There are some really big hills on my way to work (5 miles each way) and I too am really scared of going fast download hill and brake constantly. I worry that even though I'm looking ahead for cars that they might not see me. I don't know what speed I ride. Working it out based on the distance and the time taken on my usual commute I would say it's around a snailspace of 8 mph.

I'm hoping as I get more experience and keep going I will eventually improve. I don't really want to push myself too hard to the point where I'm not enjoying cycling. I figure that after 20 years of not having touched a bike then just commuting to work is a pretty good start. I really enjoy commuting at a leisurely pace and it still works out faster than the bus I used to take.

I should probably add that my bike is definately not built for speed - it a cruiser sort of thing, that looks like the basic bikes everyone uses in Europe except the tyres are fat. I really love it and because it was cheap I'm not too precious about it.