I've seen people teach that you should leave a car length in front of you when stopped. I think that was mainly for cases like what karma described. I was just taught to be able to see their wheels on the pavement. I stop a little further back than that though. I make sure I have enough room to whip out of the lane quickly in case it turns out there's a stalled car up ahead. Bumper rapers get trapped by shit like that if there's not someone like me around who can make room for you to back up. Not to mention getting fucked by people driving sticks. The fact that there are fewer sticks on the road these days just means that the people driving them likely don't have as much practice. If someone in a stick rolls back into you, the burden of proof is on you to prove you didn't rear end them.
Anyway, I don't see what you're seeing, but my money would be on the people texting or leaving room for someone to get over. There's only one place on my daily drive where people regularly leave 1+ car lengths at a light, and it's a spot where 75% of the people getting off at the exit are trying to get all the way over to the right within about 100 or 200 yards.
Yeah, I get all that, and I said a reasonable distance is fine. However, 1+ car lengths is not a reasonable distance. If anyone rolls back over an entire length of a vehicle, they don't deserve to have a driver's license, and in fact won't get one if they exhibit that kind of ineptness. Again, if you're in fucking San Francisco and on one of those insane hills (assuming it isn't covered in feces), I'd give somebody a huge distance in case they have a stick. This is in the middle of Sacramento surface streets, flat as Bree Larson's ass, there's just as much chance they roll forward as backward. And there are, at any given time, dozens of cars stopped in front and behind you. If someone plows into the back of the line and Human Centipede's the entire line all the way up to your car, and you save the car in front of you because you had all that space, well then you got me I guess.
Of course driveways and side streets you leave room. That's clearly not what I'm talking about. I have to make a left in front of traffic every day to get to work, and sometimes I have no opportunity at all until the cars are backed up and people are polite enough to leave a gap. I am all about returning those kinds of courtesies at every opportunity. It is a separate jimmy rustler when someone doesn't give a fuck and blocks me in those situations and then pretends they can't see me screaming at them about how fucking retarded they are. I'd never purposely be the blocking person in those situations.
These are stationary, nobody is fucking moving, nobody is turning, nobody is abruptly changing lanes because all the other lanes are just as backed up as yours. If everyone left 1+ car length between them, a) some jackhole would just fill it via changing lanes thinking they are getting ahead, and b) traffic would take twice as fucking long to get through because of the accordion effect at stop lights, and only half as many cars would make it through each light. Sure, if a car suddenly stalls out you're fucked, but at that point, in this kind of traffic, everyone is fucked at that point anyway. Leaving room for 1 in a 1000 events is a waste of everyone's time. You might as well just ride your bike everyday, just in case your car would have caught on fire.
And it isn't people texting, or leaving room just in case people want to get over. Since it is bumper to bumper traffic, I can see them do it over the period of many lights, and they are consistent. They are either terrified of being too close when at a complete stop, or just retarded. They aren't even idling in neutral in a stick and slowly rolling forward, they are completely stopped. They aren't looking down texting (I'm sure some are, but so are the ones parked closer), they aren't beating their kids, they are purposely doing it every time, for no reason that I can fathom. And they are fucking morons, every one of them.
Listen, I am not going to blow my top over a car length. Ain't nobody got time for that. The ones I was initially referring to are typically much more than that. But realistically, if everyone did a car length, as I mentioned above, it would be fucking horrible too. There's no reason to be able to see their tires. Aside from the fact that if you're in a truck that distance is about 4 inches, versus a sports car is about 20 feet. Everyone that drives for awhile has a pretty good idea what is a decent distance and has no problem finding that sweet spot. Except these people. And they need to be murdered, live on television, so people stop doing it.
EDIT: Yes, I'm super bored on a Friday morning. Mostly all in good fun. But really, they need to die.