The drivers should be free to drive more slowly in the slow lanes, more quickly in the fast lanes (up to the acceptable speed limit, of course, which is chosen by the drivers' freely elected representatives). Drivers should be free to pay more for the right to drive in a faster lane. The cops policing the traffic must be appointed by the government freely chosen by the drivers. The drivers should be free to decide through their chosen representatives to add more lanes, reduce lanes, charge tolls for using faster lanes, etc.

I think the bottom line is that if the drivers have freedom to organize and express themselves, and freely elect governing reprentatives, the traffic will take care of itself.