Estimation of Annual Routine Maintenance Cost for Highway Tunnels

Table 6

Fixed-effect regression model.

Variables	Beta	β	t
lnAge	0.685	1.222	3.60	0.001
lnAADT	−1.032	−0.604	−3.33	0.002
PTT	0.469	2.881	2.72	0.010
PSLT	0.128	1.972	1.14	0.259
PLT	0.210	1.302	1.35	0.184
PMLT	−0.049	−0.564	−0.22	0.826
lnNVF	−0.681	−1.334	−2.81	0.008
Constant	1	8.788	3.39	0.002
Guanzhong	0.896	10.944	2.53	0.016
Shannan	0.898	11.012	2.49	0.017
R^2		0.4771
F		5.47
		0.0001