Signalized Intersection Capacity Adjustment Factors for Makkah, Saudi Arabia

Operation and performance of a signalized intersections relies on the roadway’s environmental features and users ’ behavioral characteristics which significantly differ among locations. Although the Highway Capacity Manual (HCM) provides general guide for designing traffic elements, its recommendations regarding particular values of design parameters may not be universally applicable. This paper analyses saturation flow rate and capacity adjustment factors for signalized intersection in Makkah, Saudi Arabia. Results of the research reveal that the capacity of signalized intersection in Makkah is 2500 passenger cars per hour of green time per lane which is significantly higher than the value prescribed in HCM. Capacity adjustments factors also vary from HCM recommendations. Moreover, research outputs might be utilized for formulating a Highway Capacity Manual for the country and estimated parameters may be useful in signal design and traffic system performance analysis in Saudi Arabia