Is the ladder to the left of the traffic signal the sign is on?
Yes, the ladder is to the left of the traffic light.
    src        edge_attr  dst
0     1               of    9
1     1   to the left of    8
2     2  to the right of    5
3     2   to the left of    8
4     5               in    9
5     5   to the left of    8
6     5   to the left of    2
7     7               on    8
8     7  to the right of   11
9     8  to the right of    9
10    8  to the right of    2
11    8  to the right of    5
12    8  to the right of    1
13    9               on   10
14    9   to the left of    8
15   11   to the left of    7