Which kind of vehicle is this?
This is a truck.
    src        edge_attr  dst
0     1   to the left of   12
1     3      in front of   14
2     4   to the left of    9
3     4  to the right of   10
4     5  to the right of   13
5     5  to the right of   10
6     8   to the left of   12
7     9  to the right of    4
8     9  to the right of   10
9    10   to the left of    5
10   10   to the left of    9
11   10   to the left of   12
12   10   to the left of    4
13   12         sniffing   11
14   12  to the right of   10
15   12               in    3
16   12  to the right of    8
17   12  to the right of    1
18   13   to the left of    5
19   15               of    3