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How UPS trucks saved millions of dollars by eliminating left turns

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Re: How UPS trucks saved millions of dollars by eliminating left turns

#11

Post by Naga »

mstade wrote: post #8

> In the US, and other countries where you drive on the right side of the road, right turns are free, but for a left turn you need to wait for a green light. I don't know of any other country than the US where turning right on red is allowed, unless there's specific signage or additional traffic lights to allow it. Indeed, the turn-on-red rule in the US seems to work inverse to how I've seen it elsewhere – i.e. it's…

It is legal to turn right on a red light in Canada, except the Isle of Montreal. It actually used to be illegal in all of Quebec until 2003.

Re: How UPS trucks saved millions of dollars by eliminating left turns

#12

Post by pc86 »

snrplfth wrote: post #10
amelius wrote: post #4

Does typical navigation software assign the same cost to a left turn as a right turn?

If your navigation software doesn't permit weighting different turns, it's not really worth using for a business/organization of any substantial size. Usually there's also cost assignment/weighting for things like traffic time, stoplights-vs-all-way-stops, effective speed limits, time-vs-distance balancing, and all the zonal assignments that come up when breaking up a bunch of stops into different vehicles' routes fo…

They're asking about typical nav software, not large business logistics software.

Re: How UPS trucks saved millions of dollars by eliminating left turns

#13

Post by pc86 »

leereeves wrote: post #6

> eliminating left turns wherever possible after it found that drivers have to sit idly in the trucks while waiting to take the left turn to pass through traffic. So, it created an algorithm that eliminated left turns from drivers’ routes even if meant a longer journey. Sounds reasonable. > In 2005 ... the total distance covered by its 96,000 trucks was reduced by 747,000km. In 2011, ... the company had reduced dista…

It won't always be longer, it just wasn't a deal breaker if it was.

Re: How UPS trucks saved millions of dollars by eliminating left turns

#14

Post by snrplfth »

Naga wrote: post #11
mstade wrote: post #8

> In the US, and other countries where you drive on the right side of the road, right turns are free, but for a left turn you need to wait for a green light. I don't know of any other country than the US where turning right on red is allowed, unless there's specific signage or additional traffic lights to allow it. Indeed, the turn-on-red rule in the US seems to work inverse to how I've seen it elsewhere – i.e. it's…

It is legal to turn right on a red light in Canada, except the Isle of Montreal. It actually used to be illegal in all of Quebec until 2003.

And in Quebec, you still see people turning right on red lights while looking solely to the right, instead of looking for oncoming traffic from the left.

Re: How UPS trucks saved millions of dollars by eliminating left turns

#16

Post by snrplfth »

pc86 wrote: post #12
snrplfth wrote: post #10

Earlier quoted context omitted.

If your navigation software doesn't permit weighting different turns, it's not really worth using for a business/organization of any substantial size. Usually there's also cost assignment/weighting for things like traffic time, stoplights-vs-all-way-stops, effective speed limits, time-vs-distance balancing, and all the zonal assignments that come up when breaking up a bunch of stops into different vehicles' routes fo…

They're asking about typical nav software, not large business logistics software.

Okay, I assumed the implication was software "typical" for commercial/delivery/collection vehicle routing. Even a business with a dozen vehicles would generally have this sort of software.

Google Maps does not, the last time I checked, preferentially weight left turns beyond expected stoplight delay time. However, Waze does, apparently. (But this is just a comparative observation, the algorithms are not public.)

Re: How UPS trucks saved millions of dollars by eliminating left turns

#17

Post by gjem97 »

leereeves wrote: post #6

> eliminating left turns wherever possible after it found that drivers have to sit idly in the trucks while waiting to take the left turn to pass through traffic. So, it created an algorithm that eliminated left turns from drivers’ routes even if meant a longer journey. Sounds reasonable. > In 2005 ... the total distance covered by its 96,000 trucks was reduced by 747,000km. In 2011, ... the company had reduced dista…

I think "created an algorithm" is probably overselling it a bit. Clearly they already had a route planner, didn't they just modify it to add extra cost to a left turn?

Re: How UPS trucks saved millions of dollars by eliminating left turns

#18

Post by [deleted] »

gjem97 wrote: post #17
leereeves wrote: post #6

> eliminating left turns wherever possible after it found that drivers have to sit idly in the trucks while waiting to take the left turn to pass through traffic. So, it created an algorithm that eliminated left turns from drivers’ routes even if meant a longer journey. Sounds reasonable. > In 2005 ... the total distance covered by its 96,000 trucks was reduced by 747,000km. In 2011, ... the company had reduced dista…

I think "created an algorithm" is probably overselling it a bit. Clearly they already had a route planner, didn't they just modify it to add extra cost to a left turn?

[deleted]

Re: How UPS trucks saved millions of dollars by eliminating left turns

#19

Post by helipad »

mstade wrote: post #8

> In the US, and other countries where you drive on the right side of the road, right turns are free, but for a left turn you need to wait for a green light. I don't know of any other country than the US where turning right on red is allowed, unless there's specific signage or additional traffic lights to allow it. Indeed, the turn-on-red rule in the US seems to work inverse to how I've seen it elsewhere – i.e. it's…

My brother came to Michigan to visit from the UK. After a few days he said:

"So, I can go on a red light for a right turn, but sometimes I have to wait at a green light for a left turn?"

It was then I realised how peculiar the signals in the US can be.

Re: How UPS trucks saved millions of dollars by eliminating left turns

#20

Post by snrplfth »

leereeves wrote: post #6

> eliminating left turns wherever possible after it found that drivers have to sit idly in the trucks while waiting to take the left turn to pass through traffic. So, it created an algorithm that eliminated left turns from drivers’ routes even if meant a longer journey. Sounds reasonable. > In 2005 ... the total distance covered by its 96,000 trucks was reduced by 747,000km. In 2011, ... the company had reduced dista…

It also tends to reduce distance travelled because left turns are often done to get onto faster roads - if you right-turn it all the way, you're often on slower roads, so you're not going as fast, but you're saving actual travel distance.
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