5 ms·

Not unique to Pittsburgh (also prevalent in Rhode Island, among other places), but more importantly, letting the first car turn left first is useful to keeping

Not unique to Pittsburgh (also prevalent in Rhode Island, among other places), but more importantly, letting the first car turn left first is useful to keeping traffic flowing on narrow roads—which, in the areas that use this tactic, rely on it. So, not following local customs is a good way to snarl traffic (since the oncoming traffic will be waiting for the car to take its turn).

fjsolwmv 8y ago
Obviously if the law is wrong it should be changed. Then the question becomes, can a car be programmed to follow the more complex law.
- sharonzhou 8y ago
  I think it's less about complexity and more about precision. A simple law can be extremely difficult to encode if it lacks specification.
systoll 8y ago
Not that I'd recommend doing it in an area not used to it... but that sounds like a riskier alternative to a hook turn. With hook turns, If you want to turn right, you start in the leftmost lane. When your light goes green, you 'hook' around to put yourself in front of the cars to your [initial] left. From there, the road you want to enter is straight ahead. This way, no-one cuts across lanes where traffic has a green light.
- Noumenon72 8y ago
  This makes no sense to me even after assuming you are from a country that drives on the left and reading the Wikipedia page.
  - melkiaur 8y ago
    Ok, let's use normal right-sided driving method. Imagine you're vulnerable (on a bike, or worse: on an electric scooter), and you want to turn left. You were going northbound and want to go westbound. In "normal" fashion, you'd have to stay on the left of your lane, and wait for the traffic coming in front of you to die down before you can cross. That puts you straight in the middle of the intersection for some time, which is dangerous. With a hook turn, you go and wait along with the traffic coming from the east to the west. They are stopped, so they are not a danger to you. When the east-west traffic light finally turns green, you won't be crossing anyone's traffic, and you'll be already standing on the rightmost part of your new road.
    - zaphirplane 8y ago
      Fairly sure the hook turn isn’t about safety, it’s about traffic flow. If it’s about safety it would be see more usage across the world
      - resonantjacket5 8y ago
        Its used in denmark Australia etc anywhere with sufficient bike lanes or of the intersection is reallt large
        zaphirplane 8y ago
        No In Australia it’s for the benefit of the tram https://en.m.wikipedia.org/wiki/Hook_turn https://en.m.wikipedia.org/wiki/Hook_turn the article seems to imply it’s otherwise for traffic flow and 1 country for the benefit of cyclists
      - lemoncucumber 8y ago
        It's definitely safer, and it does see quite a bit of usage in areas of the world with high quality cycling infrastructure. The fact that it doesn't see more usage is just a testament to the fact that most urban planners around the world don't care much about keeping cyclists safe.
  - lemoncucumber 8y ago
    First off, note that hook turns are a bike thing, not a car thing — trying to imagine it with cars isn’t going to make any sense. They rely on the fact that bikes are small enough that they can fit in the space in front of the stopped opposite-direction cars (which might be a crosswalk, bike box, etc). You just go stop there, turn your bike so it’s pointing the right direction, and wait for the green. They work even better with dedicated bike infrastructure as depicted in the diagram about half way through this article: https://www.vox.com/2015/8/12/9139771/protected-intersection-bike-davis https://www.vox.com/2015/8/12/9139771/protected-intersection...
    - jpatokal 8y ago
      Not a car thing? Welcome to Melbourne, Australia! https://www.youtube.com/watch?v=Yh92LirlCf8 https://www.youtube.com/watch?v=Yh92LirlCf8 My wife used to drive in the Melbourne CBD daily for work, but would always go around the block instead of attempting one.
- bryanlarsen 8y ago
  You're confusing people because you're talking from a left-hand drive perspective. This is known in the right-hand drive cycling world as a Copenhagen left, and many consider it to be bad infrastructure design. http://www.aviewfromthecyclepath.com/2010/07/not-really-so-great-cycle-path-design.html http://www.aviewfromthecyclepath.com/2010/07/not-really-so-g...

fjsolwmv 8y ago

Obviously if the law is wrong it should be changed. Then the question becomes, can a car be programmed to follow the more complex law.

sharonzhou 8y ago
I think it's less about complexity and more about precision. A simple law can be extremely difficult to encode if it lacks specification.

systoll 8y ago

Not that I'd recommend doing it in an area not used to it... but that sounds like a riskier alternative to a hook turn. With hook turns, If you want to turn right, you start in the leftmost lane. When your light goes green, you 'hook' around to put yourself in front of the cars to your [initial] left. From there, the road you want to enter is straight ahead. This way, no-one cuts across lanes where traffic has a green light.

Noumenon72 8y ago
This makes no sense to me even after assuming you are from a country that drives on the left and reading the Wikipedia page.
- melkiaur 8y ago
  Ok, let's use normal right-sided driving method. Imagine you're vulnerable (on a bike, or worse: on an electric scooter), and you want to turn left. You were going northbound and want to go westbound. In "normal" fashion, you'd have to stay on the left of your lane, and wait for the traffic coming in front of you to die down before you can cross. That puts you straight in the middle of the intersection for some time, which is dangerous. With a hook turn, you go and wait along with the traffic coming from the east to the west. They are stopped, so they are not a danger to you. When the east-west traffic light finally turns green, you won't be crossing anyone's traffic, and you'll be already standing on the rightmost part of your new road.
  - zaphirplane 8y ago
    Fairly sure the hook turn isn’t about safety, it’s about traffic flow. If it’s about safety it would be see more usage across the world
    - resonantjacket5 8y ago
      Its used in denmark Australia etc anywhere with sufficient bike lanes or of the intersection is reallt large
      - zaphirplane 8y ago
        No In Australia it’s for the benefit of the tram https://en.m.wikipedia.org/wiki/Hook_turn https://en.m.wikipedia.org/wiki/Hook_turn the article seems to imply it’s otherwise for traffic flow and 1 country for the benefit of cyclists
    - lemoncucumber 8y ago
      It's definitely safer, and it does see quite a bit of usage in areas of the world with high quality cycling infrastructure. The fact that it doesn't see more usage is just a testament to the fact that most urban planners around the world don't care much about keeping cyclists safe.
- lemoncucumber 8y ago
  First off, note that hook turns are a bike thing, not a car thing — trying to imagine it with cars isn’t going to make any sense. They rely on the fact that bikes are small enough that they can fit in the space in front of the stopped opposite-direction cars (which might be a crosswalk, bike box, etc). You just go stop there, turn your bike so it’s pointing the right direction, and wait for the green. They work even better with dedicated bike infrastructure as depicted in the diagram about half way through this article: https://www.vox.com/2015/8/12/9139771/protected-intersection-bike-davis https://www.vox.com/2015/8/12/9139771/protected-intersection...
  - jpatokal 8y ago
    Not a car thing? Welcome to Melbourne, Australia! https://www.youtube.com/watch?v=Yh92LirlCf8 https://www.youtube.com/watch?v=Yh92LirlCf8 My wife used to drive in the Melbourne CBD daily for work, but would always go around the block instead of attempting one.
bryanlarsen 8y ago
You're confusing people because you're talking from a left-hand drive perspective. This is known in the right-hand drive cycling world as a Copenhagen left, and many consider it to be bad infrastructure design. http://www.aviewfromthecyclepath.com/2010/07/not-really-so-great-cycle-path-design.html http://www.aviewfromthecyclepath.com/2010/07/not-really-so-g...