Saturation Flow Versus Green Time at Two‐stage Signal Controlled Intersections

Abstract

Abstract.Intersections are the key components of road networks considerably aff ecting capacity. As fl ow levels and experience have increased over the years, methods and means have been developed to cope with growing demand for traffi c at road junctions. Among various traffi c control devices and techniques developed to cope with confl icting movements, traffi c signals create artifi cial gaps to accommodate the impeded traffi c streams. Th e majority of parameters that govern signalised intersection control and operations such as a degree of saturation, delays, queue lengths, the level of service etc. are very sensitive to saturation fl ow. Th erefore, it is essential to reliably evaluate saturation fl ow for correctly setting traffi c signals to avoid unnecessary delays and confl icts. Generally, almost all guidelines support the constancy of saturation fl ow irrespective of green time duration. Th is paper presents the results of fi eld studies carried out to enable the performance of signalised intersections to be compared at diff erent green time durations. It was found that saturation fl ow decreased slightly with growing green time. Reduction corresponded to between 2 and 5 pcus/gh per second of green time. However, the analyses of the discharge rate during the successive time intervals of 6-seconds showed a substantial reduction of 10% to 13% in saturation fl ow levels aft er 36 seconds of green time compared to those relating to 6-36 seconds range. No reduction in saturation fl ow levels was detected at the sites where only green periods of 44 seconds or less were implemented.

Queue discharge patterns at signalized intersections with green signal countdown device and long cycle length

“…Boumediene et al . found that saturation flow rate decreased slightly with growing green time. HCM 2000 also supported that the saturation headway might rise when the length of green time exceeds 50 seconds .…”

A Study of the Deflections of Metal Road Guardrail Post

“…Traffic safety problems, such as the interaction between a motor vehicle and road guardrails, motor vehicle dynamics and guardrails of various types were investigated in different time periods by Antov et al (2009), Beljatynskij et al (2009), Boumediene et al (2009), Çalışkanelli et al (2009), Cansiz and Atahan (2006), Coon and Reid (2005), Dragčević et al (2009), Elvik et al (1997), Ibitoye et al (2006), Junevičius and Bogdevičius (2009), Kapski et al (2008), Kinderytė-Poškienė and Sokolovskij (2008), Lazda and Smirnovs (2009), Macek and Měšťanová (2009), Nagurnas et al (2008), Pelenytė-Vyšniauskienė and Jurkauskas (2007), Prentkovskis et al (2007;2009), Sokolovskij et al (2007), Šliupas (2009), Tautkus and Bazaras (2007), Vansauskas and Bogdevičius (2009), Viba et al (2009), Vorobjovas and Žilionienė (2008), etc.…”

Research of Congestions in Urban Transport Network Using Cellular Automation Model / Spūsčių Miesto Transporto Tinkle Tyrimas, Taikant Ląstelinio Automato Modelį / Исследование Перегрузки Городской Транспортной Сети С Применением Модели Клеточного Автомат

“…Using the cellular automaton (CA) model it is possible to describe the complex, global and coherent systems and nonlinear phenomena using simple rules. CA models are discrete, which, by their nature, are strictly determined and obeying various laws, but their behaviour can be so complex that it is sometimes difficult to distinguish it from stochastic processes, and the same process may seem chaotic and unpredictable (Boumediene et al 2009;Gowri, Sivanandan 2008;Lárraga et al 2005).…”