3 ms·

Sad thing is this probably won’t work in the real world due to nimby types.

bobthepanda 6y ago
I mean this wouldn't really work because it really optimizes one mode of travel (the car) at the expense of nearly everyone else. People still need time to cross the street on foot or on a bicycle.
- toast0 6y ago
  It's hard to tell exactly what the article is arguing for. I don't know what the status quo on traffic control is for Mexico City. I know some big cities have all their lights on a set schedule. Some big cities have a fully integrated system where intersections communicate and predict arrivals to one intersection based on exits from another. I think the researcher is suggesting that prediction is too difficult to make good results from fixed scheduling or communicating intersections, and that instead, each intersection should adapt to its local sensors. That can include bike detectors and pedestrian buttons. I think this idea generally works. I've seen lots of traffic signals that respond to cars, bikes, and pedestrians (via button, sadly, I've never seen an inductive loop detector in a sidewalk, would have to be sensitive to count a person). You get better results if you can put sensors a bit back from the intersection to determine queue length, although that adds some expense. It's also nice if traffic controls can be placed into an event mode to help traffic disperse from things like sporting events, commuter trains, and ferries; at least for a few intersections around the site, adaptation may not be enough if there's steady cross traffic, during the event, it may be more efficient to make cross traffic wait longer than normal reasonable limits, or add a cycle for all direction walking, so pedestrians can make diagnol crossings more easily, etc. Cars idling at a stop light when there's no conflicting traffic (including bikes and peds) is bad for everyone, not just cars. Reducing that is good for everyone, at least in the small --- as the article mentions, improved traffic conditions may encourage more driving, which may not be beneficial for bikes and peds.
  - bryanrasmussen 6y ago
    you sound like you have some expertise on this, so I would like your opinion on the following: on my street they have put up signs that display how many seconds it is to the light shift at the cross walk, ostensibly for bikes, but totally readable by cars - it's about 4 houses to the light. It struck me as being idiotic and wasteful for the environment to have made this sign and to use the electricity to power it, but also I would think there would be side effects to the traffic flow that would actually make the sign counterproductive - do you know what the usefulness of these signs is?
    - tsjq 6y ago
      The timer display is to keep people relaxed and to reduce unnecessary revving the throttle due to impatience while waiting for the red to turn green.
      - bryanrasmussen 6y ago
        Ok, but it really looks like it is placed for the benefit of cyclists coming down the hill of the street. Also it is far enough back that when you are waiting for it to turn green you can't see it.
    - cseleborg 6y ago
      Doesn't answer your questions, but this reminds me of the traffic lights in india that reset the counter when car drivers honk too much :-) https://edition.cnn.com/2020/02/05/india/mumbai-traffic-lights-tests-scli-intl/index.htm https://edition.cnn.com/2020/02/05/india/mumbai-traffic-ligh...
      - bryanrasmussen 6y ago
        damn, I would like to put one of those in Naples, but I guess Neapolitan drivers aren't much for stopping at lights anyway.
      - frosted-flakes 6y ago

I mean this wouldn't really work because it really optimizes one mode of travel (the car) at the expense of nearly everyone else. People still need time to cross the street on foot or on a bicycle.

toast0 6y ago
It's hard to tell exactly what the article is arguing for. I don't know what the status quo on traffic control is for Mexico City. I know some big cities have all their lights on a set schedule. Some big cities have a fully integrated system where intersections communicate and predict arrivals to one intersection based on exits from another. I think the researcher is suggesting that prediction is too difficult to make good results from fixed scheduling or communicating intersections, and that instead, each intersection should adapt to its local sensors. That can include bike detectors and pedestrian buttons. I think this idea generally works. I've seen lots of traffic signals that respond to cars, bikes, and pedestrians (via button, sadly, I've never seen an inductive loop detector in a sidewalk, would have to be sensitive to count a person). You get better results if you can put sensors a bit back from the intersection to determine queue length, although that adds some expense. It's also nice if traffic controls can be placed into an event mode to help traffic disperse from things like sporting events, commuter trains, and ferries; at least for a few intersections around the site, adaptation may not be enough if there's steady cross traffic, during the event, it may be more efficient to make cross traffic wait longer than normal reasonable limits, or add a cycle for all direction walking, so pedestrians can make diagnol crossings more easily, etc. Cars idling at a stop light when there's no conflicting traffic (including bikes and peds) is bad for everyone, not just cars. Reducing that is good for everyone, at least in the small --- as the article mentions, improved traffic conditions may encourage more driving, which may not be beneficial for bikes and peds.
- bryanrasmussen 6y ago
  you sound like you have some expertise on this, so I would like your opinion on the following: on my street they have put up signs that display how many seconds it is to the light shift at the cross walk, ostensibly for bikes, but totally readable by cars - it's about 4 houses to the light. It struck me as being idiotic and wasteful for the environment to have made this sign and to use the electricity to power it, but also I would think there would be side effects to the traffic flow that would actually make the sign counterproductive - do you know what the usefulness of these signs is?
  - tsjq 6y ago
    The timer display is to keep people relaxed and to reduce unnecessary revving the throttle due to impatience while waiting for the red to turn green.
    - bryanrasmussen 6y ago
      Ok, but it really looks like it is placed for the benefit of cyclists coming down the hill of the street. Also it is far enough back that when you are waiting for it to turn green you can't see it.
  - cseleborg 6y ago
    Doesn't answer your questions, but this reminds me of the traffic lights in india that reset the counter when car drivers honk too much :-) https://edition.cnn.com/2020/02/05/india/mumbai-traffic-lights-tests-scli-intl/index.htm https://edition.cnn.com/2020/02/05/india/mumbai-traffic-ligh...
    - bryanrasmussen 6y ago
      damn, I would like to put one of those in Naples, but I guess Neapolitan drivers aren't much for stopping at lights anyway.
    - frosted-flakes 6y ago