted to the safe flow of the vehicles that use them?”

The question resonates today. In 2007, for example, the Federal Highway Administration reported there were 2.4 million crashes at intersections, representing 40 percent of all crashes, and one-fifth of all fatal crashes. Most intersection crashes fall under the category of “crossing paths,” and the most common path-crossing crashes, according to federal statistics, involve left turns.

UPS did something like this awhile back

Not so long ago, UPS drivers worked off maps, 3-x-5 note cards, and their own memory to figure out the best way to run their routes. That changed in 2005 when UPS began to implement a $600 million route optimization system–think MapQuest on steroids–that each evening maps out the next day’s schedule for the majority of its 56,000 drivers. So sophisticated is the software that it designs each route to minimize the number of left turns, thus reducing the time and gas that drivers waste idling at stoplights.

Between optimization, new design and even things like our in-car/phone GPSes limiting left turns we might not need as many left turns…

20 thoughts on “News From The Future: The End Of The Left Turn

      1. Well, with road modifications to reduce left turns, you’re spending taxpayer money on that, when there’s a road quality issue.

        Never mind that the reduced accident rate and reduced fuel consumption will mean that there’s more money available to spend on repairing the roads, too…

      2. I agree that they should work towards eliminating left turns.  But to me that’s secondary to making sure the roads are safe to drive on.

  1. :Having just arrived in Ireland from the US (I live in Ohio, but work for a company based in Dublin, Ireland) to participate in a longer term project, I have to sing the praises of roundabouts. I had a small amount of experience with them in Boston in the 70s and I know of one roundabout in Cleveland, OH that works, but confuses people because they haven’t seen them before.
    Here in Ireland, nearly every  intersection is a roundabout, at least where I am. Traffic flows smoothly, there are few delays, it is easy to slip into the flow of traffic and get to your road, even when the road is the one you were on going the other way (yes, I get lost, regularly). And this is even in light of the fact that this is my first week driving on the left hand side of the road. The retro fit would be huge, but what a benefit if the US could move in this direction.

    1. I don’t think roundabouts work as well with extremely high traffic volumes common most places in the US. I grew up in europe with tons of roundabouts, but living in the US now there is one roundabout around here where I can sit for 5-10 min while cars stream through. Since there is no gap in the traffic I can’t get in

  2. Heath, OH is tearing up their main drag through town, removing the center turn lane, and adding in a bunch of Michigan lefts (although controlled by lights, they’re not usually controlled by lights up in Michigan).

    A Michigan left is, essentially, passing your destination, and then doing a U-turn.

  3.  I work for a civil engineering firm and got to design a double diamond cross-over as shown in the picture.  Seeing an overhead animation of how they function, it’s amazing more aren’t used.  They are great for interchanges or where two heavy traffic roads intersect.  Sadly, since it’s not a standard design it’s a multi-year approval process with the state DOT.

  4. When it comes to plain old rational thinking, the Spaniards have been using a good solution for a long time. When a road offers the option of turning left, there is a small loop going off to the right. This loop places the automobile in a situation where it must drive straight ahead over the intersection. The driver is able to look right and left, making the situation less dangerous.

    1. This is typical at major intersections in the state of NJ. It takes a little getting used to remembering to get in the right lane so you don’t miss the turn, but otherwise, keeps the flow of traffic going on the main road.

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