Depth Perception

I was watching a street today, which runs in front of a shop in a small town. There is a traffic light at the end of the street. People were stopping at the red light halfway up the block, instead of going to the corner. Was it because they couldn't see the light from the corner? Maybe, but it was still strange. I got to thinking about it. Maybe they couldn't judge the front of their car to the corner. That would be pretty disturbing. I was reminded about something I was told, when I took driving lessons. The teacher told me to match the end of my hood to the back wheels of the car in front of me, and then I would be correctly behind the car in front of me. My father was a notorious tailgater. It used to scare my Mother. I once was in the car with my freshman roommate in college. We were going up the interstate and getting on the tail of the cars in front of us. I asked him what if the guy in front of us panicked and put on the brakes. He said that we would just fly over him and keep going. But, conversely, why do some drivers insist on being so far back from the guy in front of them? That really bothers me. Do they have a slow reaction time, in case they need to brake? That is hard to say, but I just think they have a depth perception problem. Whatever it is, please either speed up or get in the slow lane, so I can go around you. Thank you.