What is the vehicle that the cones are behind of?
The vehicle is a bus.
    src        edge_attr  dst
0     0   to the left of   20
1     0   to the left of   16
2     0   to the left of    7
3     0   to the left of   15
4     0  to the right of   12
5     1  to the right of   13
6     3  to the right of   10
7     3  to the right of    9
8     4   to the left of   20
9     4      in front of   18
10    4   to the left of    7
11    4   to the left of    8
12    4   to the left of   15
13    4   to the left of   16
14    4  to the right of   18
15    5               of    7
16    7  to the right of   18
17    7  to the right of    4
18    7  to the right of   12
19    7  to the right of    0
20    8       mounted on   20
21    8  to the right of    4
22    9   to the left of    3
23   10   to the left of    3
24   12               of    4
25   12   to the left of    7
26   12   to the left of   15
27   12   to the left of    0
28   13   to the left of    1
29   14   to the left of   20
30   15  to the right of    0
31   15  to the right of    4
32   15  to the right of   12
33   16  to the right of    4
34   16  to the right of    0
35   18           behind    4
36   18   to the left of    7
37   18   to the left of    4
38   19   to the left of   20
39   20  to the right of    0
40   20  to the right of    4
41   20  to the right of   19
42   20  to the right of   14