Pedestrian Delay Research Articles

Calculation features of traffic light regulation regimesat the signal group control

The differences between the existing technologies of traffic light control by phases and signal groups were determined in the paper. It was proved that the signal group control technology is more perfect and to a greater extent corresponds to the changing traffic conditions at intersections. Approach for compiling the traffic light regulation cycle structure based on the analysis of conflict of traffic and pedestrian flows, taking into account traffic volume, the number of road accidents in the conflict zones was defined. Also, in compiling the structure, the need to reduce the delays of vehicles and pedestrians was taken into account. Based on the signal group control technology, an algorithm for determining the parameters of traffic light regime, taking into account the traffic light cycle structure optimization, compiled for implementation on a computer was proposed. Using the developed approach will allow to increase the efficiency of traffic light regulation in both improving the traffic safety of vehicles and pedestrians and in reducing their delays before intersections.

Guided crowd dynamics via modified social force model

Pedestrian dynamics is of great theoretical significance for strategy design of emergency evacuation. Modification of pedestrian dynamics based on the social force model is presented to better reflect pedestrians’ behavioral characteristics in emergency. Specifically, the modified model can be used for guided crowd dynamics in large-scale public places such as subway stations and stadiums. This guided crowd model is validated by explicitly comparing its density–speed and density–flow diagrams with fundamental diagrams. Some social phenomena such as gathering, balance and conflicts are clearly observed in simulation, which further illustrate the effectiveness of the proposed modeling method. Also, time delay for pedestrians with time-dependent desired velocities is observed and explained using the established model in this paper. Furthermore, this guided crowd model is applied to the simulation system of Beijing South Railway Station for predictive evacuation experiments.

Multi-modal traffic signal control with priority, signal actuation and coordination

Both coordinated-actuated signal control systems and signal priority control systems have been widely deployed for the last few decades. However, these two control systems are often conflicting with each due to different control objectives. This paper aims to address the conflicting issues between actuated-coordination and multi-modal priority control. Enabled by vehicle-to-infrastructure (v2i) communication in Connected Vehicle Systems, priority eligible vehicles, such as emergency vehicles, transit buses, commercial trucks, and pedestrians are able to send request for priority messages to a traffic signal controller when approaching a signalized intersection. It is likely that multiple vehicles and pedestrians will send requests such that there may be multiple active requests at the same time. A request-based mixed-integer linear program (MILP) is formulated that explicitly accommodate multiple priority requests from different modes of vehicles and pedestrians while simultaneously considering coordination and vehicle actuation. Signal coordination is achieved by integrating virtual coordination requests for priority in the formulation. A penalty is added to the objective function when the signal coordination is not fulfilled. This “soft” signal coordination allows the signal plan to adjust itself to serve multiple priority requests that may be from different modes. The priority-optimal signal timing is responsive to real-time actuations of non-priority demand by allowing phases to extend and gap out using traditional vehicle actuation logic. The proposed control method is compared with state-of-practice transit signal priority (TSP) both under the optimized signal timing plans using microscopic traffic simulation. The simulation experiments show that the proposed control model is able to reduce average bus delay, average pedestrian delay, and average passenger car delay, especially for highly congested condition with a high frequency of transit vehicle priority requests.

Study on pedestrian crossing behavior at signalized intersections

A clear understanding of pedestrian crossing behavior under mixed traffic conditions is needed for providing necessary infrastructure and also for enhancing pedestrian safety at signalized intersections. This paper attempts to analyze the crossing behavior of pedestrians like crossing speed, compliance with signal, and pedestrian-vehicular interaction under mixed traffic conditions and to identify the influencing factors based on statistical tests. 775 pedestrian samples were observed from three signalized intersections in Mumbai, India for analyzing crossing behaviors and the significant factors affecting traffic signal compliance by pedestrians were identified by conducting Pearson's correlation coefficient test, ANOVA test, and Student t test. Factors influencing pedestrian crossing speed had been studied and a design crossing speed had been determined for old and adult pedestrians at 0.95 m/s and 1.12 m/s respectively. Logistic regression models had been developed in which the odds of pedestrian violation and interactions were modeled and verified. This study can help researchers and practitioners to understand pedestrian crossing behavior at signalized intersections and develop pedestrian delay models under mixed traffic conditions. Language: en

