The rules for driving demand to keep at least enough distance to the vehicle before you, that you can safely perform an emergency break, if the vehicle should do so too.
In driving ed i learned that you need to keep at least 2seconds distance to the car in front of you, one second to react and one second to perform a similiar break maneuver like them. If your vehicle is heavier you need to increase that distance.
Whenever i drove like this the only result was people taking it as an invitation to swear in between the car in front of me and me. I want undercover cops in plain cars to just drive and record everyone violating the safe distance or takeing the space that is left as safe distance. We could resolve muncipal debt and drop the amount of deadly accidents by at least 50% this way.
Canada used to recommend 1 car-length for every 10 miles per hour. Along with metrification, that was changed to 2 seconds, but it's been set at 3 seconds for a long time.
I've yet to drive in traffic where even 1.5 seconds is manageable. More space than that and some slips into the gap, even if that leaves something like a loaded tractor-trailer hanging a second off their rear bumper.
This has the way. A god strategy to minimize the probability of an accident is to never move at all. Someone else might still hit you though, but that’s their fault.