Simplification 1

I have been trying to find the simplest way to define the rules of the game...

I have been abled to reduce it down to one sentence...

"Drive the fastest constant reasonably safe speed possible given the conditions."

I'm sure that I shall be able to make this reasonably more complex in the future. Don't worry.

Some notes:

Safe

Safe means that you never (ever) have or cause an accident. Accidents disqualify you from ever playing the game again in your life time. The only way to be requalified to play Traffic is to never (ever) have or cause an accident.

Constant Speed

Certain wave forms and conditions make a constant speed impossible. A perfect example of a good constant speed environment is East San Francisco California Bay Area traffic. In this traffic it is possible to maintain a constant 5mph at almost any time of the day, even in the worst traffic. Ho Chi Minh City Vietnam has some periods where a constant speed is not only impossible, it simply wouldn't be fun!!!

Conditions

Conditions are very variable. For example in Vietnam there are no stretches of highway that aren't also a potential resting point for children, chickens, dogs, pot holes, etc. that allow for a reasonable safe speed of more than approximately 80km/hr.