Simulation-Based Analysis of Moving Bottleneck Characteristics on Freeways

In highway operations, slow-moving vehicles often create moving bottlenecks that disrupt traffic flow and reduce capacity. This study employs the VISSIM simulation platform to analyze their effects under single-lane and two-lane scenarios. Key traffic indicators such as speed, density, and flow were collected under different bottleneck speeds and input volumes. Metrics including disturbance wave speed, following platoon length, and average vehicle speed were used to reveal the disturbance mechanisms. The Fourier transform further quantified speed oscillations and their spatial propagation. In the two-lane case, fundamental diagrams were constructed to compare capacity changes between the bottleneck lane and the adjacent lane, and among subsegments (bottleneck, following, and overtaking). Results show that moving bottlenecks cause significant speed disturbances and capacity reductions, with the magnitude determined by speed differentials and traffic density. These findings provide theoretical support for traffic flow modeling and the development of control strategies considering moving bottleneck effects.