Lateral Drift Behavior Analysis in Mixed Bicycle Traffic: A Cellular Automaton Model Approach

Xue Feng,Xi-Fu Wang,Dong-Fan Xie

doi:10.1155/2016/7962171

Abstract

Bicycle movements are always associated with lateral drifts. However, the impacts of lateral drift behavior, as well as variable lateral clearance maintaining behavior due to the variation of drift intensity, on mixed bicycle flow are not clear. This paper establishes a new cellular automata model to study typical characteristics of mixed bicycle traffic induced by lateral drift and its accompanying behavior. Based on derived positive correlation between passing speed and drift speed through survey, the occurrence probability of lateral drift and the degree of maintained lateral clearance are both introduced in accordance with the variance of passing speed. Then, in whole density region, firm conformity between simulation results and actual survey data is reached, which has seldom been achieved in previous studies. It is further verified that speed distortions in intermediate and high density region induced by assumption of constant lateral clearance requirements can be revised by introducing its variability characteristics. In addition, two contrastive impacts of lateral drift behavior are observed. That is, it causes speed fluctuation in low density while alleviating the speed fluctuation in relatively high density. These results are expected to be helpful to improve the simulation performance of mixed bicycle flow as well as depict more realistic vehicle-bicycle conflicts and so on.

Highlights

IntroductionIn urban areas of China, conventional bicycles (abbreviation c-bicycles) as well as electronic bicycles (abbreviation ebicycles) are still prevalent for most short-distance trips in recent years
In urban areas of China, conventional bicycles as well as electronic bicycles are still prevalent for most short-distance trips in recent years
As one of the most important microscopic models, cellular automata (CA) model has been widely used in elucidating traffic flows for its conceptual simplicity and fast performance

Summary

Introduction

In urban areas of China, conventional bicycles (abbreviation c-bicycles) as well as electronic bicycles (abbreviation ebicycles) are still prevalent for most short-distance trips in recent years. A systematic study of the characteristics and effects of variable lateral clearance maintaining behavior will be a meaningful attempt to elucidate mixed bicycle flow. A review of relevant research shows that, so far, the impacts of lateral drifts are seldom explored; besides, related research into the variability of lateral clearance maintaining behavior is lacking These limitations motivate us to develop a new CA model incorporating the lateral drift behavior and its consequent variable lateral clearance maintaining behavior to investigate the mixed bicycle flow. Based on the enhanced resolution of the finer cell system and the model calibration obtained from the field investigations in Beijing, China, many important characteristics of mixed bicycle traffic are captured and elucidated.

Survey Method of Passing Speed-Drift Speed Characteristics

Simulations and Analyses

Findings

Conclusion