Determining Appropriate Lane-Changing Spacing for Off-Ramp Areas of Urban Expressways

Abstract

Congestion has become a significant issue in recent years and has greatly affected the efficiency of urban traffic operation. Random and disorderly lane-changing behavior greatly reduces traffic capacity and safety. This paper is mainly concerned with the relationship of lane-changing spacing intervals provided by off-ramp facilities and traffic flow conditions. Through field investigations in Beijing, several typical lane-changing behaviors at off-ramp areas are analyzed. By using field traffic data and actual road geometry parameters, VISSIM-based micro-behavior simulations at off-ramp areas are implemented to obtain traffic flow conditions with different lane-changing spacing intervals and other model parameters, such as traffic volume and ratio of off-ramp vehicles. Then, the numerical relationships between traffic flow state and model parameters can be shown. The results show that with increasing traffic volume and the ratio of off-ramp vehicles, the lane-changing spacing interval required by vehicles should be increased. For the same ratio of off-ramp vehicles, if the traffic volume increases by 100 pcu/h/lane (pcu is a unit to stand for a standard passenger car), the corresponding lane-changing spacing interval should be increased by a spacing of 50–100 m to avoid increasing congestion. Based on the results of this paper, smart lane management can be implemented by optimizing lane-changing spacing intervals and lane-changing behaviors to improve traffic capacity.

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• http://dx.doi.org/10.3390/su11072087 under the license https://creativecommons.org/licenses/by

• https://www.mdpi.com/2071-1050/11/7/2087/pdf under the license https://creativecommons.org/licenses/by/4.0

• https://www.mdpi.com/2071-1050/11/7/2087,

https://doaj.org/toc/2071-1050 under the license cc-by

• https://www.mdpi.com/2071-1050/11/7/2087,

https://www.mdpi.com/2071-1050/11/7/2087/pdf,

https://academic.microsoft.com/#/detail/2934461545

• https://www.mdpi.com/2071-1050/11/7/2087/pdf,

http://dx.doi.org/10.3390/su11072087

under the license https://creativecommons.org/licenses/by/4.0/