Funny, last night I was finishing up a 20 mile ride and was going down a road that was 55 mph. all cars were giving me about 2' of space. I got to a long straight stretch and wanted to shake out the arms and legs a bit, so I looked back to see if there were any cars coming. None, so I took turns shaking my arms, etc. I was about done, bike was swerving a bit and I looked back again to see a car about a 1/4 mile away. I could here them slow down , then they totally moved into oncoming lane, must be they were a bit freaked to see me swerve around.