현장적용을 위한 연동형 반감응 신호제어 개발 및 분석

본 연구에서는 지방부 간선 또는 지선 축에서 효과적으로 사용 가능한 연동형 반감응 신호제어 알고리즘을 개발하고 이를 평가하였다. 연동형 반감응 신호제어에 대한 모의실험 결과를 살펴보면, 주 부 도로의 교통량 차이가 커질수록 연동형 반감응 신호제어의 지체가 최적화된 고정식 신호제어에 비해 감소하는 것을 확인하였다. 그러나 주부도로의 교통량이 같거나 전체 교통량이 많아지면 최적화된 고정식 신호제어의 지체가 더 낮게 나타났으며, 횡단 보행량이 많아질수록 차량 지체가 증가하는 것으로 확인되었다. 따라서 연동형 반감응 신호제어는 차량 교통량이 일정수준 이하인 곳에 적용하되, 횡단 보행량을 고려하여 적용지역을 선별해야 할 것이다. In this paper, Coordinated Semi-Actuated Signal Control algorithm was developed and evaluated. According to the analysis of simulation, the coordinated semi-actuated signal control led to reduced vehicle delay as the difference of traffic volume between major and minor streets was getting bigger. But when there was relatively high traffic volume, or the equivalent amount of traffic volume on major and minor streets, optimized pre-timed signal control was verified to lower delay times compared to coordinated semi-actuated signal control; however, it might increase pedestrian delay. Therefore, the coordinated semi-actuated signal control should be implemented at intersections where traffic volume is relatively low.

Optimal Methods of Traffic Control Systems for Pedestrians Crossing Signalized Intersection under Urban Overpasses

The vehicle delay is a key problem in intersection signal control system. Because there is enough security space for pedestrians under urban overpasses, the traffic control approach of pedestrians crossing signalized intersection may be further improved. To the above problems, this paper shows two-phase control method in pedestrians crossing signalized intersection under urban overpasses. According to this method, the vehicle delay affected by pedestrians crossing the signalized intersection is studied. Meanwhile, the variation trend of vehicle delay under different road widths are also analyzed. At last, an overpass is conducted for example analysis, and the result shows that this approach is practical and feasible for the special case of pedestrians crossing signal control intersection under urban overpasses, it can effectively reduce the pedestrian and vehicle delay.

New Methodology for Intersection Signal Timing Optimization to Simultaneously Minimize Vehicle and Pedestrian Delays

This study introduces a new methodology for signal timing optimization that is carried out by adjusting green splits of a.m. peak, p.m. peak, and rest of the day timing plans for each signalized intersection in the urban street network without changing the existing cycle length and signal coordination to minimize total vehicle and pedestrian delays per cycle. It contains a basic model that handles vehicle delays only and an enhanced model that simultaneously addresses vehicle and pedestrian delays using two different pedestrian delay estimation methods. Both models are incorporated into a high fidelity simulation-based regional travel demand forecasting model for detailed traffic assignments. A computational study is performed for methodology application using data on Chicago metropolitan area travel demand, traffic counts, geometric designs, and signal timing plans for major intersections in the Chicago central business district (CBD) area. A sensitivity analysis is conducted in the application of the enhanced model to examine the impacts of assigning different weights to vehicle and pedestrian delays on intersection vehicle travel time and delay reductions after signal timing optimization. The computational experiment reveals that after systemwide signal timing optimization, vehicle delays in the CBD area could reduce by 13% when considering only vehicle delays and by 5% when simultaneously considering vehicle and pedestrian delays.

