Which kind of vehicle is it?
The vehicle is a train car.
    src        edge_attr  dst
0     1   to the left of   12
1     1   to the left of   15
2     2          next to   11
3     2   to the left of   12
4     2   to the left of   11
5     2   to the left of   15
6     2   to the left of    8
7     2       hanging on   13
8     3  to the right of   10
9     4   to the left of    5
10    4   to the left of   11
11    4   to the left of    8
12    4   to the left of   15
13    5  to the right of    4
14    7               at    2
15    8  to the right of    2
16    8  to the right of   12
17    8  to the right of    4
18   10   to the left of    3
19   11  to the right of    4
20   11  to the right of    2
21   11     hanging from   13
22   11             near    2
23   12   to the left of    8
24   12   to the left of   15
25   12  to the right of    2
26   12  to the right of    1
27   15  to the right of   12
28   15  to the right of    2
29   15  to the right of    4
30   15  to the right of    1