Abstract
THE OPERATIONAL PERFORMANCE OF AL-BAHA’S TWO-LANE MOUNTAINOUS ROADS: A CASE STUDY
Jamil Abdulrabb Naji*
ABSTRACT
The King Fahd two-lane mountainous road serves as a crucial connection between Al-Baha, a key tourist destination, and the coastal towns of Tehama. This study evaluates the road's operational performance by examining its Level of Service (LOS) and capacity, utilizing the procedures from the Highway Capacity Manual (HCM-6th edition, 2016). Data collected during the winter of 2018 was analyzed to determine the road’s Average Travel Speed (ATS), Percent TimeSpent Following (PTSF), and overall capacity. The analysis revealed that the road operates at a constrained LOS D, with a high PTSF of 77.6%, indicating limited opportunities for overtaking, despite an ATS of 46.2 mph (74.3 kph). The capacity was calculated at 1632 passenger car equivalents per hour, largely influenced by the challenging mountainous terrain and the prevalence of heavy vehicles. These findings underscore the need for road improvements to alleviate congestion, reduce driver frustration, and enhance safety, particularly during peak traffic and tourist seasons.
[Full Text Article] [Download Certificate]