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A comment on Passenger with “no idea how to fly” lands plane after pilot incapacitated. Parent comment

Re:Passenger with “no idea how to fly” lands plane after pil... by nonameiguess on Wednesday May 11, 2022 @01:37PM (#31343256)
Just to quantify this, the shortest 60-0 stopping distance for a "consumer-grade" car (meaning not a formula one vehicle) is the Porsche 911, which can do it in 27m. This is nearly 6 vehicle lengths. Usual safety guidelines are to stay about 3 car lengths behind whoever you're following, so even world's greatest brakes are not gonna save you if the vehicle in front stops in 0m because it hits an immovable pile of already stopped objects itself.
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Re:Passenger with “no idea how to fly” lands plane after pil... by frob on Wednesday May 11, 2022 @01:48PM (#31343397)
3 car lengths seems way too close to be following at highways speeds. Assuming a car is about 16 ft long, that gives you less than half a second of reaction time at 70 mph. Even at 25 mph, it's still less than 1.5 seconds.

I very much prefer to be 3 SECONDS behind the person in front of me. It's a nice metric that works at basically all speeds above 30.

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Re:Passenger with “no idea how to fly” lands plane after pil... by mmh0000 on Wednesday May 11, 2022 @02:33PM (#31343968)
According to the Utah government's Drivers Handbook[0] (printed page 27, or PDF page 36), they recommend a 2 second distance on clear dry roads:

following distance Watch when the rear of the vehi- cle ahead passes a sign, pole, or any other fixed point. Count the seconds it takes you to reach the same point (one-thousand-one, one-thousand-two.) You are following too close if you pass that point before counting two seconds. Slow down and check your new following interval. Repeat until you are following no closer than two seconds. Always increase your following distance on slick roads, when following large vehicles, motorcycles, or vehicles pulling a trailer, at night, in fog, in bad weather and when following vehicles that stop at railroad crossings (transit buses, school buses or vehicles carrying dangerous mate- rial.)

[0] https://dld.utah.gov/wp-content/uploads/sites/17/2022/01/Dri...

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Re:Passenger with “no idea how to fly” lands plane after pil... by NovemberWhiskey on Wednesday May 11, 2022 @01:54PM (#31343480)
Please point me to the safety guidelines that say to keep 3 car lengths behind on the highway!

The most common guideline I've heard is the two-second (or sometimes, three-second) rule; that's roughly 54m at 60mph, assuming two seconds.

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Re:Passenger with “no idea how to fly” lands plane after pil... by stouset on Wednesday May 11, 2022 @01:59PM (#31343554)
> Usual safety guidelines are to stay about 3 car lengths behind whoever you're following

Uh, no. Usual safety guidelines are to stay a speed-dependent distance behind whomever you're following. The one I've heard most often quoted is one car length per ten miles per hour, so at 70mph you should be a minimum of seven car lengths behind.

Three lengths is comically short for those kinds of speeds.

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Re:Passenger with “no idea how to fly” lands plane after pil... by cecilpl2 on Wednesday May 11, 2022 @01:54PM (#31343467)
> Usual safety guidelines are to stay about 3 car lengths behind whoever you're following

No, safety guidelines are to follow 3 SECONDS behind the car in front, which is about 100m at 70mph.

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