What vehicle is blue?
The vehicle is a bus.
    src        edge_attr  dst
0     3   to the left of    8
1     4               of    7
2     4               on    7
3     5  to the right of    7
4     5               on    6
5     6  to the right of    7
6     7               on    0
7     7   to the left of    6
8     7   to the left of    5
9     8  to the right of    3
10    8               on    6