Some history.. Make what you want of it:
Proper following distance:
When I was in Driver's ED they taught one car length (20') for every 10 MPH as I recall (might be wrong) later they change it to "The time you travel in 2 seconds) much easier to gauge) and later still 3, 4 for large rigs (motor homes)
Later in life I went to work as a police dispatcher.. Well where the post was if I took my lunch break outside I could watch traffic on the freeway below.
Average following distance was the distance you travel in 1 second, and Read on
Then we moved the office twice, last move gave us over 150 Freeway cameras and often the best show on TV was the Freeway Follies.. Many were following at closer to 1/2 second.
Yes, Tailgating is a problem
Gas stove (Full size residential 4 Burner Kitchen range with oven) fell off a truck and landed in the second lane. We'd watch cars come up on it, all in the same lane, and all but the lead tailgating,, The first would change lanes at the last second and the next two... underwear
Finally 3 cars and a pickup
First changed lanes at last second
Second changed underwear
#3, I'm rather sure hit #2
And the pickup.. Did not stop, swerve or slow down. He place kicked that stove a good quarter mile and dropped it on the shoulder.
I called off the troopers I'd dispatched and called county back and re-seheduled pick up for the monrning and gave the updated location.