Number of nodes 20 Number of required arcs 28 Number of non required arcs 28 Capacity of vehicles 94 Number of vehicles 3 For required arcs (i, j) i j slopes length min service cost demand arc middle 0 1 -1 1 24 24 16 14.5 0 4 -1 1 90 90 7 48 1 0 -1 1 24 24 17 14.5 1 2 -1 1 31 31 14 41.5 2 6 -1 1 34.4 34.4 10 41.5 3 4 -1 1 18.2 18.2 6 84 4 3 -1 1 18.2 18.2 4 84 4 8 -1 1 38.4 38.4 17 81 5 9 -1 1 66.1 66.1 14 48 6 1 -1 1 14 14 8 26 6 5 -1 1 13 13 5 20.5 7 6 -1 1 28.2 28.2 18 39 8 3 -1 1 33.5 33.5 12 72 8 7 -1 1 18 18 6 60.5 8 9 -1 1 13.8 13.8 1 75 8 12 -1 1 31.4 31.4 6 59.5 9 4 -1 1 25.9 25.9 6 87 10 5 -1 1 23 23 14 8.5 10 14 -1 1 82.3 82.3 16 42.5 11 10 -1 1 25 25 12 14.5 12 11 -1 1 30.4 30.4 18 38.5 12 16 -1 1 34 34 9 35 13 8 -1 1 14.8 14.8 6 74 13 12 -1 1 32.2 32.2 10 64.5 13 14 -1 1 11.7 11.7 7 81 17 16 -1 1 28.6 28.6 10 33 18 13 -1 1 24 24 11 75.5 19 18 -1 1 24.7 24.7 1 84 For non required arcs (i, j) i j length 1 5 13 2 1 31 2 3 22.2 3 2 22.2 3 7 45.2 5 0 18.4 5 6 13 6 7 28.2 6 10 26.8 7 2 26.4 7 11 25 9 8 13.8 10 11 25 11 6 10 11 12 30.4 11 15 40.8 12 7 19.1 12 13 32.2 14 9 29 14 13 11.7 15 16 14 16 11 36.6 16 15 14 16 17 28.6 17 18 26.4 18 17 26.4 18 19 24.7 19 14 22.2