Two eco-routing algorithms, one optimized for shortest path and one optimized for fuel consumption, were developed at the University of Idaho.
Nationwide, United States
Developing and Field Implementing a Dynamic Eco-Routing System
Summary Information
The study developed two eco-routing systems and used them to investigate and quantify the system-wide impacts of implementing an eco-routing system. The first algorithm enhanced previous eco-routing applications by introducing ant colony optimization (ACO-ECO) strategies. The other algorithm, the Linear Programming Feedback Eco-routing System (LPS-ECO) utilized fuel consumption feedback and considered road capacity along with current traffic conditions to load-balance the traffic to reduce congestion and minimize fuel consumption and emissions.
Methodology
Ant colony optimization is a meta-heuristic iterative technique inspired by the foraging behavior of some ant species. In the ant colony, ants walking to and from a food source mark the path to be followed by other members of the colony. The shorter the path, the more marks on that route, and consequently, the preferable this route is. In the ACO-ECO algorithm, vehicles are employed as artificial ants, the mark is the inverse of the fuel consumption cost for each link. Each artificial ant periodically deposits their mark by updating the fuel consumption cost for the link it is traversing.
The proposed linear programming stochastic-based eco-routing technique (LPS-ECO) tries to minimize the network-wide fuel consumption but guarantee route continuity for each individual traffic flow by using all the available network resources (roads) toward the destination. The flow balance at a given intermediate node means that the summation of the traffic entering that node equals that exiting it. The combination of the objective function and the individual flow balance at each node guarantees the route continuity.
Findings
ACO-ECO reduces the network-wide fuel consumption and Carbon dioxide emissions by 2.3 to 6.0 percent. LPS-ECO reduces fuel consumption by 38 percent.