Are there any trains above the gravel?
No, there is a table above the gravel.
    src        edge_attr  dst
0     0  to the right of    8
1     0  to the right of    7
2     0  to the right of    9
3     2            above   10
4     3  to the right of    9
5     5  to the right of    6
6     6   to the left of    5
7     7   to the left of    8
8     7   to the left of    0
9     8   to the left of    0
10    8  to the right of    7
11    8   to the left of   10
12    9   to the left of   10
13    9   to the left of   11
14    9   to the left of    0
15    9   to the left of    3
16   10  to the right of    9
17   10            under    2
18   10  to the right of    8
19   11  to the right of    9