Are there either buses or cars?
Yes, there is a bus.
    src        edge_attr  dst
0     0  to the right of   17
1     0  to the right of   12
2     0  to the right of    9
3     2   to the left of   15
4     2  to the right of    8
..  ...              ...  ...
60   17  to the right of    8
61   17  to the right of    9
62   17   to the left of    0
63   18   to the left of   12
64   18   to the left of    4

[65 rows x 3 columns]