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Comment by cortesoft | Hacker News Reader

The video and article specifically said these cars “ran the red light”, which they absolutely did not do.

you're supposed to slow down at a yellow to prepare to stop, not speed up to get through it, increasing speed through an intersection is inherently dangerous

the author's point is valid and we're falling into pedantry

It depends on how far from the intersection you are. If you can’t stop before the intersection, you shouldn’t slow down because you need to get through the intersection in time.

Those cars didn’t have time to stop safely. They would have had to slam on the breaks, which is very dangerous because the car behind you might not stop in time. Speeding up to get through in time is the right decision if you are very close to the intersection when the light turns yellow.

Speeding up is only the right decision because it's a poorly designed intersection.

There is no intersection design that could avoid this. Some people are going to be too close to the intersection to stop in time when they see yellow no matter what you do.

That doesn't excuse speeding up, though – if the yellow light is long enough, you will always be able to either a) safely stop with a certain given maximum deceleration, or else b) continue at your current speed and enter the intersection before the light turns red.

That's rubbish, it's provable mathematically that given any speed limit it's possible to avoid an overlapping "dilemma zone" that requires speeding up

(v²) / (2a) ≤ (v × t_y) + L

v = vehicle speed (meters per second)

a = comfortable deceleration rate (meters per second squared)

t_y = yellow light duration (seconds)

L = length of the intersection (meters)

You can calculate the minimum yellow time for this using t_y ≥ (v / 2a) - (L / v)

This is rudimentary and doesn't account for reaction time, but a simple buffer would suffice.

The failure is largely in poor planning and poor human behavior.

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