So, the car in front was able to swerve, but from 2 cars back, he couldn’t and ended up killing a person. Somebody wasn’t paying attention. Not they he’s unique in this, but his statement is baloney.
I can see how that is hard to react to.
I wasn’t sure how hard though, so I did a thought experiment.
Say there is 50m between each car, and they’re all driving 25m/s. First car starts braking at 5ms. After one second the distance between 1 and 2 is 45m. After two seconds, 35m. After 3s, 20m, and the car is evading. After 4s, car 2 is passing by 1, whom is now moving at only 5m/s. Car 1 is finally revealed to car 3, who now has a maximum of two seconds to do something before it crosses the 50m gap.
And that’s assuming an adequate gap. They were likely closer.
The "safe distance" is only "safe" if all the traffic is moving at least.
I don't understand the scare quotes around safe distance here. Maintaining safe distance (and the implied safe speed and open eyes) absolutely would help in these situations.
Safe following distance isn't predicated on defying physics, it means assume the car in front might stop dead for any reason - hitting an unseen obstacle, swerving to reveal an obstacle, sudden mechanical failure, animal collision, whatever. The distance you need to react and stop is around 100 metres at 70mph. Therefore, that's the distance you should keep from the car in front.
As a bonus, it gives any tailgaters more time to notice you're slowing down too. Hopefully this means you're less likely to get pancaked between two cars.
No, it's based on assuming the car in front might brake at standard non-physics-defying rates at any time. The 'safe' following distances that are advised don't allow for encountering stationary objects. That's why they're called following distances, as in, you're following another vehicle that obeys the laws of physics.
Maybe there truly wasn't enough time to completely avoid a crash. But there should have been enough time to avoid a serious (deadly) crash.
Imagine you're following - at a safe distance - a vehicle. The driver of the vehicle you're following doesn't notice that the car ahead of them is emergency braking. They notice at the last second and swerve around it to avoid a collision.
You are then face to face with a nearly-stationary object which was concealed from you by the vehicle ahead of you.
From your perspective, it fell from the sky. If you don't swerve, a collision is unavoidable.
I can't speak for the USA, but in the UK, if someone swerves and you rear end a stationary object, you are at fault. Indeed if you rear end another vehicle, you are nearly always at fault (unless e.g. they pulled in front of you then immediately slammed the brakes).
For stopping distances, this is what we are taught in the UK (rule 126): https://www.gov.uk/guidance/the-highway-code/general-rules-t...
Stopping distance at 70mph is about 100m and "The safe rule is never to get closer than the overall stopping distance". This is a minimum - in adverse conditions the distance should be even greater.
This means when you see the stationary object, you're about 100m away, which is adequate time to stop IF you're paying attention and your car is well maintained (we have annual MOTs to ensure this).
This assertion about following distance feels purely theoretical for busy freeways.
A lot of experienced drivers here claim it's impossible too, but there's a good way to know that it's not: on your driving test, you'll fail for following too closely, so most people manage to keep an adequate stopping distance for the test. Following closely is usually a habit picked up when someone becomes a more confident driver.
The real reason is probably people don't want to take the tiny average speed hit or find it unfair that they keep letting people in.
The driver of the third car claims there was nothing he could do. That's baloney, as the car that was EVEN CLOSER to the stopped Tesla was able to react. Fact is, he was following too close and/or not paying attention, and crashed.
Should have recognised something odd (a broken down car) within 1.5 seconds, leaving 1.5 seconds to slow down.
Applying brakes from 60mph would mean you'd still be traveling over 40mph when you hit the back of the car.
Thus you need to give more than 2 seconds if you can't see beyond the car in front
Drivers need to think of every vehicle as being in a moving block[1] signalling system with each block being ~290m long (actual vehicle in the middle of this block) in wet conditions at 110kmh-1[2] and ~230m long in dry conditions at 110kmh-1[2]. No vehicle should ever enter another vehicles moving block. Obviously the type of vehicle, tires, road surface material, etc can reduce (or extend) those required block lengths, but you generally have to assume worst case scenario because how are you to know whether another vehicle has bald tires or is operated by a person who is fatigued or distracted and taking much longer to respond than they should.
[1] https://en.wikipedia.org/wiki/Moving_block
[2] https://www.qld.gov.au/transport/safety/road-safety/driving-...