Are there any trains or vans?
Yes, there is a train.
   src        edge_attr  dst
0    1  to the right of    9
1    1  to the right of    8
2    4  to the right of    6
3    6   to the left of    4
4    8   to the left of    1
5    8   to the left of   10
6    9   to the left of    1
7   10  to the right of    8