Do you see trains or buses that are not yellow?
No, there is a bus but it is yellow.
    src        edge_attr  dst
0     0  to the right of    5
1     0  to the right of    4
2     0  to the right of   28
3     0  to the right of   18
4     1  to the right of    9
..  ...              ...  ...
87   31   to the left of   10
88   32  to the right of    2
89   32  to the right of    7
90   32  to the right of   21
91   32  to the right of   31

[92 rows x 3 columns]