Are there ambulances or trains?
Yes, there is a train.
     src        edge_attr  dst
0      0  to the right of   27
1      0   to the left of   12
2      0  to the right of   13
3      1  to the right of   27
4      1   to the left of    8
..   ...              ...  ...
151   26  to the right of   14
152   26  to the right of   27
153   27   to the left of    1
154   27   to the left of    0
155   27   to the left of   26

[156 rows x 3 columns]