I'm careful not to. They give a lot of tickets where I live and on the roads I drive on. One of my sons has had hundreds of dollars of tickets in the last couple of months and he never had tickets before in his life. He is 27.
My son that is 21 and I just drive slow. I've told him if he has to be late to work or somewhere just be late. His work understands and gives people that are usually on time 5-10 mins extra to get there. There are red light cameras and speed traps. By schools you have to go 15 mph, even when you can't see the school! It's crazy. I think they are trying to run the city on speeding tickets.
All the time, as long as the weather's clear and there's no traffic or other stuff going on prohibiting it. Should probably specify - that's out of town, on the highways & blacktops. In town I pretty much stick to the speed limit.