Development of a Relationship between Pavement Condition Index and International Roughness Index in Rural Road Network

Table 4

T-test results for predicted and observed pavement condition index.

IRI range		Paired differences					t	df	Sig. (2-tailed)
		Mean	Std. deviation	Std. error mean	95% confidence interval of the difference
					Lower	Upper
2.5–3.5	PCIO–PCIP	−0.244	1.15	0.081	−0.40	−0.08	−2.98	779	0.483
3.5–5	PCIO–PCIP	0.070	1.37	0.10	−0.13	0.27	0.67	163	0.499
5–7	PCIO–PCIP	−0.085	1.41	0.09	−0.26	0.09	−0.92	144	0.357

PCI_O, observed pavement condition index; PCI_P, predicted pavement condition index.