scholarly journals Energy savings effectiveness of pretimed traffic control compared to actuated control at signalized intersections

1991 ◽  
Author(s):  
Shahaboddin Mohammad Elahi
Keyword(s):  
Traffic Control ◽  
Energy Savings ◽  
Signalized Intersections

State-Constrained Optimal Solutions for Safe Eco-Approach and Departure at Signalized Intersections

2020 ◽  
Author(s):  
Jihun Han ◽  
Dominik Karbowski ◽  
Aymeric Rousseau
Keyword(s):  
Analytical Solutions ◽  
Pure State ◽  
Energy Savings ◽  
Minimum Principle ◽  
Optimization Methods ◽  
Signalized Intersections ◽  
Constant Acceleration ◽  
Preceding Vehicle ◽  
Speed Change ◽  
Pass Through

Abstract This paper provides fundamentals of how to energy-efficiently pass through signalized intersections while avoiding any rear-end collisions with leading vehicles. In our previous works [1, 2], analytical solutions with and without second-order pure state constraints imposed by the preceding vehicle were presented; these showed significant energy saving potential for connected and automated vehicles (CAVs) compared to human-driven vehicles. However, these solutions were derived assuming that the desired distance headway policy does not include a speed change over a predictive horizon, and that the preceding vehicle has constant acceleration. We use the desired time headway policy that includes the speed change to define the first-order pure state constraint. We then derive analytical solutions using the direct adjoining method based on Pontryagin’s minimum principle. We also present a novel solver to compute energy-optimal and collision-free state trajectories by accounting for a piecewise constant acceleration of the preceding vehicle without using any numerical optimization methods that require initial guesses. For simple scenarios with one intersection, we analyze how the novel solver allows CAVs to smoothly pass through the signalized intersection and then reach a desired cruising speed. We also use a simulation framework based on high-fidelity powertrain models to validate its effectiveness based on energy savings when driving on real-world urban routes.

scholarly journals Comparison of Crash Severity Risk Factors at Signalized and Stop-Controlled Intersections in Urban and Rural Areas in Alabama

2018 ◽  
Vol 7 (5) ◽  
pp. 50
Author(s):  
Sumalatha Kesavareddy ◽  
Kirolos Haleem ◽  
Mehrnaz Doustmohammadi ◽  
Michael Anderson
Keyword(s):  
Traffic Control ◽  
Rural Areas ◽  
Signalized Intersections ◽  
Crash Severity ◽  
Factors Affecting ◽  
Side Impacts ◽  
Binary Logit ◽  
Urban And Rural Areas ◽  
New Variables ◽  
Significant Factors

Understanding the factors that affect crash severity at intersections is essential to develop strategies to alleviate safety deficiencies. This paper identifies and compares the significant factors affecting crash severity at signalized and stop-controlled intersections in urban and rural areas in Alabama using recent five-year crashes. A random forest model was used to rank variable significance and a binary logit model was applied to identify the significant factors at both intersection types in urban and rural areas. Four separate models (urban signalized, urban stop-controlled, rural signalized, and rural stop-controlled) were developed. New variables that were not previously explored were used in this study, such as the roadway type (one-way vs. two-way) and traffic control functioning (yes or no). It was found that one-way roadways were associated with a reduction in crash severity at urban signalized intersections. In all four models, rear-end crashes showed lesser severity than side impacts. Head-on crashes, higher speed limits, and curved sections showed higher severity in urban signalized and stop-controlled intersections. In rural stop-controlled intersections, right-turning maneuvers had a severity reduction. Female drivers showed 15% and 45% higher severity likelihood (compared to males) at urban and rural signalized intersections, respectively. Strategies to alleviate crash severity are proposed.

scholarly journals An Adaptive Model for Calculating the Correlation Degree of Multiple Adjacent Signalized Intersections

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Linhong Wang ◽  
Yiming Bie
Keyword(s):  
Traffic Control ◽  
Real Life ◽  
Signalized Intersections ◽  
Relative Performance ◽  
Control Mode ◽  
Correlation Model ◽  
Contributing Factors ◽  
The Road ◽  
Correlation Degree ◽  
Multiple Intersections

