CityTraffic is a plug-in for 3ds Max which helps to create car traffic flow on the roads and off-roads.

Special road editor and automatic cars setup substantially accelerates preparation of scenes for the simulation of traffic movement.
Huge variety of configurations for each car, whether it is adjustment of a suspension bracket or style of driving, give the ability to create realistic simulation.
Dynamics calculation makes movements on complicated surfaces more realistic, and the artificial intelligent system helps cars to operate independently.

http://rendering.ru/ru_en/plugins/citytraffic.html