Abstract:
Increasing traffic activity on urban road segments can affect the smoothness of traffic flow, particularly on road segments equipped with U-Turn facilities and intersection access conditions that influence vehicle movement patterns. One such road is Jalan Ibrahim Adjie in Bandung City, which has a fairly high traffic volume as well as substantial U-Turn activity. The high volume of vehicles performing U-Turn movements on this road segment has the potential to disrupt the main traffic flow, so a study on the effect of U-Turn activity on road performance is needed.This study aims to analyze traffic characteristics, analyze the effect of U-Turn activity on traffic flow, and calculate the performance of the Jalan Ibrahim Adjie segment using the 2023 Indonesian Road Capacity Guidelines (PKJI) method. The research method used is a quantitative approach through traffic surveys and field observations over seven days. The data collected include road geometry, traffic volume, U-Turn vehicle volume, side friction, and vehicle movement conditions. The analysis was conducted based on PKJI 2023 to obtain capacity values, degree of saturation, and Level Of Service of the road segment.The results show that the highest traffic volume occurred on Sunday at 07.00–08.00 WIB, amounting to 2,661.9 pcu/hour in the North–South direction and 2,621.6 pcu/hour in the South–North direction, while the volume of vehicles performing U-Turns reached 589.7 pcu/hour. Side friction was recorded at 474.8 and 469.0 weighted events/hour/200 m, classified as medium. Before U-Turn activity was taken into account, the degree of saturation was 0.80 in the North–South direction and 0.78 in the South–North direction, with a Level Of Service of LOS D. After U-Turn activity was taken into account, the degree of saturation increased to 0.97 and 0.96, changing the Level Of Service to LOS E. The closure of one arm of the Jalan Ibrahim Adjie–Jalan Gatot Subroto intersection also altered vehicle movement patterns, causing some vehicles to use the U-Turn facility as an alternative route, which added further disruption to the main traffic flow. Therefore, an integrated evaluation of intersection access arrangement and U-Turn facility management is needed to reduce disruption to traffic flow.
