5 ms·
you mean it's already invented? than it should. (i just never met this function in programs i used)
by fedd 15y ago
you mean it's already invented? than it should. (i just never met this function in programs i used)
- munin 15y agoUPS uses this in the direction software their delivery vans use. minimization of left turns means the vans get everywhere faster and more packages are delivered in a given day.
- moheeb 15y agoI wish the US/state governments would do the same thing. I hate how the green left-turn arrow is the first thing to light at a stoplight. This penalizes efficiency and rewards a behavior that costs us all time and energy. Why is it like this? The only valid reason I can think of is that turn lanes would tend to back up at most lights in busy cities. I would think correcting this behavior would help reduce the number of vehicles turning, to offset the backup.
- epikur 15y agoYou should check out the "Michigan left" which is being increasingly implemented around the country. A Michigan left prevents backup by having people turn right and then do a U-turn further down the road at a designated area.
- deleted 15y ago[deleted]
- moheeb 15y agoThanks for the concept epikur! This is better, but it seems this design would not work on very busy roads. You would never get a chance to cross oncoming traffic due to the volume. This does seem perfect for most Midwestern highways where space is not really a concern and traffic is relatively light.
- kd5bjo 15y agoThey installed one of these a few years ago where I live. Each U-turn area gets its own traffic light in addition to the light at the grade crossing; I don't drive through there often enough to know how the patterns are synchronized for the different lights.
- jaylevitt 15y agoFor one highway and one non-highway, check out SPUIs: http://www.youtube.com/watch?v=mwpoPQ1SPJU http://www.youtube.com/watch?v=mwpoPQ1SPJU
- mbreese 15y agoUPS considers it highly proprietary, so I'm not surprised that you haven't come across their implementation.
- larrik 15y agoI had some customers who used it (Anheuser-Busch has some weird licensing partnership that their distributors get it for free-ish). So you CAN get it, if you have the money.
- Figs 15y agoJust take Dijkstra's Algorithm (or possibly A* if you want to try to optimize the runtime performance) and give a higher cost to edges in your map that correspond to left turns. Now it's just a matter of tuning the additional weight added to suit your preference. You won't get the shortest distance any more, just the "cheapest" path in terms of the distance/left-turn weight; if you find you have to go too far out of your way to avoid left turns, you may want to reduce the added weight so you can make a few more left turns without going so far away. For example, you probably don't want to go 10 miles down the freeway and another 10 back to avoid a single left turn on what would otherwise be a 5 minute drive, but maybe you'd instead be willing to drive a 1/2 mile to avoid a left turn that you'd otherwise have had routed -- so route the left turn as whatever distance it would be plus 1/2 mile additional cost.