I’ll start. Stopping distance.
My commute is 95 miles one way to work, so I see a lot of the highway, in the rural part of the US. This means traveling at 70+ mph (112km/h) for almost the entirety of the drive. The amount of other drivers on the road who follow behind someone else with less than a car’s length in front of them because they want to go 20+ over the speed limit is ridiculous. The only time you ever follow someone that close is if you have complete and absolute trust in them, and also understand that it may not even be enough.
For a daily drive, you likely need 2-3 car lengths between you at minimum depending on your speed to accurately avoid hitting the brakes. This doesn’t even take into account the lack of understanding of engine braking…
What concepts do you all think of when it comes to driving that you feel are not well understood by the public at large?
For car distance I’ve seen 2-3 seconds start to be recommended, since people are not good at judging distance. So counting how long it takes to reach the same fixed point as the car ahead.
Car length per 10mph is much easier in my opinion. 2-3 seconds isn’t based on any speed so by itself is quite useless. Your car’s stopping distance changes with speed. It won’t always be 2-3 seconds. Let alone counting reaction time at higher speeds.
Seconds is based on speed though. It’s literally how speed is defined. Distance over time. At 60mph you travel 88 feet per second. So if you count out the seconds between when the car ahead passes say a road sign and you pass the same road sign and it’s two seconds, there’s roughly 176ft between your two vehicles. If you’re going 25 mph, then two seconds equates to 73ft of space.
Which really gives you more space than car lengths per 10mph, so it’s safer. 10mph=~14fps. The average length of a car is 14ft. So you end up giving double the space if you count out 2 seconds.
I cannot not think 14 frames per second when I see that.
The driver can only perceive 14fps
It is in fact, seconds. Not only is your own reaction time fixed, distance is speed × time so the distance you follow is farther, the faster your speed if you count out the same amount of time.
It works for all speeds, plus how do you know how far ahead 6 cars bumper to bumper is when you when going at highway speeds? The lines aren’t always a good tell.
It’s better to pick a bridge, a sign, an intersection or anything else interesting that the car in front passes, count 0-[x], 1-[x], 2-[x], 3… and so on where [x] is your favourite 4-syllable state or word. Count to 5 in a transport truck or in bad weather, count to 8 if driving a transport truck in bad weather.