Evaluating Driver and Pedestrian Behaviors at Enhanced, Multilane, Midblock Pedestrian Crossings

This study examined driver and pedestrian behaviors at two enhanced midblock pedestrian crossings in Portland, Oregon. One crossing was at a five-lane arterial with a posted speed of 35 mph and featured eight rectangular rapid flash beacon (RRFB) assemblies and a narrow median refuge. The other crossing was at a suburban arterial with a posted speed of 40 mph, four travel lanes, and a two-way left-turn lane. The crossing was enhanced with four RRFB assemblies and a median island with a Z-crossing, or Danish offset, designed to encourage pedestrians to face oncoming traffic before they completed the second stage of their crossing. Approximately 62 h of video was collected at the two locations. A total of 351 pedestrian crossings were analyzed for driver compliance (yielding) rates, pedestrian activation rates, pedestrian delay, and conflict avoidance maneuvers. The suburban arterial crossing was also evaluated to determine its effectiveness at diverting pedestrians to cross at the crossing instead of away from the crosswalk, as well as pedestrian compliance with the Z-crossing. The study found that average driver yield rates at both sites were slightly greater than 90% when the RRFB was activated, consistent with previous studies. RRFB actuation rates ranged from 83% to more than 90%. The results also showed that approximately 52% of all crossings at the marked crosswalk at the second location were made by diverted pedestrians and that the enhanced crossing captured about 82% of all crossings near the crosswalk. Finally, approximately 52% of the pedestrians who used the crosswalk followed the Z-crossing pattern through the median.

The Influence of Accumulation Area and the Length of Pedestrian Route on Functioning of Roundabouts with Traffic Signals

The paper presents issues related to the functioning of storage areas on roundabouts with traffic signals with high and very high traffic volumes. This kind of intersection is commonly used in the centres of Polish cities on multilane roads and fairly common in the case of tram lines running through a central island. The increase of traffic flow volumes on left turn and U-turn has made this type of roundabout difficult to operate. Small storage areas around central islands are critical places that significantly influence the capacity of this kind of intersection. The use of multiphase traffic signals causes major lengthening of crossing time for pedestrians which results in pedestrian delays at this kind of intersection. During the conducted analyses, microscopic models carried out in Transyt program, were used. They enabled the reconstruction of the traffic conditions and a few other important issues while assessing their capacity.

Impact of Intersection Design on Pedestrians’ Choice to Cross on Red

The existing research and modeling applications for predicting pedestrians’ decision to cross on red at signalized intersections have most commonly modeled this decision as a function of pedestrian characteristics (such as age and mobility restrictions), traffic conditions, and signal delay. For this study, field observations suggested that the physical configuration of the crosswalk should also be an important predictor of the decision to cross on red, because pedestrians should be less likely to cross on red at major intersections with longer crosswalks. In addition, the overall configuration and complexity of the signal also have an impact on signal compliance. The study tested these hypotheses by collecting video data of pedestrian behavior at signalized intersections in Washington, D.C., and by building a binary logit model to predict the probability of crossing on red. The study found that certain signal phases, such as protected left turns, were strongly correlated with a higher probability of crossing on red. The study also found that the length of crosswalks was inversely correlated with the probability of crossing on red. Through tests of the model's predictive accuracy under various specifications, the design variables (e.g., geometry and types of signal phases) were found to be key in improving the model's predictive ability. The findings offer insights for the design of signalized intersections and shed light on the complexity of the relationship between crossing on red and pedestrian safety, because some characteristics that are associated with a lower incidence of pedestrian crashes are also associated with more crossing on red.

