Why UPS drivers don't turn left and you probably shouldn't either
theconversation.com
theconversation.com
I'm solving for "How do I get to work" or "How to get to the grocery store". I'm taking the highway 80% of the distance, then my work is on the left... do I take 3 right turns to get there circling a potentially large city block? The UPS driver might well have stops on those side streets, I don't.
The idea behind this is sound, but it doesn't necessarily apply to the way individuals who aren't driving package routes should drive.
I'm kind of leaning toward the latter. Not so much that it never happened, but more that it was something that some data scientist said was a good idea, but never actually works I practice, and so UPS drivers don't actually follow this. Maybe it's a policy. I don't know. I don't have a list of UPS policies handy at the moment. But of the (admittedly small) sample size I've discussed it with, every single one says they do not follow that policy, or is it something they were instructed to do.
Which makes me kind of roll my eyes whenever I see these articles or podcasts or what-have-you. They pop up fairly frequently, but... it feels more like clever marketing by UPS than an actual policy.
(in the US) In very suburban streets in the middle of the day, nobody cares about turning left in an empty street. In more congested and wider streets it could get more delaying. But if the planning has been done by a software before the driver took the truck, the software might have avoided as many left turns as possible without telling the driver, and without having any need to ask the driver to micro-optimize themselves, they just follow the GPS (you probably can't do better), or the most sensical path ca't do better), or do a slight detour to get a snack (unforseeable).
Long story short it might be a software policy without being a driver policy, that would be enough to have a significant statistical result, I don't think drivers re-plan their shift.
The UPS route-planning system is called ORION.
>they just follow the GPS
I'd reckon that anyone on a bid route or other route that they are familiar with can do better than what ORION gives us. We aren't taking solely distance into account, that would be far too simple. We're considering other factors too, including hard time constraints like next day air commit times, regularly scheduled pickups, irregular pickups, business hours, and whether we can even physically access the packages [0, 1] that the system wants us to deliver.
>I don't think drivers re-plan their shift.
We most certainly do, we wouldn't finish the day if we blindly followed trace.
This article is more about the way routes are planned than the individual choices drivers make along those routes. There isn't a lot of room for agency in route choosing, drivers are given a stack of packages and deliver them in the way the route is built.
https://www.ups.com/us/en/services/knowledge-center/article....
(This link claims they had 55,000 drivers using the system in 2016.)
In any case, a left turn in this situation is preferable in suburban and semi rural areas.
Umm, I’ll do a u turn.
Used to happen all the time.
This leads to it picking absurd routes.
So it’s a tangent on the topic of routing and left turns.
If this works in general for typical routes driven by individuals (rather than only for delivery routes like a UPS driver is making with multiple stops that don't have to happen in any particular order) then it would make sense for individuals to do it and they could benefit by doing it without needing anyone else to do it as well. There is no prisoner's dilemma here.
In theory, this would be useful for truck drivers or prioritizing passenger pickup locations.
But now, I use it as an example of overengineering and overoptimization.
In practice, the main concern should be reducing cognitive load on the driver. Additional instructions, rules that can be potentially broken, inconsistencies in logic, all of it poses a substantial risk.