5 ms·

This looks a bit over-engineered? Roundabouts work mostly fine, reduce emissions, and are safer for pedestrians.

Dlanv 3y ago
Seems easier to do this than to rebuild every intersection in the world. And many roundabouts still need lights because lights prevent gridlock which roundabouts do not do.
- manuelabeledo 3y ago
  > Seems easier to do this than to rebuild every intersection in the world. Just the ones that need fixing, I guess? Also, this solution introduces a lot of new moving parts, doesn't address pedestrian safety, and savings may not be significant enough in the long term, compared to a roundabout. > And many roundabouts still need lights because lights prevent gridlock which roundabouts do not do. Most roundabouts are small enough, so they don't really need traffic lights. Regardless, gridlock happens usually only during peak hours, which would account for, say, 3-4 hours a day. Intuitively, roundabouts would be more efficient than these smart traffic lights ~80% of the time, and outside that, regular traffic lights would do.
  - AnimalMuppet 3y ago
    > > Seems easier to do this than to rebuild every intersection in the world. > Just the ones that need fixing, I guess? Which is the vast majority, at least in my part of the world. So, yeah, seems easier to do this than to rebuild (almost) every intersection in (this part of) the world.
    - manuelabeledo 3y ago
      I don't think I understand your point. The solution proposed by Google doesn't seem to be too efficient, for several reasons: * Traffic-aware lights already exist. This could already reduces stops in the vast majority of the cases. * Google's system requires the deployment of an intricate, city wide network of smart traffic lights, driven by AI. I couldn't begin to imagine the kind of maintenance that would require. * Regarding that, this is a proprietary solution. Cities would likely have to pay Google to keep the network working. To me, this draws some parallels to how Europe and the US handle house heating. Traditionally, houses in the US have oversized heating solutions, whereas European house construction is focused on insulation. Yes, swapping all the windows for energy efficient ones is more expensive in the short term, but it is cheaper in the longer term.
      - AnimalMuppet 3y ago
        1. Everything you say could be true, and Google's solution could still be more efficient than tearing up 90% of the intersections in the US. 2. Retiming the traffic lights is an answer to a problem. Google's approach is only one possible way of getting to that answer. There may be more efficient ways.
      - jsnell 3y ago
        It feels like you're misunderstanding something. This is not a system controlling lights in real-time. It's probably just generating a schedule as a CSV file that a city employee uploads to their existing traffic light control system.
      - ahahahahah 3y ago
        > Google's system requires the deployment of an intricate, city wide network of smart traffic lights, driven by AI. Did you just make this up? From the article: "company says that rolling the changes out can be a five-minute job that uses the city's existing management systems". Google's system isn't about some smart AI driven lights. It's basically just AI developed light schedules for dumb lights. It doesn't require any deployment. > Cities would likely have to pay Google to keep the network working. Oh, you really did just completely imagine some system of your own.
        manuelabeledo 3y ago
        > Oh, you really did just completely imagine some system of your own. Turns out, data acquisition and processing does cost money.
dvngnt_ 3y ago
sounds easier to upgrade signals than redesign roads
monkaiju 3y ago
Couldnt agree more, theyre better for pedestrians than any intersection.
- _justinfunk 3y ago
  Honest question, how are roundabouts better for pedestrians than intersections? At a light-controlled intersection, the traffic is forced stop for a period of time, allowing for safe passage.
  - hgomersall 3y ago
    They're not. Roundabouts with any significant volume of traffic are, for the most part, terrible for pedestrians. Some rare but progressive roundabouts have zebra crossings on every arm which make them much better, but the continuous flow nature of roundabouts make them pretty hazardous.
    - manuelabeledo 3y ago
      > They're not. Roundabouts with any significant volume of traffic are, for the most part, terrible for pedestrians. I don't think that's true in general [0] [1] > Some rare but progressive roundabouts have zebra crossings on every arm which make them much better Those are just... regular roundabouts? What would be the point on having roundabouts with no way for pedestrians to safely cross the street? [0] https://www.fdot.gov/agencyresources/roundabouts/benefits.shtm https://www.fdot.gov/agencyresources/roundabouts/benefits.sh... [1] https://www.iihs.org/topics/roundabouts https://www.iihs.org/topics/roundabouts
  - manuelabeledo 3y ago
    Mostly because of speed. Roundabouts physically force drivers to decrease speed. One may run a red light, but cement is hard to ignore.
asdff 3y ago
Many cities already have such centralized traffic light control systems in place. This tool is just optimizing what already exists.
renewiltord 3y ago
Two choices: adjust traffic signal timings or rebuild intersections into roundabouts. Supposedly the former is an over-engineered solution and the latter is the elegant one. Beggars belief.
barrkel 3y ago
Besides roundabouts often being bigger and more unpleasant to cross for pedestrians than an equivalent traffic-light junction, roundabouts have a sweet spot - low to moderate traffic, and sometimes heavy traffic when there's a balance of exit usage. When not all exits are used frequently, heavy traffic can starve entrance from roads whose exits are not used. Exiting traffic frees up a gap for entering traffic to use. If there's nobody exiting before your entrance, you don't get to join. Traffic lights are sometimes added to roundabouts to patch this.

