Three new heuristic algorithms for the fleet size and mix green vehicle routing problem

In recent years, great efforts have been made to reduce greenhouse gas emissions by vehicles. petroleum products produce green house gas emissions; therefore reducing the use of these products can make a major contribution to reducing pollution. the fleet size and mix vehicle routing problem is one of the most widely used routing branches.in this problem, there are vehicles with different capacities and there is the possibility of choosingvehicles of different types. in this paper, fleet size and mix vehicle routing problem is death(?)consideringthe reduction of fuel consumption. since this problem is nphard, three novel heuristic methods entitled gros-i, gros-ii, ggtare presented for the problem. in order to evaluate the proposed heuristics a number of small, medium and large problems are solved. the results show that proposed algorithms have good performances.