Assessing the impact of traffic signal performance on crash frequency for signalized intersections along urban arterials: A random parameter modeling approach

2021 ◽  
Vol 149 ◽  
pp. 105868
Author(s):  
Rezwana Kabir ◽  
Stephen M. Remias ◽  
Steven M. Lavrenz ◽  
Jonathan Waddell
2021 ◽  
Vol 7 (2) ◽  
pp. 357-375
Author(s):  
Arlinda A. Rrecaj ◽  
Vlera Alimehaj ◽  
Marija Malenkovska ◽  
Cvetko Mitrovski

In this paper is going to be proposed a Cell Transmission Model (CTM), its analysis and evaluation with a case study, which addresses in a detailed way the aspect of merging and diverging operations on urban arterials. All those few CTM models that have been developed so far, to model intersections, have some limitations and drawbacks. First, unlike the simple composition road networks, such as highways, urban arterials must include some complex parts called merge sand diverges, due to the fact of vibrational values of reduced capacity, reduced saturation flow rate, etc. In order to simulate an urban network/arterial it is not possible to neglect the traffic signal indication on the respective time step. The objective of this paper is to highlight the difference between the results of the original CTM and our proposed CTM and to provide evidence that the later one is better than the old one.  The proposed and formulated model will be employed through an algorithm of CTM to model a segment- arterial road of Pristina (compound from signalized intersections). For the functionalization and testing of the proposed model is build the experimental setup that is compatible with the algorithm created on C# environment. Results show that the proposed model can describe light and congested traffic condition. In light traffic conditions, in great mass traffic flow is dictated by the traffic signal status, while in medium congestion is obtained a rapid increase of the density to each cell. Fluctuations of the density from the lowest to the highest values are obvious during the first three cycles to all cells of the artery in a congested traffic state. Doi: 10.28991/cej-2021-03091659 Full Text: PDF


Author(s):  
Qinaat Hussain ◽  
Wael K. M. Alhajyaseen ◽  
Kris Brijs ◽  
Ali Pirdavani ◽  
Tom Brijs

Unnecessary stopping at signalized intersections during yellow interval reduces traffic flow efficiency. The aim of this driving simulator study was to investigate the impact of an advanced countdown system on traffic flow efficiency during yellow interval at signalized intersections. The experiment was conducted using a driving simulator at Qatar Transportation and Traffic Safety Centre, Qatar University. Sixty-seven volunteers with a valid Qatari driving license participated in the study. Three signalized intersections for three scenarios were designed with the north bound of the Corniche road in the city of Doha as the real-life reference context. The control scenario was an untreated typical signalized intersection (default) with the signal order of green-yellow-red. The signal order was changed to green-flashing green-yellow-red in the condition with 3 seconds advanced flashing. In the third scenario, green LED lights were used as an advanced countdown system and was compared with a default traffic signal with order green-yellow-red and a flashing green traffic signal with order green-flashing green-yellow-red. The LED lights were installed over a 100 m stretch of the road surface with spacing of 5m. More specifically, these ground lights were integrated in the pavement marking strips indicating lane division and edge lines. Light units were flashed green, 3 seconds prior to the yellow interval, and then turned off one by one in sequential order towards the intersection at a predetermined speed. The system was aimed at providing advanced information and visualizing the inter-green period by means of a countdown system as a way to improve traffic flow efficiency. Study results showed that compared to the other two scenarios, drivers’ utilized the yellow interval in a better way in the scenario with green LED lights. Furthermore, results from binary logistic regression showed that probability of crossing the intersection was 30 and 2.6 times higher in the scenario with green LED lights compared to the flashing green and control scenarios, respectively. Regarding the red light running occurrences, there was no significant differences between the scenarios. Taking into account the results from this study, we recommend jurisdictions to further evaluate G-LED as a potentially effective treatment for increasing traffic flow efficiency during the inter-green period at signalized intersections.


2020 ◽  
Vol 66 (2) ◽  
pp. 27-31
Author(s):  
Anica Kocić ◽  
Nikola Čelar ◽  
Jelena Kajalić ◽  
Stamenka Stanković

Flashing green signal, as a part of the green traffic signal, indicates that the green signal is about to end. Drivers have more time to decide whether to stop or pass the intersection since they have prior information that the yellow signal will start. The application of flashing green at the end of the green signal is optional, hence, the question is how engineers could decide to use flashing green or not? The answer to the question should be based on researches on flashing green effects on traffic efficiency and safety at signalized intersections. The aim of this paper is to analyze the impact of flashing green on traffic efficiency by determining the value of effective green time. The research was conducted at two intersections in Belgrade, with and without a flashing green signal. Results indicate that effective green is shorter when flashing green is applied, due to the decreased utilization of the yellow signal.


Author(s):  
Patrick A. Singleton ◽  
Mark Taylor ◽  
Christopher Day ◽  
Subhadipto Poddar ◽  
Sirisha Kothuri ◽  
...  

The COVID-19 pandemic, the most significant public health crisis since the 1918–1919 influenza epidemic, is the first such event to occur since the development of modern transportation systems in the twentieth century. Many states across the U.S. imposed lockdowns in early spring 2020, which reduced demand for trips of various types and affected transportation systems. In urban areas, the shift resulted in a reduction in traffic volumes and an increase in bicycling and walking in certain land use contexts. This paper seeks to understand the changes occurring at signalized intersections as a result of the lockdown and the ongoing pandemic, as well as the actions taken in response to these impacts. The results of a survey of agency reactions to COVID-19 with respect to traffic signal operations and changes in pedestrian activity during the spring 2020 lockdown using two case study examples in Utah are presented. First, the effects of placing intersections on pedestrian recall (with signage) to stop pedestrians from pushing the pedestrian button are examined. Next, the changes in pedestrian activity at Utah signalized intersections between the first 6 months of both 2019 and 2020 are analyzed and the impact of land use characteristics is explored. Survey results reveal the importance of using technologies such as adaptive systems and automated traffic signal performance measures to drive decisions. While pedestrian pushbutton actuations decreased in response to the implementation of pedestrian recalls, many pedestrians continued to use the pushbutton. Pedestrian activity changes were also largely driven by surrounding land uses.


2020 ◽  
Author(s):  
Celia C. Lo ◽  
Young S. Kim ◽  
Thomas Allen ◽  
Andrea Allen ◽  
P. Allison Minugh ◽  
...  

2021 ◽  
Vol 38 (3) ◽  
pp. 415-428
Author(s):  
Florian Simon ◽  
Elodie Gautier-Veyret ◽  
Aurélie Truffot ◽  
Marylore Chenel ◽  
Léa Payen ◽  
...  
Keyword(s):  

Author(s):  
Mirco Pistelli ◽  
Valentina Natalucci ◽  
Lucia Bastianelli ◽  
Laura Scortichini ◽  
Veronica Agostinelli ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document