why do people block you from pulling out?

[V8XTasy]

I don't know if it's the norm, but I've noticed on many occasions that people just won't let me or other people pull out of a side road even when they are stopping for lights or a round about ahead anyway.
eg. a road I often use through my housing estate, some cars turn right at the end, having to cross over 2 lanes of traffic to get to the other side, it's quite a difficult manouvre and a busy road. The cars on this side are stopping for the queue at the lights anyway. I've seen people pulling out half way across the road waiting for a gap on the other side and cars will come right up to them beeping and swearing, even though they need to stop a car length ahead for the queue at the lights and in a few seconds the car will be gone.

And this morning, I was trying to pull out of a side road to turn right into traffic on the other side. I know I don't have right of way, so I wait for a gap, but no chance, it's a queue of traffic for the round about a few metres ahead. So I have no choice but to edge out, trying to make eye contact, hoping someone will let me in. But no, people go to the extreme to prevent me from joining the queue, to the point that one guy drove on the pavement to get around my front end then stopped to prevent me from joining, preferring instead to force me to block the other lane with my rear end.

I know there's no law to say let people in and I'm certainly not aggressive to push out into traffic as soon as I get to a junction, I try to wait for a gap, but sometimes there's no choice. I can't understand this insistence of preventing anyone from pulling out whether they're going to be in front or just crossing to the other side of the road, preferring instead to block their path and put them in danger of a collision from other traffic.

Maybe it's just me, but sometimes, if someone is trying to get out of a very difficult junction, particularly if they are already halfway across the road and in a precarious situation and I'm stopping metres ahead anyway, I would not purposely stop in front of them and block their way or act aggressively (unless it was your typical common whore driver pulling out of a junction without looking or stopping!! LOL).

What are other peoples thoughts? Should people be forced to wait in side roads until the road is completely clear or reverse up and take another route, for the sake of stopping for a few seconds to let them out?