Exploring the Impact of Differentiated Per-Lane Speed Limits on Traffic Safety of Freeways with Considering the Compliance Rate

Abstract

This is a subsequent study of a two-lane cellular automata (CA) traffic simulation model proposed by the authors. The current study focused on understanding the impacts of the configuration of the differentiated per-lane speed limit (DPLSL) and its compliance rate on traffic safety indexes, including lane-changing frequency, the coefficient of variation of speed, and incident rate of dangerous situations. The results indicate that freeway sections with DPLSL, especially the ones with complex DPLSL, have potentials to reduce the speed variation, lane changing frequencies, and chances of dangerous situations, resulting in higher traffic safety levels. Furthermore, under DPLSL configurations, the compliance rate of the lane of slow vehicles could positively affect the traffic safety levels. Specifically, as the decrease of the compliance rate, lane changing frequency slightly increases, the coefficient variation of speed especially of the outer lane increases, and the incident rate of the overtaking-on-the-right circumstances increases. In contrast to the simple DPLSL, freeway segments with the complex DPLSL configuration are more sensitive to the influence of the compliance rate.

Impact of Buses, Taxis, Passenger Cars, and Traffic Infrastructure on Average Travel Speed

“…e appropriate combination of factors to sustain acceptable traffic speed (i.e., below but close to the speed limit) while avoiding undesirable traffic speed (i.e., far below the speed limit) is a functional problem under intense investigation in the field (e.g., references [1][2][3][4][5][6][7][8]). In the present investigation, we want to identify the variables that most affect the average travel speed.…”

Impact of Cooperative Adaptive Cruise Control on a Multilane Highway under a Differentiated Per-Lane Speed Limit Policy

“…Moreover, two-way eight-lane highway is often accompanied with speed control or lane control measures, such as the differentiated per-lane speed limit (DPLSL) policy. DPLSL is a speed control measure frequently used in countries like China and Thailand out of concern for traffic safety and it is widely discussed in the literature (5)(6)(7). Under the DPLSL policy, the maximum speed limit and the minimum speed limit in each lane can be different, which influences drivers' lane changing behavior and makes the traffic flow on two-way eight-lane highways exhibit more complex features.…”