# turnouts don't care about the actual curvature,
# just make sure pos is for on()
#
# tn.off()  
#   \      / pos
#    \    /
# neg \  / tn.on()
#      \/
#       |
#       |
#       | root
#
#
#id rootid rootend posid posend negid negend
0   9      1       11    0      10    0
1   1      0       9     0      2     1
2   4      0       5     0      1     1
3   4      1       7     0      3     0
4   3      1       10    1      2     0
5   11     1       12    0      13    0