Which vehicle is this, a bus or a train?
This is a train.
    src        edge_attr  dst
0     0   to the left of    4
1     0   to the left of   17
2     0   to the left of   16
3     0   to the left of    8
4     0   to the left of    1
..  ...              ...  ...
73   17  to the right of    9
74   17   to the left of   13
75   17  to the right of    0
76   18   to the left of   14
77   18  to the right of    8

[78 rows x 3 columns]