What vehicle is it?
The vehicle is a train.
    src        edge_attr  dst
0     1   to the left of   18
1     1   to the left of   10
2     1   to the left of    9
3     2  to the right of    8
4     2   to the left of    4
..  ...              ...  ...
60   18  to the right of    1
61   18   to the left of   11
62   18   to the left of   17
63   19   to the left of    6
64   19   to the left of    3

[65 rows x 3 columns]