What is common to the pole and the sign?
The material, both the pole and the sign are metallic.
    src        edge_attr  dst
0     0             near    1
1     0          next to    2
2     0               on    1
3     0             near    2
4     0  to the right of    5
5     0          next to    1
6     1             near    0
7     1             near    2
8     2             near    1
9     2             near    0
10    2  to the right of    3
11    3   to the left of    2
12    3               on    2
13    4   to the left of    5
14    5   to the left of    0
15    5  to the right of    4