What are the vehicles on the road?
The vehicles are cars.
    src        edge_attr  dst
0     0               on    5
1     0  to the right of    3
2     1   to the left of    4
3     1   to the left of    2
4     1   to the left of    3
5     2   to the left of    3
6     2  to the right of    1
7     3  to the right of    2
8     3  to the right of    1
9     3   to the left of    5
10    3   to the left of    0
11    4  to the right of    1
12    5  to the right of    3