Seems easier to do this than to rebuild every intersection in the world. And many roundabouts still need lights because lights prevent gridlock which roundabouts do not do.

manuelabeledo 3y ago
> Seems easier to do this than to rebuild every intersection in the world. Just the ones that need fixing, I guess? Also, this solution introduces a lot of new moving parts, doesn't address pedestrian safety, and savings may not be significant enough in the long term, compared to a roundabout. > And many roundabouts still need lights because lights prevent gridlock which roundabouts do not do. Most roundabouts are small enough, so they don't really need traffic lights. Regardless, gridlock happens usually only during peak hours, which would account for, say, 3-4 hours a day. Intuitively, roundabouts would be more efficient than these smart traffic lights ~80% of the time, and outside that, regular traffic lights would do.
- AnimalMuppet 3y ago
  > > Seems easier to do this than to rebuild every intersection in the world. > Just the ones that need fixing, I guess? Which is the vast majority, at least in my part of the world. So, yeah, seems easier to do this than to rebuild (almost) every intersection in (this part of) the world.
  - manuelabeledo 3y ago
    I don't think I understand your point. The solution proposed by Google doesn't seem to be too efficient, for several reasons: * Traffic-aware lights already exist. This could already reduces stops in the vast majority of the cases. * Google's system requires the deployment of an intricate, city wide network of smart traffic lights, driven by AI. I couldn't begin to imagine the kind of maintenance that would require. * Regarding that, this is a proprietary solution. Cities would likely have to pay Google to keep the network working. To me, this draws some parallels to how Europe and the US handle house heating. Traditionally, houses in the US have oversized heating solutions, whereas European house construction is focused on insulation. Yes, swapping all the windows for energy efficient ones is more expensive in the short term, but it is cheaper in the longer term.
    - AnimalMuppet 3y ago
      1. Everything you say could be true, and Google's solution could still be more efficient than tearing up 90% of the intersections in the US. 2. Retiming the traffic lights is an answer to a problem. Google's approach is only one possible way of getting to that answer. There may be more efficient ways.
    - jsnell 3y ago
      It feels like you're misunderstanding something. This is not a system controlling lights in real-time. It's probably just generating a schedule as a CSV file that a city employee uploads to their existing traffic light control system.
    - ahahahahah 3y ago
      > Google's system requires the deployment of an intricate, city wide network of smart traffic lights, driven by AI. Did you just make this up? From the article: "company says that rolling the changes out can be a five-minute job that uses the city's existing management systems". Google's system isn't about some smart AI driven lights. It's basically just AI developed light schedules for dumb lights. It doesn't require any deployment. > Cities would likely have to pay Google to keep the network working. Oh, you really did just completely imagine some system of your own.
      - manuelabeledo 3y ago
        > Oh, you really did just completely imagine some system of your own. Turns out, data acquisition and processing does cost money.

dvngnt_ 3y ago

sounds easier to upgrade signals than redesign roads

monkaiju 3y ago

Couldnt agree more, theyre better for pedestrians than any intersection.

_justinfunk 3y ago
Honest question, how are roundabouts better for pedestrians than intersections? At a light-controlled intersection, the traffic is forced stop for a period of time, allowing for safe passage.
- hgomersall 3y ago
  They're not. Roundabouts with any significant volume of traffic are, for the most part, terrible for pedestrians. Some rare but progressive roundabouts have zebra crossings on every arm which make them much better, but the continuous flow nature of roundabouts make them pretty hazardous.
  - manuelabeledo 3y ago
    > They're not. Roundabouts with any significant volume of traffic are, for the most part, terrible for pedestrians. I don't think that's true in general [0] [1] > Some rare but progressive roundabouts have zebra crossings on every arm which make them much better Those are just... regular roundabouts? What would be the point on having roundabouts with no way for pedestrians to safely cross the street? [0] https://www.fdot.gov/agencyresources/roundabouts/benefits.shtm https://www.fdot.gov/agencyresources/roundabouts/benefits.sh... [1] https://www.iihs.org/topics/roundabouts https://www.iihs.org/topics/roundabouts
- manuelabeledo 3y ago
  Mostly because of speed. Roundabouts physically force drivers to decrease speed. One may run a red light, but cement is hard to ignore.

asdff 3y ago

Many cities already have such centralized traffic light control systems in place. This tool is just optimizing what already exists.

renewiltord 3y ago

Two choices: adjust traffic signal timings or rebuild intersections into roundabouts. Supposedly the former is an over-engineered solution and the latter is the elegant one. Beggars belief.

barrkel 3y ago

Besides roundabouts often being bigger and more unpleasant to cross for pedestrians than an equivalent traffic-light junction, roundabouts have a sweet spot - low to moderate traffic, and sometimes heavy traffic when there's a balance of exit usage. When not all exits are used frequently, heavy traffic can starve entrance from roads whose exits are not used. Exiting traffic frees up a gap for entering traffic to use. If there's nobody exiting before your entrance, you don't get to join. Traffic lights are sometimes added to roundabouts to patch this.