The stop sign is on what?
The stop sign is on the fence.
    src        edge_attr  dst
0     0               on    3
1     0   to the left of    5
2     0  to the right of    1
3     1               on    6
4     1   to the left of    0
5     1   to the left of    3
6     2   to the left of    3
7     2               on    1
8     3               on    6
9     3  to the right of    1
10    3   to the left of    5
11    3  to the right of    2
12    5  to the right of    3
13    5  to the right of    0
14    5               of    6
15    7               on    1