How far do you travel blind?
Guess first. Then test your own reaction time, and use it in a crash test with the car in front.
Test your reaction time
Tap the circle the moment it turns red, like brake lights ahead. Three tries.
Following-distance crash test
The car in front brakes as hard as it can. You brake as hard as you can too, but only after your reaction time. Pick a speed and a gap, then hit brake.
What keeps you safe
Put it on do-not-disturb or in the glovebox. Using a phone while driving is fined in the UAE, and a 2-second glance at highway speed covers more than half a football pitch.
Pick a sign the car in front passes and count. If you reach it before "two", drop back. Use more in rain, dust or at night. Tailgating is also fined.
Even the fastest reaction can't fix a short gap. Both cars brake equally hard, so the only thing that saves you is the distance you left.
Drowsiness slows reaction as much as alcohol. Pull over somewhere safe and rest.
The physics is simplified: hard braking of about 7 m/s² on a dry road and 5 m/s² on a wet one, both cars braking equally hard. Real cars, tyres and roads vary. Always follow posted speed limits and the police's guidance.