What's the traffic sign on?
The traffic sign is on the pole.
   src        edge_attr  dst
0    0             near    4
1    0  to the right of    2
2    1               on    0
3    2               on    4
4    2   to the left of    0
5    3               on    0
6    4            above    4
7    4               on    0
8    4            below    4
9    4             near    0