It's a neat thought, and everyone who's watched a light turn red ahead of them just as they cleared a green has thought it before, but there is a serious downside. Urban stoplights should be optimized for the safety of non-motorists (pedestrians and cyclists) above all else. Giving cars more uninterrupted travel leads to higher speeds and more collisions. I'm happy that where I live there's more attention paid to traffic calming and bicycle infrastructure than motorist travel-time optimization.
Smarter programming of stoplights could improve efficiency of urban traffic
21–30 of 46 posts
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#22Startup opportunity: micro payments to change the light green in your direction ASAP. Voice-activated bidding with a floating fee that everyone sitting at the light can contribute towards.
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#23With all the image processing cameras out there, and the cameras already mounted on the traffic lights, it boggles the mind that nobody is making traffic light controllers that optimize traffic based on current conditions and a cost function. For example, if 5 cars are coming from one direction, turn the light red for the 1 car on the cross street. I'm pretty fed up with the light perversely stopping the 5 cars at th…
I would like to see this as a temporary fix for when a signal goes down... toss a bolas with a camera + light that wraps around the cross-bar and can temporarily handle things. (Good luck getting it down!)
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#24Earlier quoted context omitted.
While traffic lights are mission critical, we can absolutely make it fool proof, the first time. It's actually not very difficult. Don't forget, many lights right now are using weight sensors in the ground (SEE EDIT-2), A. that is very costly, B. They are prone to damage...a lot of the time, and C. with current technology in cameras, I'd say they will be more reliable and give better information about on-coming cars…
I'm pretty certain there no lights that have "weight" sensors. The sensors for triggering signal changes use large induction loops to detect when ferrous metal (a car frame) is near by.
Yep as I found out with my Carbon road bike, they don't see me (or a bunch of us) which can be fun.
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#25Virginia currently uses smart traffic signals: > Traffic-responsive signals vary the timing of the lights according to the amount of traffic. They use sensors to detect the number of vehicles on an approach. The time the light stays green adjusts to let as many drivers as possible through before the signal changes to respond to traffic coming from another direction. Back when I lived in NoVa, the lights near me had t…
Lots of lights have inductive loops to detect cars, but they are too close to the lights. The cars have already stopped by the time the loop detects them.
How does the Virginia system detect the cars?
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#26There is an interesting side effect here. Autonomous learning.
Basically when the stoplights in my city switched to a 'three program' light (they have 'normal workday', 'normal non-work day' and 'commute' patterns available it means that people who drive "on autopilot" start having the wrong thing anticipated when they are sitting at the light, (for example expecting a left turn signal to go green before oncoming traffic gets the green, or expecting turn signals to activate before through traffic) and that leads to some interest effects. Most notably people "jumping" into traffic when their anticipation is incorrect.
The other thing that this does with non-native/less well trained drivers, is put them in lose-lose situations. I got out and talked to a guy who was sitting in a non-left lane (it was one lane over), waiting for the left turn light to activate. I explained to him (he barely spoke english) that from the lane he was sitting, the left turn light would NEVER activate and by sitting there while the light in front of him was green he was at risk of being hit by a car. He had no clue. It was very sad.
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#27With all the image processing cameras out there, and the cameras already mounted on the traffic lights, it boggles the mind that nobody is making traffic light controllers that optimize traffic based on current conditions and a cost function. For example, if 5 cars are coming from one direction, turn the light red for the 1 car on the cross street. I'm pretty fed up with the light perversely stopping the 5 cars at th…
While this sounds great on paper you have to remember that traffic signals are absolutely mission critical components to the traffic system and what you are describing pushes them to the cutting edge of what many might consider "experimental" technology. There can be no trial and error. Also remember that traffic systems are not developed by start ups that can iterate quickly with seemingly endless funding and/or no…
Think I remember reading that the failsafes in traffic signals are hard-wired. e.g. the green light in one direction is grounded through the green light in the crossing direction, so they can't both be illuminated at the same time. The idea is that no matter what goes wrong with the control software or sensors, you can't get conflicting green lights.
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#28Earlier quoted context omitted.
Sounds like a startup needs to start start developing and licensing traffic light software to municipalities. Seems reasonable enough to me.
That's not a terrible idea but once again you run into the issues of reliability and budget. At the end of the day you need to convince city officials to spend what little money they have remaining in their budget on your new system because it offers a greater value than all of their other proposed upgrades to the city AND that what you have is as reliable or better than the current system they have in place. This me…
The city already has no problem funding cameras mounted on every traffic light, and all kinds of other surveillance equipment. A generic, self-adapting light controller would work for probably 90% of intersections. I'm hard pressed to see how it would be that expensive.
It would not be hard to put in a physical interlock so both lights could not be simultaneously green, regardless of what the software commands. I don't believe this is a significant fatality risk.
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#29Or, we could use roundabouts[0] [0]: http://www.wsdot.wa.gov/Safety/roundabouts/benefits.htm
Roundabouts are OK but they don't work so well on multi-lane roads. The multi-lane roundabouts I've seen are confusing to most motorists and tend to slow to a crawl. The problem is there is limited space to change lanes once you are on the roundabout, so you have to enter in the proper lane based on where you want to exit. Inevitably there's someone who didn't use the proper lane and everything clogs up while they stop and wait for a gap in the next lane (which happens rarely because roundabouts promote continuous traffic flow).
Re: Smarter programming of stoplights could improve efficiency of urban traffic
#30I sometimes get the feeling that traffic signals in my home town (Chicago) are designed to maximize ticket and speed camera revenue, rather than improve the flow.
> I sometimes get the feeling that traffic signals in my home town (Chicago) are designed to maximize ticket and speed camera revenue, rather than improve the flow. You get that feeling because it's true: http://www.chicagotribune.com/news/watchdog/redlight/ct-yell...
The hidden cost of living in a bankrupt city (and state).