Comparison of overall vs individual vehicular delay using macroscopic routing

In this paper, a macroscopic routing method is applied to two different traffic routing scenarios. The macroscopic method seeks to route vehicles in such a way that minimizes the travel time for the entire transportation network, while a traditional routing method seeks to minimize an individual’s travel time. This method was applied to a model road network that represents a real portion of the highway system in Los Angeles County. Data gathered from the California Department of Transportation creates a relationship between the number of vehicles on those highways to the speed that those vehicles are traveling. A program was created that uses that data to generate an optimal routing scenario for the entire traffic network when given a certain number of vehicles on the roadway. The results from this program show that taking some vehicles off of their fastest path, and putting them on a slower path, can save time and reduce congestion for the entire network. The congestion reduction achieved in the two scenarios tested by this program is about 90% depending on the number of vehicles on the network. Additionally, the total travel time for the entire network is reduced by as much as 35% in these scenarios. Finally, the results show that all vehicles, even the ones rerouted onto slower paths, experience a shorter travel time than they would have on the original, congested path. It should be noted that all of these results were obtained using a program that has a number of limitations, including being unable to account for congestion build-up over time.