Are there either vans or trains?
Yes, there is a train.
     src        edge_attr  dst
0      0   to the left of   16
1      0   to the left of   23
2      0  to the right of    2
3      0   to the left of    1
4      0  to the right of   12
..   ...              ...  ...
110   27  to the right of   17
111   27  to the right of   19
112   28  to the right of    3
113   28  to the right of    2
114   29   to the left of   27

[115 rows x 3 columns]