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It takes FAR more than 50ft to stop from 40mph. I doubt you can even react in 50ft.

40mph is 58 feet per second, so that’s less than a second to

Your “rule of thumb” is AT BEST highly misleading.

Typical humans take about 250ms to react, and that’s before you actually do anything. There’s 15ft (at least) gone before you even touch the pedal.

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Only a fool breaks the two-second rule: https://en.m.wikipedia.org/wiki/Two-second_rule

That rule explicitly states that it's not for being able to stop, though, it's just to have time to react to the driver ahead stopping. Two seconds isn't nearly enough to stop in front of a stationary object. At highway speeds it's even barely enough to not rear-end the vehicle ahead if it has to panic stop.

Yep, that’s right. Its a great rule though, and as explained in the article it works at any speed, highway or not. Personally I keep 4 seconds.

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