Modeling Pedestrian Delay at Signalized Intersection Crosswalks Under Mixed Traffic Condition

Walking is one of the main and sustainable traffic mode in urban transportation, particularly in India because of the flexibility and mobility involved in it. Pedestrians are facing problems during crossing at signalized intersection crosswalks under mixed traffic condition. Of all the problems faced by pedestrians in signalized intersection crosswalks, pedestrian delay is the most important parameter and it is difficult to estimate. Keeping this as the motivation, this research has been undertaken with the aim of developing a pedestrian delay model for signalized intersection crosswalks. The required model parameters were extracted based on the videographic survey conducted at a typical four arm signalized intersection in Mumbai, India. Analysis of the field data yielded some notable observations as follows: pedestrians adjust their crossing speed based on the traffic condition at that particular time, pedestrian non uniform arrival pattern was observed, and some of the pedestrians were crossing the crosswalk during flashing red signal phase and red phase. Considering the above mentioned pedestrian crossing behavioral factors, a new delay model suitable for Indian condition was developed based on three factors such as waiting time delay, crossing time delay and pedestrian – vehicular interaction delay. Waiting time delay is based on signal red timing for pedestrians in waiting area, crossing time delay is based on pedestrian walking speed, and vehicular interaction delay is based on acceptable gap and walking speed. The proposed new delay model was validated with the field data from the Holkar junction, Mumbai, India and compared with existing models. This new pedestrian delay model can also be used to evaluate of pedestrian level of services at signalized intersections.

Optimization of pedestrian phase patterns at signalized intersections: a multi‐objective approach

SUMMARYThis paper presents a multi‐objective optimization model and its solution algorithm for optimization of pedestrian phase patterns, including the exclusive pedestrian phase (EPP) and the conventional two‐way crossing (TWC) at an intersection. The proposed model will determine the optimal pedestrian phase pattern and the corresponding signal timings at an intersection to best accommodate both vehicular traffic and pedestrian movements. The proposed model is unique with respect to the following three critical features: (1) proposing an unbiased performance index for comparison of EPP and TWC by explicitly modeling the pedestrian delay under the control of TWC and EPP; (2) developing a multi‐objective model to maximize the utilization of the available green time by vehicular traffic and pedestrian under both EPP or TWC; and (3) designing a genetic algorithm based heuristic algorithm to solve the model. Case study and sensitivity analysis results have shown the promising property of the proposed model to assist traffic practitioners, researchers, and authorities in properly selecting pedestrian phase patterns at signalized intersections. Copyright © 2013 John Wiley & Sons, Ltd.

Estimates of Pedestrian Crossing Delay based on Multiple Linear Regression and Application

Within the range of city traffic, a large number of intersections are out of control of traffic light, so the pedestrian delay and car delay, which are caused by the conflict between crossing pedestrian and right-turn cars, are very common. This article, from the pedestrian perspective, gives an analysis for the influence to pedestrian crossing delay made by right-turn cars and models the relationship between independent variables and dependent variable by fitting a linear equation to the observed data with multiple linear regression model. The independent variables includes right-turn car volume, speed, the number of pedestrians on the opposite side and the number of pedestrians on the same side. The dependent variable is pedestrian crossing delay.Then, parameters calibration is made through SPSS by stepwise regression. After the analysis of impact factors of pedestrian crossing delay, this paper gives a restrictive condition for setting exclusive right-turn phase, as when the car volume exceeds a threshold, aiming to provide certain theory basis for the management of city traffic and improve the intersection traffic capacity and service level.

Modeling Pedestrian Delay and Level of Service at Signalized Intersection Crosswalks under Mixed Traffic Conditions

The objectives of this study were to identify the factors affecting pedestrian level of service (LOS) at signalized intersection crosswalks under mixed traffic conditions and to propose a suitable method for estimating pedestrian LOS. The study attempted to develop a pedestrian LOS model for signalized intersection crosswalks in Mumbai, India, by using pedestrians’ perceptions of various influencing factors. The important factors considered to develop the model were turning traffic, through traffic, number of pedestrians, and pedestrian delay. Pedestrian delay is one of the key performance indicators for signalized intersection crosswalks; it is necessary to estimate delays accurately to assess LOS. As in the Highway Capacity Manual method, pedestrian delay can be calculated with the help of Webster's delay model, which assumes pedestrians arrive at a uniform rate at an intersection and all will comply with the signal; however, that assumption is not true for the Indian scenario. A pedestrian delay model for Indian conditions was developed by considering nonuniform arrival rate and signal noncompliance behavior. A video graphic technique was conducted for six selected crosswalks. A questionnaire survey was conducted to obtain the perceived LOS of pedestrians. Pedestrian delay was found with the use of the new model. A Pearson correlation analysis was done to find the significant factors that affect LOS. With perceived LOS as a dependent variable and significant factors as independent variables, stepwise regression was done to develop the model that fit for urban mixed traffic conditions.

