Crowd Path Following steering behavior

In this demonstration, 30 vehicles exhibit crowd path following behavior. The path following technique is the same as used in this single vehicle demonstration. In addition, the behavior seen here includes separation steering behavior which serves to keep the vehicle from clumping together. In this example, the two component behaviors (path following and separation) are combined using a simple weighted sum, with path following given about three times the weight as separation. The individual vehicles have slight variation in their maxSpeed parameter, so the top speed of the fastest is about 5% faster than the slowest. Finally, in addition to the steering behaviors, the vehicle's motion is subject to a kinematic non-penetration constraint which prevents them from overlapping. This gives an impression of solid objects which can bump and jostle each other, but the simplistic model of these interactions used here is not physically-based.

From
Steering Behaviors for Autonomous Characters