In the city, eliminate the yellow light. Instant red, instant green. Tickets with heavy fines, like $1000 if you don't stand on the gas within 1 second of light turning green if you are first in line, and 1 second of the car in front of you moving if you are not first in line. Same fine for not not reaching and maintaining the speed limit within 5 seconds of green light. No tickets for speeding allowed, only for going under the limit. All stop lights to have either no left turn, or a turn lane so straight ahead traffic can flow. Rear ending someone who did not maintain the speed limit in the traffic lane is the fault of the one who got hit, not the hitter, with big fines and damage liability.
On the freeway system, just remove the brakes from all cars on the entrance ramp. All traffic congestion is caused by drivers who use the brakes when they should have used the gas. If you take away the brakes, they will HAVE TO hit the gas to they don't get rear ended, they will HAVE to merge properly with that gas instead of the brakes for their own safety. Hemi Joels fantasy world, where everyone knows how to drive.