What do both the sign and the pole have in common?
The material, both the sign and the pole are wooden.
    src        edge_attr  dst
0     0               on   16
1     0   to the left of    8
2     0   to the left of    2
3     0   to the left of   15
4     1   to the left of    6
5     1  to the right of   16
6     1   to the left of   11
7     2  to the right of   16
8     2  to the right of    9
9     2  to the right of    0
10    6  to the right of    1
11    6  to the right of   16
12    7  to the right of   11
13    8  to the right of   16
14    8  to the right of    0
15    8  to the right of    9
16    9   to the left of    2
17    9   to the left of    8
18   10  to the right of   16
19   11  to the right of    1
20   11  to the right of   16
21   11   to the left of    7
22   12  to the right of   15
23   13  to the right of   16
24   15  to the right of    0
25   15   to the left of   12
26   15  to the right of   16
27   16   to the left of    6
28   16   to the left of    2
29   16   to the left of    1
30   16   to the left of   11
31   16   to the left of    8
32   16   to the left of   15
33   16   to the left of   13
34   16   to the left of   10