What is the road made of?
The road is made of concrete.
    src        edge_attr  dst
0     0               of    4
1     0  to the right of   10
2     1               of    4
3     2               of    4
4     3               of    4
5     3  to the right of    9
6     3  to the right of    7
7     4          wearing    7
8     4      standing on    8
9     5               of    4
10    6  to the right of    7
11    6  to the right of    9
12    7               of    4
13    7   to the left of    6
14    7   to the left of    3
15    9   to the left of    6
16    9   to the left of    3
17   10               of    4
18   10   to the left of   11
19   10   to the left of    0
20   11  to the right of   10