Header header
Lane[] lanes

# Marks where you are amoung the lanes,
# for examples:
# -------------------------
# Lane:  0  1  2  3  4
#        |  :  |  :  |
# Car : A     B   C    D
# -------------------------
# The positions of cars above are:
# A = -0.5;
# B =  1.5;
# C =  3.0;
# D =  4.5;
# You can set NaN to position for unknown.

float64 position