The bigger problem is that many people are simply not aware of other drivers on the road.
You need to pay attention to the flow of traffic, and adjust your speed to match the majority of drivers on that road. You need to regularly watch your mirrors and change lanes to allow faster drivers to pass you. And you need to merge at the posted speed limit - to enter the highway going slower than the flow of traffic is dangerous.
I'm by no means a maniac on the road, but I do like to drive slightly faster - I agree with the posters who cite getting there more faster. On a highway with a posted speed of 90km/h, I drive 100-110km/h. If someone is doing 85-90 in the left lane, I will put my foot down and pass on the right. But if I'm doing 110 in the left lane and someone comes barreling up behind me at 120+, I'll switch lanes and let them through.
Courtesy is apparently a lost art.