What is the color of the water the bridge is over?
The water is gray.
    src        edge_attr  dst
0     0   to the left of    1
1     1  to the right of    0
2     2       covered by   19
3     3  to the right of    6
4     3  to the right of   22
..  ...              ...  ...
56   23  to the right of    6
57   25         crossing   11
58   26   to the left of    4
59   26   to the left of    5
60   26   to the left of   17

[61 rows x 3 columns]