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Unprotected left turns are one of the most dangerous situations in driving. I consider myself a competent driver, haven't been in an accident in over two decade

by js2 4y ago

Unprotected left turns are one of the most dangerous situations in driving. I consider myself a competent driver, haven't been in an accident in over two decades, and I barely trust myself to make an unprotected left. I've heard that UPS (used to?) ban their drivers from making unprotected lefts. Not in a million years would I ever trust this maneuver to software. Humans screw it up all the time: https://old.reddit.com/r/IdiotsInCars/comments/uks7c2/unprotected_left_turns_are_hard_for_some_people/ https://old.reddit.com/r/IdiotsInCars/comments/uks7c2/unprot... (No accident, the driver just gets stuck when the light changes.) Here's a recent video of a Tesla driver videoing his car making the same unprotected left multiple times: https://www.youtube.com/watch?v=j0Kvsq9xB8c https://www.youtube.com/watch?v=j0Kvsq9xB8c Given how much supervision it requires, I don't see the advantage of letting the car do the driving here.

aidenn0 4y ago
In theory, an unprotected left should be easier for software than a human. The issue with them for humans is that there are too many places traffic (and pedestrians) can come from. For computers, once you solve the problem of seeing traffic coming from one direction, Nx the computing power can see traffic coming from N directions. The problem Tesla has is that they still can't do basic things reliably enough
- js2 4y ago
  Human drivers are also impatient, distractible, poor at judging speed, and have visual blind spots. But a big problem with a lot of unprotected lefts is poor visibility of oncoming traffic. The car just isn't in a great position to see down the road. Tesla has to deal with that same limitation.
  - salawat 4y ago
    Turns out computers have the same problems without the right hardware and programming, much of which would be dependent on the public to implement. There's a reason these problems stick around.
lelag 4y ago
That's probably a US-specific challenge. Unprotected left turns are much rarer in Europe due to widespread use of roundabouts which are probably much easier to handle for both humans and software.
- js2 4y ago
  They are common in Massachusetts but very few other states, though they do seem to be showing up in more places the last few years. I grew up with one nearby in Miami so I've never struggled with them but a U.S. driver facing a roundabout for the first time can be a comical and sometimes dangerous situation. "There's Big Ben kids! Parliament!" https://youtu.be/iAgX6qlJEMc https://youtu.be/iAgX6qlJEMc
pxmpxm 4y ago
Motorcycle rider here, cars doing left turns across oncoming traffic account for the majority of car x bike collisions. If the drivers' eyes aren't on you, you're about to join that statistic.
- enragedcacti 4y ago
  Just to add to that, the driver could also have failed to accurately judge the motorcycle's speed. Motorcycle's being so skinny and relatively uncommon makes drivers perceive them as going slower than they are and being farther away than they are. It's one of the many reasons speeding is so dangerous on a motorcycle, the driver might see you but still think they have a gap because their perception of speed is all wrong. It's much safer to go the speed a car would be going so that you align with what the driver expects to see day to day.

by js2 4y ago

aidenn0 4y ago

In theory, an unprotected left should be easier for software than a human. The issue with them for humans is that there are too many places traffic (and pedestrians) can come from. For computers, once you solve the problem of seeing traffic coming from one direction, Nx the computing power can see traffic coming from N directions. The problem Tesla has is that they still can't do basic things reliably enough

js2 4y ago
Human drivers are also impatient, distractible, poor at judging speed, and have visual blind spots. But a big problem with a lot of unprotected lefts is poor visibility of oncoming traffic. The car just isn't in a great position to see down the road. Tesla has to deal with that same limitation.
- salawat 4y ago
  Turns out computers have the same problems without the right hardware and programming, much of which would be dependent on the public to implement. There's a reason these problems stick around.

lelag 4y ago

That's probably a US-specific challenge. Unprotected left turns are much rarer in Europe due to widespread use of roundabouts which are probably much easier to handle for both humans and software.

js2 4y ago
They are common in Massachusetts but very few other states, though they do seem to be showing up in more places the last few years. I grew up with one nearby in Miami so I've never struggled with them but a U.S. driver facing a roundabout for the first time can be a comical and sometimes dangerous situation. "There's Big Ben kids! Parliament!" https://youtu.be/iAgX6qlJEMc https://youtu.be/iAgX6qlJEMc

pxmpxm 4y ago

Motorcycle rider here, cars doing left turns across oncoming traffic account for the majority of car x bike collisions. If the drivers' eyes aren't on you, you're about to join that statistic.

enragedcacti 4y ago
Just to add to that, the driver could also have failed to accurately judge the motorcycle's speed. Motorcycle's being so skinny and relatively uncommon makes drivers perceive them as going slower than they are and being farther away than they are. It's one of the many reasons speeding is so dangerous on a motorcycle, the driver might see you but still think they have a gap because their perception of speed is all wrong. It's much safer to go the speed a car would be going so that you align with what the driver expects to see day to day.