Comparative Effectiveness of Roundabouts and Traffic Signals as Alternative Treatments for Unsignalized Intersections under Projected Traffic Growth (A Case Study of the Wadung Asri–Brebek–Gedong Masjid Intersection, Sidoarjo Regency.)

Abstract

Unsignalized intersections are vulnerable to performance degradation as traffic volume increases, particularly at the Wadung Asri–Brebek–Gedong Masjid Intersection in Sidoarjo Regency. This study aims to analyze the intersection performance based on the 2023 Indonesian Highway Capacity Guidelines (PKJI 2023) and compare the effectiveness of a roundabout and a signalized intersection (APILL) as alternative treatments under projected traffic growth. The research method involved manual traffic surveys conducted over four days during peak hours, including traffic volume and intersection geometric data. The results show that the existing condition has a degree of saturation (DS) of 0.88 with an average delay of 15.16 s/SMP. Based on the traffic projection for the design year of 2030, the DS increases to 1.11, with an average delay of 26.08 s/SMP, indicating that the intersection does not meet the PKJI 2023 standard (DS < 0.85). The first treatment involved geometric widening of each intersection approach and designing a roundabout, resulting in a DS of 1.07 and an average delay of 52.00 s/SMP. The second treatment involved geometric widening of each intersection approach and the design of a four-phase signalized intersection, resulting in a DS of 0.79 and an average delay of 51.80 s/SMP. Therefore, geometric widening combined with a four-phase signalized intersection is recommended as the preferred treatment alternative because it achieves a DS that meets the PKJI 2023 standard, with a relatively comparable delay to the roundabout alternative. Contribution to Sustainable Development Goals (SDGs):SDG 9   : Sustainable Transportation InfrastructureSDG 11 : Sustainable Urban MobilitySDG 13 : Climate Action