Which kind of vehicle is to the left of the train?
The vehicle is a truck.
     src        edge_attr  dst
0      0  to the right of    3
1      0  to the right of    9
2      0  to the right of   18
3      0  to the right of    4
4      0  to the right of    7
..   ...              ...  ...
144   19   to the left of    2
145   19  to the right of    1
146   19  to the right of    7
147   19  to the right of    9
148   19  to the right of   13

[149 rows x 3 columns]