#109 Perhaps avoiding a left turn saves lives!

Also fuel

04.22.2023

Just like there are services like DTDC, BlueDart, DHL, there is a shipping service in the US called UPS and there’s something very interesting about how they operate. No. They do not claim to deliver your package in 10 minutes, yet! Neither do they offer crazy discounts on shipping. But what makes them interesting is that their delivery trucks (almost) never turn left! Yes. You read that right. But why?

The company says that by favoring right turns until unless a left turn is unavoidable, the shipping service saves millions of gallons of fuel each year, and avoids emissions equivalent to over 20,000 passenger cars. And this is done using their in house software that finds the most efficient route so as to avoid left turns. This may sound funny and weird at first, how taking the longer route by taking a right instead of taking a straight left can save gallons of fuel, but having been in the US for the past one year and driven multiple times, I can relate with the logic.

This is a good explainer on how taking a left turn works in countries following right-hand driving. Left-hand turns are generally considered unsafe and wasteful on right-hand driving roads, such as those in the US. While taking a left turn, one has to generally deal with the flow of oncoming vehicles and find a particular window to turn when no vehicle is coming straight towards you from the opposite direction. The roads often have a dedicated left turn lane, although it helps manage the traffic to a significant level, but adds 30-45 seconds to everyone’s time taking a left. Also a study shows that turning left is one of the leading “critical pre-crash events”, 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.

UPS says that left turns consume a lot of fuel because your vehicle is idling longer and is not good for the economy of the vehicle. Although the company does not reject a left turn outrightly, it makes left hand turns, but not ones that are unnecessary. A UPS truck doesn't need to go in circles all day long by making only right hand turns. They have tools that analyze the number of left hand turns for each route, and can work out which ones are avoidable. They have an in house maps software that is efficient in avoiding left hand turns unlike the commercially available ones. Google Maps and Apple Maps tell us the most direct route to the destination, while the UPS software tells the truck an efficient route by avoiding left turns.

“A lot of individual drivers felt the new routing software was making their trips longer, but they were later proven wrong. This is the thing about traffic, it’s such a complex system that often the individual cannot get a sense of the overall efficiency of the system, and optimize accordingly. It’s also one of the counterintuitive, ‘slower-is-faster’ effects you often see in traffic. In 2008, it launched a routing software to calculate the best possible route for each truck while favoring right-hand turns, called Orion: “It took 10 years to get it right. The hardest part was making it think more like a driver and less like a computer,” said Levis.”

Should we do it too?

The approach is effective when it comes to scheduled deliveries, but in everyday driving, our paths are usually less unpredictable. Many of us don't go to various locations, but we have to find ways to optimize our daily commute, which may have remained the same for years. Hence, avoiding left turns may not always be feasible in our more fixed daily travel routes.

See you next Saturday, Until then, have a great time :)

Cheers!

---

What’s cooking on twitter?

---