What kind of vehicle is old?
The vehicle is a bus.
    src        edge_attr  dst
0     1   to the left of   13
1     1   to the left of    8
2     1  to the right of    3
3     2  to the right of   13
4     2   to the left of   10
5     2  to the right of    9
6     3   to the left of    4
7     3   to the left of    1
8     3   on the side of    9
9     4   to the left of   13
10    4   to the left of    8
11    4  to the right of    3
12    5            above    9
13    6            below    9
14    8   to the left of   10
15    8  to the right of    4
16    8   to the left of   13
17    8  to the right of    1
18    9             near   12
19    9   to the left of    2
20    9   to the left of   11
21    9   to the left of   10
22   10  to the right of   11
23   10  to the right of    9
24   10  to the right of    8
25   10  to the right of   13
26   10  to the right of    2
27   11  to the right of    9
28   11   to the left of   10
29   11  to the right of   13
30   12               on    7
31   12          next to    9
32   13   to the left of   10
33   13   to the left of   11
34   13  to the right of    1
35   13   to the left of    2
36   13  to the right of    4
37   13  to the right of    8