In mode choice, trips are assigned to a mode (usually auto or transit) based on what's available in a particular zone, the characteristics of the household within that zone and the cost of the mode for each mode in terms of money and time. Since most trips by bicycle or walking are generally shorter, they are assumed to have stayed within one zone and are not included in the analysis. Finally, in route assignment, trips are assigned to the network. As particular parts of the network are assigned trips, the vehicle speed slows down, so some trips are assigned to alternate routes in such a way that all trip times are equal. This is important because the ultimate goal is system-wide optimization, not optimization for any one individual. The finished product is traffic flows and speeds for each link in the network.
In mode choice trips are assigned to a mode (usually auto or transit) based on what's available in a particular zone the characteristics of the household within that zone and the cost of the mode for each mode in terms of money and time Since most trips by bicycle or walking are generally shorter they are assumed to have stayed within one zone and are not included in the analysis Finally in route assignment trips are assigned to the network As particular parts of the network are assigned trips the vehicle speed slows down so some trips are assigned to alternate routes in such a way that all trip times are equal This is important because the ultimate goal is system-wide optimization not optimization for any one individual The finished product is traffic flows and speeds for each link in the network