Modeling of Lateral Stability of Tractor-Semitrailer on Combined Alignments of Freeway

Table 7

Variance analysis of factors influencing the LTR on downgrades.

Source	Sum of squares	df	Mean square	value	Critical value
Corrected model	0.480	9	0.053	23.119
Intercept	4.197	1	4.197	1819.425
Radius	0.301	3	0.100	43.538
Grade	0.052	3	0.017	7.524
Speed	0.127	3	0.042	18.294
Error	0.014	6	0.002
Total	4.691	16
Correct total	0.494	15