Stay in your lane: Density fluctuations in multi-lane traffic

TL;DR

This paper introduces a stochastic model to analyze how spontaneous lane changing impacts traffic flow, revealing that random lane switches can significantly reduce overall traffic throughput, especially in multi-lane scenarios.

Contribution

The study presents a novel stochastic model of spontaneous lane changing and analyzes its effects on traffic flow through both analytical and simulation methods.

Findings

Lane changing causes a measurable slowdown in traffic flow.

Flow reduction is more pronounced in the middle lane of three-lane traffic.

Analytical and simulation results agree on the impact of lane switching.

Abstract

When a new vehicle joins a lane, those behind may have to temporarily slow to accommodate them. Changing lane can be forced due to lane drops or junctions, but may also take place spontaneously at discretion of drivers, and recent studies have found that traffic jams and traffic oscillations can form even without such bottlenecks. Understanding how lane changing behaviour affects traffic flow is important for learning how to design roads and control traffic more effectively. Here, we present a stochastic model of spontaneous lane changing which exhibits a reduction in the overall flow of traffic. By examining the average flow rate both analytically and through simulations we find a definitive slow down of vehicles due to random switching between lanes. By extending the model to three lane traffic we find a larger impact on the flow of the middle lane compared to the side lanes.