You mean drivers following too closely behind the car in front?
As you're a cyclist, and by the sounds of it one who uses cycle paths, you'll be aware of the state of most of the cycle paths. The ones that are less than ten metres long,. The ones which swerve up and down pavements. The ones that are faded so much you can hardly see them. The 'safe' ones which are separated from the road by a kerb, then never swept and are full of pebbles and debris, so it's like riding on marbles.
Don't get me wrong, I ride a bike, but I'm not some sort of cycling evangelist. I do drive HGV's for a living and see a lot of bad drivers in/on all sorts of transport. Due to the sheer volume, the majority are car drivers. No idea if it's proportional though.