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Dynamic Road Management in the Era of CAV
Published in Hussein T. Mouftah, Melike Erol-Kantarci, Sameh Sorour, Connected and Autonomous Vehicles in Smart Cities, 2020
Mohamed Younis, Sookyoung Lee, Wassila Lalouani, Dayuan Tan, Sanket Gupte
Some DLR approaches have been specific to particular road layouts and cannot be generalized to other layouts [144–147]. The focus of Li et al. [144] is on a signalized intersection with six lanes and two additional reversible center lanes. Only four scenarios are considered for typical urban morning and evening peak-hours. In Refs. [145,146], a signalized diamond interchange is considered, where the proposed DLR approaches strive to handle the concern of space limitation for different turns in order to reduce oversaturation at the interchange. Krause et al. [145] opt to show the effectiveness of dynamic back-to-back reversible left-turn in collaboration with a TLS controller, while Zhao et al. [146] strive to maximize the reserved capacity of the internal lanes at the intersection considering a fixed set of TLS phases. On the other hand, the focus of [147] is on the applicability of DLR to existing lanes for dynamic left-turn traffic, as articulated in Figure 5.6. With the help of an additional traffic light (presignal) installed at the median opening, exit lanes for left-turn control problem were formulated as a mixed-integer nonlinear program, in which the geometric layout, main signal timing, and presignal timing were integrated and transformed into a series of mixed-integer linear programs. The results have shown significant growth in the intersection capacity and reduction of traffic delay, especially under high left-turn demand.
Road Traffic Control
Published in Dušan Teodorović, The Routledge Handbook of Transportation, 2015
Diamond intersection operation constitutes a special case from the perspective of traffic signal control. This type of facility usually requires control with special phasing sequences. Several authors represented and modeled control for signalized diamond interchanges. Koonce, Urbanik II, and Bullock used PASSER III along with HILS for optimizing and modeling diamond interchange operations.45 Later papers also presented special signal control strategies for diamond interchange,46,47 that used overlap phases with the timing that is guided by travel time between two signals. In the diamond intersection, control progression is usually provided for major movements, and one controller can control two intersections.
Traffic and Transportation Engineering
Published in P.K. Jayasree, K Balan, V Rani, Practical Civil Engineering, 2021
P.K. Jayasree, K Balan, V Rani
Interchange is where the traffic between at least two pathways at various levels in the grade-isolated intersections. Diverse sorts are as follows: Diamond interchange: Most prominent type of four-leg interchange found in the urban areas where major and minor streets cross.It can be structured regardless of whether the major road is moderately restricted.Clover leaf interchange: A four-leg interchange, utilized when two expressways of high volume and speed cross one another.Advantage: it gives finish detachment of traffic. Likewise fast speed at crossing points can be accomplished.Disadvantage: vast region of land is needed.Trumpet interchange It is a three-leg interchange. On the off chance that one of the legs of the interchange meets a roadway at some edge however does not cross it; at that point the interchange is known trumpet interchange.
Identification of contributing factors for interchange crashes based on a quasi-induced exposure method
Published in Journal of Transportation Safety & Security, 2022
Xin Gu, Mohamed Abdel-Aty, Jaeyoung Lee, Qiaojun Xiang, Yongfeng Ma
From the findings in this study, more attention should be paid in the perspective of infrastructure enhancement, driver education and licensing for improving traffic safety at interchange facilities. Also, the results from this study can provide guidance to transportation planners and enable them to take traffic safety into account in the long-term planning. For instance, diamond interchange has lower crash risk than other interchanges. Regarding the road factors, paving shoulders, installing more visible signs and markings would be effective measures to increase drivers’ awareness of the road environment and make their driving maneuvers safer. Moreover, it is suggested to provide wider shoulder nearby interchanges. Concerning the higher risk driver populations, more effective education programs and a stricter licensing system could be considered to reduce interchange crash risk resulting from human errors, which were also suggested by Curry, Pfeiffer, Durbin, and Elliott (2015) and Curry, Metzger, Williams, and Tefft, (2017). There might be two reasons for the increased crash risk among younger drivers. One would be that younger drivers usually lack of risk perception and adequate knowledge of traffic rules. Another would be that some younger drivers pursuing excitements and taking risks while driving. For younger drivers, programs to educate the risk factors in driving behavior and road environment related to interchanges would be effective. For example, when driving on the acceleration lane at interchange merging areas, drivers need to accelerate to an adequate speed, which has no large difference with speed of vehicles on the freeway lane, in turn making a merging maneuver.