On which side is the empty vehicle, the right or the left?
The trailer is on the right of the image.
    src        edge_attr  dst
0     0  to the right of    3
1     0  to the right of    1
2     1           behind    4
3     1   to the left of    3
4     1   to the left of    0
5     3  to the right of    1
6     3               by    4
7     3   to the left of    0
8     4      in front of    1
9     5               on    9
10    6   to the left of   10
11    7               by    9
12    9               on    6
13   10  to the right of    6
14   11               on    3