As an important component of the urban adaptive traffic control system, subarea partition algorithm divides the road network into some small subareas and then determines the optimal signal control mode for each signalized intersection. Correlation model is the core of subarea partition algorithm because it can quantify the correlation degree of adjacent signalized intersections and decides whether these intersections can be grouped into one subarea. In most cases, there are more than two intersections in one subarea. However, current researches only focus on the correlation model for two adjacent intersections. The objective of this study is to develop a model which can calculate the correlation degree of multiple intersections adaptively. The cycle lengths, link lengths, number of intersections, and path flow between upstream and downstream coordinated phases were selected as the contributing factors of the correlation model. Their jointly impacts on the performance of the coordinated control mode relative to the isolated control mode were further studied using numerical experiments. The paper then proposed a correlation index (CI) as an alternative to relative performance. The relationship between CI and the four contributing factors was established in order to predict the correlation, which determined whether adjacent intersections could be partitioned into one subarea. A value of 0 was set as the threshold of CI. If CI was larger than 0, multiple intersections could be partitioned into one subarea; otherwise, they should be separated. Finally, case studies were conducted in a real-life signalized network to evaluate the performance of the model. The results show that the CI simulates the relative performance well and could be a reliable index for subarea partition.

scholarly journals Optimization of cycle time on signalized intersections of H.E.A Mokodompit Street – M.T Haryono – H.A. Nasution Kendari city based on traffic flow volume

2021 ◽  
Vol 1 (1) ◽  
pp. 039-048
Author(s):  
Ridwan Syah Nuhun ◽  
Usman Rianse ◽  
Marsuki Iswandi ◽  
Adris Ade Putra ◽  
Abdul Kadir ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Cycle Time ◽  
Traffic Control ◽  
Service Level ◽  
Light Signal ◽  
Signalized Intersections ◽  
Degree Of Saturation ◽  
Traffic Light ◽  
The North ◽  
Control Light

Intersection of H.E.A. Mokodompit Street – M.T. Haryono – H.A. Nasution is one of the signalized intersections in Kendari City which has congestion problems, vehicle accumulation and vehicle queues at each arm of the intersection at rush hour due to the large volume of traffic flow and not optimal cycle timing from the traffic light signal. The purpose of this study is to optimize the cycle time of traffic control light signals based on traffic volume and to analyze the performance of these intersections. The results of the analysis based on the volume of traffic flow obtained the optimal cycle time of 72 seconds with the division of green time in each approach by 18 seconds for the north approach, 14 seconds for the eastern approach and 28 seconds for the south approach. The degree of saturation at each intersection arm is 0.82 which is at the service level D.

Operational Impacts of Protected-Permitted Right-Turn Phasing and Pavement Markings on Bicyclist Performance during Conflicts with Right-Turning Vehicles

2019 ◽  
Vol 2673 (4) ◽  
pp. 789-799
Author(s):  
Masoud Ghodrat Abadi ◽  
David S. Hurwitz
Keyword(s):  
Traffic Control ◽  
Safety Concern ◽  
Lateral Position ◽  
Signalized Intersections ◽  
Pavement Markings ◽  
Conflict Area ◽  
Flashing Yellow Arrow ◽  
Mixed Factorial Design ◽  
Operational Impacts ◽  
Yellow Arrow

Conflict between bicycles and right-turning vehicles on the approach to signalized intersections is a critical safety concern. To understand the operational implications of protected-permitted right-turn signal indications in conjunction with pavement markings on bicyclist performance, a full-scale bicycling simulator experiment was performed. Velocity and lateral position of bicyclists were evaluated during conflicts between bicycles and right-turning vehicles. A mixed factorial design was considered. Two within-subject factors were analyzed: the signal indication for right-turning vehicles with five levels (circular red, circular green, solid red arrow, solid green arrow, and flashing yellow arrow), and the pavement markings in the conflict area with two levels (white lane markings with no supplemental pavement color and white lane markings with solid green pavement applied in the conflict area). Additionally, the influence of gender as a between-subject variable was considered. Forty-eight participants (24 female) completed the experiment. Signal indications and pavement markings had statistically significant effects on bicyclist velocity and lateral position, but these effects varied at different factor levels. Additionally, during the conflicts, male participants were found to have higher velocity than female participants. This difference was not influenced by engineering treatments. The results provide guidance to transportation professionals about how traffic control devices could be applied to conflict areas on the approach to signalized intersections.

