Do you see a traffic light there?
Yes, there is a traffic light.
    src        edge_attr  dst
0     0  to the right of   10
1     0   to the left of    5
2     1               on    9
3     1   to the left of   11
4     1   to the left of    6
5     1   to the left of    2
6     2  to the right of    1
7     5  to the right of   10
8     5  to the right of    0
9     6               on    9
10    6  to the right of    1
11    8               on   13
12    9  to the right of   10
13    9  to the right of   12
14   10   to the left of   14
15   10   to the left of    9
16   10   to the left of    5
17   10   to the left of    0
18   11  to the right of    1
19   12   to the left of   13
20   12   to the left of    9
21   13  to the right of   12
22   14  to the right of   10