Estimation of Annual Routine Maintenance Cost for Highway Tunnels

Table 3

Partial and part correlation analysis.

Dependent	Independent		Controlled variable	Partial	Part
TMC	Time	Age	AADT, ESAL, ∑ESAL, and PSLT	0.415	0.382
		∑ESAL	AADTT, Age, AADT, and ESAL	−0.192	−0.163
	Traffic	AADT	Age, ESAL, ∑ESAL, AADTT, and NT	0.410	0.348
		ESAL	PMLT,Age, AADT, ∑ESAL, and PMLT	0.076	0.062
		AADTT	Age, AADT, ESAL, ∑ESAL, NT, and PMLT	−0.043	−0.033
		PTT	PMLT, PST, and NT	−0.099	−0.095
	Tunnel parameters	NT	AADTT, AADT, PSLT, PLT, PMLT, PST, and NLF	−0.180	−0.134
		PSLT	Age, PMLT, and VNF	−0.059	−0.052
		PLT	NT, PLT, and NLF	0.115	0.109
		PMLT	ESAL, AADTT, PTT, NT, PSLT, PLT, PST, and VNF	−0.401	−0.330
		PST	AADTT, NT, PLT, PMLT, and NLF	0.266	0.250
		NVF	PSLT and PMLT	−0.274	−0.266
		NLF	NT, PLT, and PST	−0.094	−0.089