Characteristics of Laser Backscattering Intensity to Detect Frozen and Wet Surfaces on Roads

Table 3

Statistics of laser backscattering intensity for surface types at the 5 m distance.

Surface Type	Vegetation	Dry Asphalt	Wet Asphalt	Ice (Sidewall)
No. of sample points	471	535	323	148
Mean	244.43	206.56	131.49	132.33
Standard deviation	21.67	7.96	20.24	66.74
Minimum	200	189	82	78
Maximum	372	233	178	835