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Video Tip: Why UPS Drivers Don’t Turn Left And You Probably Shouldn’t Either

November 3, 2017

Vehicle routing problems involve finding the best route between points

It might seem strange, but UPS delivery vans don’t always take the shortest route between stops. The company gives each driver a specific route to follow and that includes a policy that drivers should never turn through oncoming traffic unless absolutely necessary. This means that routes are sometimes longer than they have to be. So, why do they do it?

Every day, along with thousands of other companies, UPS solves versions of the vehicle routing problem (see Online Tutorial 5). In these mathematical problems, you are given a set of points and the distances between them, and you have to find the best route(s) to travel through all of them. Best is usually defined as the route with the shortest overall distance. Vehicle routing problems are used to organize many things, from coping with more delivery trucks in cities and hailing taxis to catching chickens on a farm.

UPS has designed its vehicle routing software to eliminate as many left-hand turns as possible. Typically, only 10% of the turns are left turns. As a result, the company uses 10 million gallons less fuel, emits 20,000 tons less carbon dioxide and delivers 350,000 more packages every year. The efficiency of planning routes this way has even helped the firm cut the number of trucks it uses by 1,100, bringing down the company’s total distance travelled by 28.5 million miles – despite the longer routes. The TV series Mythbusters tested this idea and confirmed that, despite many more turns, the policy of only turning right does save fuel.

Here is an entertaining 1 minute video illustrating the point. You could show it when discussing sustainability (Supp.5) or process analysis (Ch.7).

2 Comments leave one →
  1. Gary Ragatz permalink
    November 3, 2017 2:32 am

    Hi Barry,

    Interesting post. I understand the right-turn vs. left-turn logic, and use it myself when I’m driving. But I’m curious about the results cited in your post – does UPS claim that these results come from just the right- vs. left-turn logic, or from more effective vehicle routing, in general?

    In particular, I’m thinking of the 28.5 million miles saved, in spite of some of the routes being longer (in miles) due to the preference for right-hand turns. I see how shorter (in time) routes would enable UPS to reduce the number of trucks by 1100, but it seems to me that the only savings (in miles) attributable to the right-turn/left-turn logic would be the miles those 1100 trucks would have traveled going from their origin to their first delivery point and the miles from their last delivery point back to origin (the miles from stop-to-stop still have to be traveled by another truck still on the road). For a reduction of 1100 trucks to generate 28.5 million miles saved, that would be nearly 30,000 miles per truck per year (and that doesn’t net out the additional miles the other trucks travel due to the right-turn preference).

    I’m wondering if UPS isn’t just claiming that better vehicle routing (not just the right-turn preference) has allowed them to reduce their fleet by 1100 vehicles, and their average vehicle travels ~ 30,000 miles per year?

  2. November 3, 2017 1:50 pm

    Gary, Good observation and I think you are 100% correct.

    I spotted the following quote: “I have nothing against left turns, it’s just amazing how our methods over the years continue to show it’s always better to have right turns,” said Mark Wallace, VP of U.S. Industrial Engineering at the company. “We do find places now that we see drivers that actually take some left turns because it optimizes the route, though they’re generally in more rural areas.”

    How does UPS know that right turns are better? The company built a proprietary GPS system called Orion. Instead of showing you different ways to get from point A to point B, taking into account traffic and tolls, ORION shows the best way to get from point A to Z and all the stops in between while also making specified delivery windows and getting you your packages before, say, 5pm. When ORION calculates the most efficient route, it almost never routes a left turn.

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