Queue-Based Guidance for Signalization Consideration at Two and Three-Legged Intersections

2019 ◽  
Vol 2673 (10) ◽  
pp. 416-426
Author(s):  
Shannon Warchol ◽  
Nagui Rouphail ◽  
Chris Vaughan ◽  
Brendan Kearns
Keyword(s):  
North Carolina ◽  
Traffic Control ◽  
Signalized Intersections ◽  
Data Driven ◽  
Left Turn ◽  
Minor Road ◽  
Adjustment Factors ◽  
Queue Lengths ◽  
Control Devices ◽  
A Minor

This research collected and analyzed gap acceptance in North Carolina to develop a data-driven method for determining the need for considering additional signalization analysis at intersections with fewer than four legs. This method can be used for movements that merge with or cross two lanes of oncoming traffic. It is intended to provide guidance and support to traffic engineers in their decision-making process. Charts are provided to determine the expected 95th percentile queue lengths for left-turn, right-turn, and U-turn movements crossing or merging with two lanes of conflicting traffic. This situation is typically present along four-lane roadways where a one-way primary movement opposes either a minor road right-turn movement or a left-turn movement, or in the case of a median U-turn opening. Adjustment factors to the conflicting flowrate were developed to account for the presence of upstream signalized intersections. This method less frequently recommends further signal consideration when compared with the Manual on Uniform Traffic Control Devices peak hour warrant, but is similar to the delay-based level of service D/E threshold for two-way stop-controlled intersections in HCM6 Chapter 19.

scholarly journals Passenger number dependent traffic control in signalized intersections

2013 ◽  
Vol 57 (2) ◽  
pp. 201 ◽  
Author(s):  
János Polgár ◽  
Tamás Tettamanti ◽  
István Varga
Keyword(s):  
Traffic Control ◽  
Signalized Intersections

Determination of Pedestrian Push-Button Activation Duration at Typical Signalized Intersections

2005 ◽  
Vol 1939 (1) ◽  
pp. 63-68
Author(s):  
David A. Noyce ◽  
Billie Louise Bentzen
Keyword(s):  
Traffic Control ◽  
Time Distribution ◽  
Primary Objective ◽  
Signalized Intersections ◽  
Button Press ◽  
Vehicular Traffic ◽  
Push Button ◽  
Control Information ◽  
Pedestrian Signals

Recent advances in pedestrian push-button design, led by the development of accessible pedestrian signals (APSs), have created a new method of communicating traffic control information to pedestrians. Some APS devices have beaconing features or verbal (speech) message capabilities obtained by pressing and holding the pedestrian push button for approximately 3 s. Other features, such as the extension of the walk interval, may also be activated with an extended press of the push button. Recent research has suggested that 3 s may be excessive because it is hard for some users to hold the push button for this long. Additionally, most pedestrians may not hold the push button for this length of time. The problem lies in determining how long the APS push button should be pressed for a push-button information message or special accessibility features to be obtained. The primary objective of the research described in this paper was to develop a time distribution of typical pedestrian push-button activation durations. Data were obtained by attaching a voltage recorder to the pedestrian push-button circuit inside traffic signal controllers at eight locations in three cities in Wisconsin and Massachusetts. This device recorded the amount of time, to the nearest 1/100 of a second, that each pedestrian push button was pressed. A total of 1,439 push-button presses were recorded. The average push-button press duration was 0.2 s. More than 95% of all push-button presses recorded were less than 1.0 s. Only four push-button presses exceeded 3.0 s. The results show that the duration of an extended push-button press needed to obtain additional crossing information can be reduced to approximately 1 s without a significant number of false calls. A 1-s press will minimize the effort required for pedestrians to actuate special accessible features, while it will minimize unnecessary noise and vehicular traffic disruption.

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