scholarly journals A new approach to estimate pedestrian delay at signalized intersections

Transport ◽  
2016 ◽  
Vol 33 (1) ◽  
pp. 249-259 ◽  
Author(s):  
Sankaran Marisamynathan ◽  
Perumal Vedagiri
Keyword(s):  
Time Delay ◽  
Waiting Time ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Model Parameters ◽  
Clear Understanding ◽  
Delay Model ◽  
Crossing Time ◽  
Pedestrian Crossing ◽  
Compliance Behaviour

Enhancing pedestrian safety and improving the design standards of pedestrian facilities at signalized intersection requires a clear understanding of pedestrian delay model and pedestrian crossing behaviours under mixed traffic condition. The existing delay models do not consider the behavioural constrains of pedestrians. This research has been undertaken with the aim of developing a suitable pedestrian delay model for signalized intersection crosswalks, based on considering actual pedestrian crossing behaviours. The required model parameters were extracted from the video-graphic survey conducted for the selected four signalized intersections in Mumbai (India). Crossing behaviours of pedestrians were examined through field data in terms of pedestrian arrival pattern, crossing speed, compliance behaviour and pedestrian–vehicular interactions. Based on pedestrian crossing behaviour analysis results, two new pedestrian delay estimation models were developed and the models were validated by comparing with field and existing model values. The performance level of the proposed models is showing more precise and reliable solutions. The first pedestrian delay model is developed on the basis of compliance behaviour, has two components, such as waiting time delay and crossing time delay. This model can be used to evaluate pedestrian Level Of Service (LOS) and signal timing optimization. The second developed pedestrian delay model is based on noncompliance behaviour, has three components, such as waiting time delay, crossing time delay, and pedestrian–vehicular interaction delay. This model can also be used to evaluate the quality of pedestrian flow, estimating accurate pedestrian delay and LOS for local conditions, which is representative of the prevailing pedestrian condition.

scholarly journals Identification of LTI Time-Delay Systems with Missing Output Data Using GEM Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Xianqiang Yang ◽  
Hamid Reza Karimi
Keyword(s):  
Time Delay ◽  
Linear Time ◽  
Irregular Sampling ◽  
Delay Systems ◽  
Model Parameters ◽  
Delay Model ◽  
Sensor Failure ◽  
Linear Time Invariant ◽  
Failure Data ◽  
Time Invariant

This paper considers the parameter estimation for linear time-invariant (LTI) systems in an input-output setting with output error (OE) time-delay model structure. The problem of missing data is commonly experienced in industry due to irregular sampling, sensor failure, data deletion in data preprocessing, network transmission fault, and so forth; to deal with the identification of LTI systems with time-delay in incomplete-data problem, the generalized expectation-maximization (GEM) algorithm is adopted to estimate the model parameters and the time-delay simultaneously. Numerical examples are provided to demonstrate the effectiveness of the proposed method.

Scramble and Crosswalk Signal Timing

1998 ◽  
Vol 1636 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Mark R. Virkler
Keyword(s):  
Field Study ◽  
High Volume ◽  
Signalized Intersections ◽  
Signal Timing ◽  
Pedestrian Flow ◽  
Crossing Time ◽  
Time Required ◽  
Pedestrian Crossing

A variety of methods have been developed for determining appropriate pedestrian crossing times at signalized intersections. Although many of these methods have useful applications, all have significant shortcomings when estimating the crossing time required under high-volume conditions and with two-way flow within a crosswalk. Existing methods are described. A field study conducted to address these shortcomings is then described. The results of the study are used to develop relationships to describe pedestrian flow at signalized crossings. Recommendations are then made to improve the signal timing parameters used for higher-volume pedestrian flows.

scholarly journals A NEW DELAY PARAMETER DEPENDENT ON VARIABLE ANALYSIS PERIODS AT SIGNALIZED INTERSECTIONS. PART 1: MODEL DEVELOPMENT

Transport ◽  
2008 ◽  
Vol 23 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Ali Payidar Akgüngör
Keyword(s):  
Model Development ◽  
Traffic Signals ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Delay Model ◽  
Delay Models ◽  
Dependent Model ◽  
New Formulation ◽  
Parameter Dependent

Delay is an important factor in the optimization of traffic signals and the determination of the level of service of a signalized intersection. This paper proposes a methodology and a new formulation to identify the delay parameter in signalized intersection delay models. In this study, the delay parameter is modeled as a function of analysis period instead of a fixed value used by the existing delay models. Therefore, the proposed delay model including new delay parameter can produce more reasonable delay estimations at signalized intersections for variable time periods. A comparative study of the proposed time‐dependent model against the existing four different models was performed to present the improvements in this model.

scholarly journals Novel Time-Delay Side-Collision Warning Model at Non-Signalized Intersections Based on Vehicle-to-Infrastructure Communication

2021 ◽  
Vol 18 (4) ◽  
pp. 1520
Author(s):  
Nengchao Lyu ◽  
Jiaqiang Wen ◽  
Chaozhong Wu
Keyword(s):  
Time Delay ◽  
Response Time ◽  
Signalized Intersections ◽  
Traditional Model ◽  
Delay Model ◽  
Warning Systems ◽  
Collision Warning ◽  
Vehicle To Infrastructure ◽  
Side Collision ◽  
Warning Model

