It may not seem like it, but the process of delivering your LED tik tok lights is actually quite complex. Billions of packages are delivered every year across the country, and these numbers are only expected to rise. In order to keep up with this massive demand, delivery companies must maintain maximum efficiency in order to save time and resources. In the pursuit of this efficiency, one such company, UPS, has historically employed what, at first, may seem to be a strange strategy: never turning left.
The policy of minimizing left turns first came about in the 1970s with a system called “Loop Dispatch.” This is similar to a mathematical problem known as the travelling salesman problem which deals with visiting points in the most efficient path, then returning to your starting position. With each added point, the number of possible paths increases as a factorial function (ex. 4! = 4x3x2x1, these functions grow VERY fast). One statistical way to minimize the distance is by creating loops. UPS truck drivers would organize their package delivery routes in these ‘loops’ starting with the right side streets then the left. In essence, it worked similar to only turning right in a maze: you are able to efficiently cover all the ground without backtracking. Not every single route would be shorter, but statistically it evened out to overall shorter routes which means more packages and more money.
You may be asking, why not only make left turns instead of right to solve the loop issue? Left turns are both more dangerous and less efficient. In order to turn left, you need to sit and wait for gaps in oncoming traffic. Once you finally decide to move, any small miscalculation in how fast the approaching cars are coming could mean a crash. On top of this, it is significantly harder to see pedestrians during left turns. An estimated one quarter of pedestrian crashes in the U.S. take place due to simply turning left. All of these problems are magnified when dealing with trucks instead of cars. Right turns, on the other hand, are much more efficient and safer. Drivers can even turn right on certain stoplights decreasing the time they spend idling.
Overall, the system of avoiding left turns was extremely profitable for UPS. Routes became faster and idle time decreased, thus minimizing how much money was spent on fuel. UPS estimates that 10 million tons of fuel are saved per year as each route is decreased by an average of 6 – 8 miles. This is also beneficial for the environment as UPS trucks spend less time on the roads. It prevents an estimated 100,000 tons of CO2 being released per year. But most of all, Loop Dispatch (later updated with GPS to the ORION system which still prioritizes right turns) was good for the profit margins of UPS. One mile per day per driver over the course of a year can save up to $50 million. This means, over the course of a year, UPS saves between $300 – $400 million.
To you, the average reader, this may not seem particularly impactful. If you want the most efficient route between 2 points, avoiding left turns will not do that. However, if you have siblings who still trick-or-treat, you could win them some candy. Try telling them to only take right turns when going from house to house: it’s (in principle) the same as the travelling salesman problem.
As someone who admittedly drives like a grandma and generally does not enjoy any of the aspects of driving that aren’t simply going straight, I can 100% appreciate UPS’ preference for right turns. Left turns require so much more judgment and so many more variables that turning right is far less stressful. No lanes are crossed and, as you mentioned, not incoming traffic is dodged. Also, is it just me or do other people consistently forget that turning right on red is a thing?
This was interesting to learn and I didn’t know that left turns were this dangerous. I have also seen how easy it is to make right turns especially on a red light so I always thought turning right to be simpler. The Traveling Salesman not only saves time, money, and lives, it increases the money UPS earns and manages to be good for the environment. Whoever discovered this must have been payed a lot. The last point you made about trick or treating is something that a lot of kids would definitely try out and would most likely be successful, great suggestion.
This post is so applicable to the mailing issues that arose recently and also Halloween! I never knew that UPS trucks didn’t turn right to save time and be more efficient. I, myself, hate taking left turns too. I always either miss my chance or dangerously ZOOM in fear of getting hit. I wonder how UPS deals with the roundabouts in New Jersey… although they are easier than left turns, they are pretty dangerous and nerve-wracking too!
This is a very interesting topic, and I don’t even know where you could have found this, let alone write a whole post on it. I think that this is a great example of how things that we may think are simple are actually very complex behind the scenes. I wonder if other delivery drivers have picked up on this or if UPS has just been ahead of the game for the last 3 decades.
I never knew this but it makes so much sense!! It’s crazy to see the way a factorial can estimate the possible number of paths… I guess math really is everywhere. It’s also crazy how much money (and time) a small adjustment can make in the delivery pattern. While gas is expensive and UPS is saving a lot of money, they are also benefiting in the environment by using the Loop Dispatch. Great post!
Wow if it wasn’t for the math to support it I would have a hard time believing that simply turning right can reduce their route by 6-8 miles per day! It’s amazing to think that a company found a way to benefit themselves and the environment at the same time! However, I do think that the motivation behind this change was solely monetary with an added side benefit of a greener company, and that unfortunately many other companies will only support the environment if there is a clear benefit to doing so. I do like the thought of applying this problem to trick-or-treating and I am a bit disappointed that I personally will not be able to capitalize on this as I could’ve in years past. Great Post!