In an ideal world of no traffic, give ways, roundabouts, traffic lights, this works. In the real world, it doesn't.

There's a game I LOVE playing on the North Circular and the M1. It's called "catch the moron doing a gazillion miles per hour and weaving through traffic whilst taking my time" I generally win because I plan ahead, knowing how lights are synchronized, where traffic is, what lanes travel quickest, and how to vary my speed accordingly to make smooth and steady progress.