Analisis Gelombang Kejut Antrean Lalu Lintas pada Perlintasan Sebidang KA Kebon Pedes dengan Model Greenshields

Abstract

The railway level crossing on Kebon Pedes Road, Bogor City, is a crucial congestion bottleneck due to the high frequency of Commuter Line train operations, which triggers long vehicle queues during peak hours. This study aims to analyze macroscopic traffic flow characteristics and evaluate queue formation and dissipation phenomena using a combination of the Greenshields model and Shockwave Theory. Primary data were obtained through traffic volume counts, speed, and vehicle density surveys at the study location. The results of the Greenshields modeling demonstrate a linear relationship between speed (S) and density (D), expressed by the equation (S = 28.37 - 0.17D). From this relationship, the free-flow speed (Sff) was determined to be 28.37 km/h, the jam density (Dj) was 165.58 pcu/km, and the theoretical maximum road capacity (VM) was 1,174.51 pcu/h. Based on the shockwave analysis with a gate closure duration of 70 seconds, the backward forming shockwave (ωAB) was calculated at -6.30 km/h, and the backward recovery shockwave (ωCB) was -14.19 km/h. This phenomenon resulted in a maximum vehicle queue length (QM) reaching 220.25 meters from the stop line. The time required to fully dissipate the queue after the gate reopened was 55.89 seconds, with the total time for overall lane normalization reaching 101.52 seconds. These results indicate the need for adaptive traffic management or the construction of vertical infrastructure, such as underpasses or flyovers, to eliminate level crossing conflicts in the future.