Pengaruh U-Turn pada lengan barat terhadap biaya kerugian bahan bakar minyak akibat kemacetan di simpang empat UPN Sleman Yogyakarta

The four-leg signalized APILL UPN Sleman intersection experiences high traffic demand during peak hours. The existence of a U-turn facility on the west approach generates additional traffic conflicts, which lead to a decrease in intersection performance, an increase in vehicle delays, and higher fuel consumption losses. This study aims to evaluate the existing operational performance of the intersection, analyze the impact of the U-turn movement on the west approach, and estimate fuel consumption losses resulting from traffic congestion. The evaluation of intersection performance was conducted using the Indonesian Highway Capacity Guidelines (PKJI) 2023 and microscopic traffic simulation with PTV Vissim. Meanwhile, fuel consumption losses were estimated using the LAPI-ITB method and the Lamsal (ATIS-India) method. The analysis results indicate that under existing conditions, the intersection operates with an average delay of 293.66 s/veh and a degree of saturation of 1.24, which corresponds to Level of Service (LOS) F. In addition, the U-turn movement on the west approach shows a degree of saturation of 1.10 and an average delay of 71.29 s/veh. The estimated fuel consumption losses under existing conditions reach IDR 4.01 million based on the LAPI-ITB method and IDR 3.86 million based on the Lamsal method. Although the overall performance of the intersection remains at Level of Service F, the implementation of improvement alternatives is able to reduce vehicle delays and fuel consumption losses.