system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does UPS (maybe others as well) save money on fuel by limiting the number of turns (left or right)?

I recall that the Mybuster's did this myth and concluded that is was plausible. What I don't understand is how does making the routes so they only turn a certain direction save money on fuel? What are the mechanics behind this?
gpt
In most locations you can turn right on a red light. Because of this the truck can almost always be in constant motion. Waiting to turn left at a light can take a while sometimes. That idling wastes gas and therefore money.