What kind of vehicle is on the street?
The vehicle is a train.
    src        edge_attr  dst
0     1               on    8
1     1  to the right of    4
2     1  to the right of    2
3     1  to the right of   11
4     1  to the right of    7
5     2   to the left of    6
6     2   to the left of    1
7     3  to the right of   11
8     3  to the right of   15
9     3           behind   16
10    4   to the left of   11
11    4   to the left of    1
12    5  to the right of    6
13    5  to the right of   10
14    5  to the right of   14
15    5  to the right of   11
16    6  to the right of   11
17    6  to the right of   14
18    6   to the left of    5
19    6  to the right of    2
20    7   to the left of    1
21    7   to the left of   12
22    7   to the left of   13
23   10   to the left of   14
24   10   to the left of    5
25   11   to the left of   15
26   11   to the left of   13
27   11   to the left of    3
28   11   to the left of    1
29   11   to the left of   12
30   11   to the left of   14
31   11   to the left of    5
32   11   to the left of    6
33   11  to the right of    4
34   12  to the right of   11
35   12  to the right of   15
36   12  to the right of    7
37   13  to the right of   11
38   13  to the right of   15
39   13  to the right of    7
40   14  to the right of   10
41   14   to the left of    5
42   14   to the left of    6
43   14               on    9
44   14  to the right of   11
45   15  to the right of   11
46   15   to the left of   13
47   15   to the left of   12
48   15   to the left of    3
49   16      in front of    3