[baldfat]

We have traffic due to lack of scientific understanding. http://www.science20.com/gerhard_adam/driving_traffic_and_tw...

Traffic = Flow Rate (How many cars pass per minute pass a specific point)

Traffic Solution is maintain proper distance. 2 seconds in good weather and 4 seconds when hazardous or 10 seconds when extremely unsafe weather/conditions.

When people increase the distance between cars during traffic causes the traffic behind to eventually come to a stop.

[lotsofpulp]

Thats why at any given speed, there is a maximum capacity of any road that when surpassed causes traffic, i.e. people speeding up and slowing down due to differences in each other's acceleration. This is unavoidable and the only solutions involve increasing everyone's speed, reducing # of vehicles, or making the road bigger.

[baldfat]

Traffic happens when distances are increased. Someone sees a slight slow down and they then slow down and give 20 seconds of space (I have seen cars and trucks give 200+ feet of distance for some odd reason. Then the flow is cut down to 10 cars a minute instead of 120.

[lotsofpulp]

Yes, but you can't fix that. And the faster you go, the longer it takes to stop (to the power of 2). Rule of thumb I've read is 1 car length for every 10mph to be able to stop in time in case if accident up ahead.

Obviously safety gets triaged with need to get somewhere in a reasonable amount of time, but at a certain point you hit a maximum and since we can't drive in unison, there will be a rubber banding effect.