In complex traffic environments, collision warning systems that rely only on in-vehicle sensors are limited in accuracy and range. Vehicle-to-infrastructure (V2I) communication systems, however, offer more robust information exchange, and thus, warnings. In this study, V2I was used to analyze side-collision warning models at non-signalized intersections: A novel time-delay side-collision warning model was developed according to the motion compensation principle. This novel time-delay model was compared with and verified against a traditional side-collision warning model. Using a V2I-oriented simulated driving platform, three vehicle-vehicle collision scenarios were designed at non-signalized intersections. Twenty participants were recruited to conduct simulated driving experiments to test and verify the performance of each collision warning model. The results showed that compared with no warning system, both side-collision warning models reduced the proportion of vehicle collisions. In terms of efficacy, the traditional model generated an effective warning in 84.2% of cases, while the novel time-delay model generated an effective warning in 90.2%. In terms of response time and conflict time difference, the traditional model gave a longer response time of 0.91 s (that of the time-delay model is 0.78 s), but the time-delay model reduced the driving risk with a larger conflict time difference. Based on an analysis of driver gaze change post-warning, the statistical results showed that the proportion of effective gaze changes reached 84.3%. Based on subjective evaluations, drivers reported a higher degree of acceptance of the time-delay model. Therefore, the time-delay side-collision warning model for non-signalized intersections proposed herein can improve the applicability and efficacy of warning systems in such complex traffic environments and provide reference for safety applications in V2I systems.

A Direct Estimation Method of Second Order Plus Time Delay Model Parameters for PID Controller Autotuning.

1999 ◽  
Vol 32 (3) ◽  
pp. 288-294 ◽  
Author(s):  
Kyung Joo Chung ◽  
Hee Jin Kwak ◽  
Su Whan Sung ◽  
In-Beum Lee ◽  
Jin Yong Park
Keyword(s):  
Time Delay ◽  
Pid Controller ◽  
Estimation Method ◽  
Second Order ◽  
Model Parameters ◽  
Delay Model ◽  
Direct Estimation

Parameter identification of nonlinear multirate time-delay system with uncertain output delays

2017 ◽  
Vol 40 (12) ◽  
pp. 3498-3506 ◽  
Author(s):  
Xianqiang Yang ◽  
Weili Xiong ◽  
Zeyuan Wang ◽  
Xin Liu
Keyword(s):  
Time Delay ◽  
Time Delays ◽  
Finite Impulse Response ◽  
Delay System ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Model Parameters ◽  
Delay Model ◽  
Process Data ◽  
Time Delay System

The joint parameter and time-delay estimation problems for a class of nonlinear multirate time-delay system with uncertain output delays are addressed in this paper. The practical process typically has time-delay properties and the process data are often multirate, sampled with output data inevitably corrupted by uncertain delays. The linear parameter varying (LPV) finite impulse response (FIR) multirate time-delay model is initially built to describe the considered system. The problems of over-parameterization and the existence of both continuous model parameters and discrete time-delays have made the conventional maximum likelihood difficult to solve the considered problems. In order to handle these problems, the joint parameter and time-delay estimation for the LPV FIR multirate time-delay model are formulated in the expectation-maximization scheme, and the algorithm to estimate the model parameters and time-delays is derived, simultaneously based on multirate process data. The efficacy of the proposed method is verified through a numerical simulation and a practical chemical plant.

Modeling Traffic Conflicts between Pedestrians and Vehicles at Signalized Intersection Based on the Cellular Automata

2012 ◽  
Vol 178-181 ◽  
pp. 1881-1886
Author(s):  
Xiao Meng Li ◽  
Xue Dong Yan ◽  
Jiang Feng Wang
Keyword(s):  
Cellular Automata ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Intersection Safety ◽  
Vehicle Density ◽  
Conflict Model ◽  
Traffic Conflicts ◽  
Traffic Conflict ◽  
Pedestrian Crossing ◽  
Main Factor

The traffic conflict between pedestrian and vehicle is a main factor that influences the intersection safety and capacity. In this paper, a conflict model that simulates the pedestrians and vehicles’ crossing behaviors when passing the pedestrian crossing area at signalized intersection is presented based on cellular automata method. Evolution rules for pedestrians, vehicles and conflicts between them are assigned. Four types of traffic conflict events and conflict areas are categorized and defined. On the basis of the simulation results, the pedestrian delay owning to traffic conflicts, the number of pedestrians’ conflicts, the conflict event and their relationships with the vehicle density as well as the pedestrian density are analyzed and discussed. This model reproduces realistic pedestrian-related traffic phenomenon effectively and can be used in more complex traffic environments at signalized intersections.

scholarly journals Development of an Optimization Traffic Signal Cycle Length Model for Signalized Intersections in China

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yao Wu ◽  
Jian Lu ◽  
Hong Chen ◽  
Haifei Yang
Keyword(s):  
Delay Time ◽  
Cycle Length ◽  
Primary Objective ◽  
Signalized Intersections ◽  
Traffic Signal ◽  
Delay Model ◽  
Traffic Conditions ◽  
Vehicle Delay ◽  
Pedestrian Crossing ◽  
Xi’An City

The primary objective of this study is to develop an optimization traffic signal cycle length model for signalized intersections. Traffic data were collected from 50 signalized intersections in Xi’an city. Using comprehensive delay data, the optimization cycle length model is re-recalibrated to the Chinese traffic conditions based on the Webster delay model. The result showed that the optimization cycle length model takes vehicle delay time, pedestrian crossing time, and drivers’ anxiety into consideration. To evaluate the effects of the optimization cycle length model, three intersections were selected for a simulation. The delay time and queue length based on the optimization cycle length model and the TRRL model were compared. It was found that the delay times and queue lengths with the optimization cycle length model were significantly smaller than those with the TRRL model. The results suggested that the optimization traffic signal cycle length model was more optimal than the TRRL model.

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