It seems you have the impression that the problem with congestion is that cars aren't driving fast enough. But my impressions is that you can't reduce congesti

It seems you have the impression that the problem with congestion is that cars aren't driving fast enough. But my impressions is that you can't reduce congestion by going faster. In fact, you can get more congestion by going faster. For instance, imagine a bottleneck of cars passing an accident, where they all drive 60km/h instead of 80km/h. If there's a lot of cars on the road you get a wave of congestion in front of accident. But if everyone had been going 60km/h anyway, there wouldn't have been a wave. You also have related studies showing that if equally spaced cars drive around in a circle, and they try driving over a certain speed (related to spacing) you invariably get waves of congestion, despite the fact that it should theoretically be possible to drive without waves at any speed. Normal humans simply don't regulate speed fast enough. It's kind of besides the point though, because driving slower wouldn't get more cars through per hour. The point is just that speed on the highway isn't an important factor. Perhaps if you look at speed on off-ramps and through the following intersections you'd get to something interesting.. but then safety becomes more critical.