Which color is the car following the truck?
The car is gray.
     src        edge_attr  dst
0      0   to the left of    7
1      0  to the right of   14
2      0  to the right of   13
3      0   to the left of   21
4      0  to the right of   22
..   ...              ...  ...
107   22   to the left of   12
108   22   to the left of   11
109   22      followed by   21
110   22   to the left of    0
111   22   to the left of   21

[112 rows x 3 columns]