Does anyone have a suggestion for or experience with open source traffic simulators in conjunction with Network Analyst? I would like to model a mass of cars going from one place to another with a condition for fuel need. So as the cars are going from their start to their destination, they are consuming fuel, and once they reach a certain minimum fuel remaining threshold, they find the nearest gas station and fill up. I am able to do this (in a very clunky way) with one car, however, it is inefficient and almost not doable when I start thinking about modeling hundreds or thousands of cars. Suggestions????