chaipanha, wuttikrai. “Development of Adjustment Factors affecting The Capacity of DRR Two-Lane Highways with Indirect Empirical Method”. Srinakharinwirot University Engineering Journal 15, no. 3 (December 28, 2020): 65–74. accessed December 6, 2025. https://ph02.tci-thaijo.org/index.php/sej/article/view/240921.