Reliability-Based Analysis of Sight Distance Modelling for Traffic Safety

Table 3

Comparison of ASD values among the three models.

Group	ASD pair	Mean (m)	St. dev. (m)	value
All cases	2D-3D DTM		100.3	<0.001
	2D-3D DSM		48.6	0.372
	3D DTM-3D DSM		87.0	<0.001
() Vegetation	2D-3D DTM		111.6	<0.001
	2D-3D DSM		34.5	<0.001
	3D DTM-3D DSM		102.6	<0.001
() Cut side	2D-3D DTM		24.6	0.949
	2D-3D DSM		23.9	0.091
	3D DTM-3D DSM		3.9	<0.001
() Crest	2D-3D DTM		29.9	0.008
	2D-3D DSM		29.9	0.008
	3D DTM-3D DSM		0.0
() Clear	2D-3D DTM		122.9	<0.001
	2D-3D DSM		106.7	<0.001
	3D DTM-3D DSM		51.6	<0.001

correlation coefficient since the identical samples cannot be compared by the -test.