Table 1.

A summary of efforts in calibrating IRI prediction.

Literature	Region	R 2	MSE	Samples
AASHTO [33]	National (U.S.)	0.5118	0.0249	244
Schram, Abdelrahman [34]	National (U.S.)	0.621	0.0235	670
Tarefder, R.-R. [10]	New Mexico (U.S.)	0.326	0.12	85
Xiao and Wang [35]	Arkansas (U.S.)	0.476	0.063	193
Sufian [36]	Kansas (U.S.)	0.22	0.052	90
Souliman, M. [37]	Arizona (U.S.)	0.543	0.0355	178
Ceylan, K. [38]	Iowa (U.S.)	0.685	0.0196	65
Gulfam, Y. 13]	Ontario (Canada)	0.438	0.0775	90
Yuan, L. [39]	Ontario (Canada)	0.578	0.03	15