Research Article
Solving the Tractor and Semi-Trailer Routing Problem Based on a Heuristic Approach
Table 1
The tractor running time between two depots (hours).
| | From | To | | H | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| | H |
0
|
5.5
|
4.0
|
4.5
|
1.5
|
1.0
|
1.0
|
4.0
|
3.0
|
4.5
|
1.0
|
3.5
|
3.5
|
3.0
| | 1 |
5.5
|
0
|
1.5
|
1.0
|
4.0
|
4.5
|
4.5
|
2.5
|
2.5
|
3.0
|
5.5
|
4.0
|
5.0
|
6.5
| | 2 |
4.0
|
1.5
|
0
|
2.5
|
2.5
|
3.0
|
3.0
|
4.0
|
3.0
|
4.5
|
4.0
|
3.5
|
3.5
|
5.0
| | 3 |
4.5
|
1.0
|
2.5
|
0
|
3.0
|
3.5
|
3.5
|
1.5
|
1.5
|
2.0
|
4.5
|
3.0
|
4.0
|
5.5
| | 4 |
1.5
|
4.0
|
2.5
|
3.0
|
0
|
0.5
|
0.5
|
4.5
|
3.5
|
5.0
|
1.5
|
4.0
|
4.0
|
3.5
| | 5 |
1.0
|
4.5
|
3.0
|
3.5
|
0.5
|
0
|
1.0
|
5.0
|
4.0
|
5.5
|
2.0
|
4.5
|
4.5
|
4.0
| | 6 |
1.0
|
4.5
|
3.0
|
3.5
|
0.5
|
1.0
|
0
|
4.0
|
3.0
|
4.5
|
1.0
|
3.5
|
3.5
|
3.0
| | 7 |
4.0
|
2.5
|
4.0
|
1.5
|
4.5
|
5.0
|
4.0
|
0
|
1.0
|
0.5
|
4.0
|
2.5
|
3.5
|
5.0
| | 8 |
3.0
|
2.5
|
3.0
|
1.5
|
3.5
|
4.0
|
3.0
|
1.0
|
0
|
1.5
|
3.0
|
1.5
|
2.5
|
4.0
| | 9 |
4.5
|
3.0
|
4.5
|
2.0
|
5.0
|
5.5
|
4.5
|
0.5
|
1.5
|
0
|
3.5
|
2.0
|
3.0
|
4.5
| | 10 |
1.0
|
5.5
|
4.0
|
4.5
|
1.5
|
2.0
|
1.0
|
4.0
|
3.0
|
3.5
|
0
|
2.5
|
2.5
|
2.0
| | 11 |
3.5
|
4.0
|
3.5
|
3.0
|
4.0
|
4.5
|
3.5
|
2.5
|
1.5
|
2.0
|
2.5
|
0
|
1.0
|
2.5
| | 12 |
3.5
|
5.0
|
3.5
|
4.0
|
4.0
|
4.5
|
3.5
|
3.5
|
2.5
|
3.0
|
2.5
|
1.0
|
0
|
1.5
| | 13 |
3.0
|
6.5
|
5.0
|
5.5
|
3.5
|
4.0
|
3.0
|
5.0
|
4.0
|
4.5
|
2.0
|
2.5
|
1.5
|
0
|
|
|
