Franklyn T. Amistad, Remedios R. Navarro and Rommel T. Tabunan 2007. An Analysis of the Level of Service of Unsignalized Intersections Along the Arterial Roads in the Heritage City of Vigan. The Vector: International Journal of Emerging Science, Technology and Management (IJESTM). 16, 1 (Dec. 2007). DOI:https://doi.org/10.69566/ijestm.v16i1.205.