The biggest traffic problem is drivers who drive under the speed limit.
Speed limits are created to help traffic flow properly. When someone drives slowly, especially in the left lane, it has a compounding effect by slowing down trailing traffic.
I read a traffic engineering study a number of years ago that supported this.
I think that there should be a massive public awareness campaign to educate drivers to drive the speed limit, with appropriate space between cars, and not to drive slowly in the left lane.
Robert J. Merlin,