Comment by BugsJustFindMe

Comment by BugsJustFindMe 5 days ago

Both may be legal, but the first one is unclear and is definitely unsafe. Safety requirements dictate a slightly different understanding of yellow light than is commonly used by drivers. For safety, yellow must mean "begin controlled deceleration immediately". The first driver had plenty of time on yellow to not be just barely entering the intersection on red. They clearly were not decelerating and had very likely sped up to beat the light. This unquestionably is a thing that drivers do all the time, and it's dangerous.

Ajedi32 5 days ago

Why is it dangerous? (Unless they're breaking the speed limit to make the light, obviously.) Just the risk that they might misjudge the timing and enter the intersection after the light turns red? But lights have a built in delay before turning green to account for that.

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cptskippy 5 days ago

Because vehicles are often already traveling at or above the speed limit.
Just as the yellow light is intended as a "start slowing down" but is interpreted as "speed up to beat the light", the speed limit sign is intended as a "do not exceed this speed" but is interpreted as "you must be traveling this speed".
If we assumed that most vehicles are traveling the speed limit or faster, which is the case in my experience, then accelerating further is like pouring gasoline on a fire.

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- ImPostingOnHN 5 days ago
  
  I think they question they were asking was: What is the fire upon which gasoline is being poured?
  Given that, even if someone entered the intersection on yellow, they would be out of the intersection before perpendicular cars/bicycles/pedestrian signals turn green, how is it dangerous?
  It seems the risk of collision is 0 as long as neither the driver nor the perpendicular cars/bicycles/pedestrians are illegally running red signals.
  
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simiones 5 days ago

This is very much wrong.

When a driver sees a yellow light, they must make a call: do I have time to safely slow down and stop before reaching the stop location, or not? If I do, then I must start slowing down right away - that much we agree o. But if I don't, then I mustn't slow down, as that is more likely to leave me in the middle of the intersection while the lights turn green for through-traffic.

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the__alchemist 5 days ago

> yellow must mean "begin controlled deceleration immediately"

This is not true in the strong form you used. There is a regime where there is no possibility you will be able to stop the vehicle in time using reasonable deceleration. Slowing does no good. There is also a regime where slowing will cause you to enter the intersection during the red light, and not decelerating will not.

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BugsJustFindMe 5 days ago

That's ok. We can hammer out the details together, but the principle is true if the light turns yellow before you reach the intersection. Note that I didn't say how rapidly you need to be decelerating, and if the light has turned red before the car even clears the crosswalk, as is the case for the first car, then the driver sped up instead of slowing down.

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munchler 5 days ago

Again, please be aware that the video does not show the entire intersection.

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BugsJustFindMe 5 days ago

It seems like you're stuck on whether someone broke a red light law, but this isn't an article about the legality of dangerous behaviors. It's an article about making intersections more dangerous.
The first car isn't even through the crosswalk when the light turns red. Racing through a crosswalk to beat a light is the definition of dangerous driving.

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