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

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.

Signal Optimization Design of the Mid-Block Crosswalk

This paper proposes the traffic signal optimization design for the street crosswalk between coordinated adjacent intersections. The design has taken the pedestrian waiting tolerance limit time into consideration as one of the constraint conditions to obtain the pedestrian green phase duration. If the green phase duration is not sufficient for pedestrian crossing safety, the methods of twice crossing street or two chances of crossing can be applied according to different situations. The common red time of two intersections is analyzed to build delay functions by using of motorcade dispersion and traffic flow rate relationship, and timing optimization parameter can be worked out to minimize the total vehicle delay, thus determining signal phase difference. The result shows that this design may ensure the pedestrian safety and reduce the pedestrian delay.

Barrier-Free Ring Structures and Pedestrian Overlaps in Signalized Intersection Control

Compared with the ring-barrier framework used for ring structures (or phasing plans) in signalized control of intersections in the United States, the Dutch framework has no explicit barriers, but only a requirement to respect pairwise conflicts. This paper describes how ring structures can be modeled with pairwise conflicts as a starting point. Modeling techniques were extended to account for offset constraints such as leading pedestrian intervals in which the start or end of one traffic movement was constrained by the start or end of another one that was otherwise compatible. One practical drawback of the more flexible Dutch framework is that it permits so many more possible ring structures that it can be prohibitive to evaluate them all manually. Therefore, this paper describes VRIGEN, an automated method that overcomes this drawback by identifying and evaluating all possible ring structures. Finally, this paper presents several examples in which barrier-free ring designs allow signals to cycle more quickly and efficiently, with improvements in safety and delay for pedestrians and bicyclists. Most of these examples feature pedestrian phases that are allowed to overlap while their parent vehicular phases are not.

Influence of Midblock Pedestrian Crossings on Urban Street Capacity

The design of pedestrian crossings is a complex problem that must consider various factors. The basic criterion for determining the choice of a particular type of pedestrian crossing is traffic safety. To improve traffic safety, typical zebra crossings are being reconstructed, usually with implementation of refuge median islands or traffic signals. However, traffic engineers cannot properly take into account the influence of a type of pedestrian crossing on capacity and traffic progression as negative consequences for both pedestrians and vehicles. A study was conducted on the influence of various types of midblock pedestrian crossings on road capacity. Zebra crossings, crossings with refuge median islands, and signalized crosswalks were analyzed. For the evaluation, a simulation model was built in VISSIM and calibrated with research results on driver and pedestrian behavior. Empirical research confirmed the strong influence of regulations and pedestrian crossing types on the behavior of drivers. The results show that willingness to give right of way on urban streets influences capacity reduction and delays. Taking as a basic criterion overall delay for both vehicles and pedestrians, volume limits for implementation of a pedestrian crossing with a median island or traffic signals are proposed.

Using Cellular Automata to Investigate Pedestrian Conflicts with Vehicles in Crosswalk at Signalized Intersection

The operational efficiency and safety of pedestrian flows at intersections is an important aspect of urban traffic. Particularly, conflicts between pedestrians and vehicles in crosswalk are one of the most influential factors for intersection safety. This paper presents a cellular automata model that simulates pedestrian and vehicle crossing behaviors at signalized intersections. Through the simulation, we investigate the effects of different pedestrian signal timing and crosswalk widths on the crosswalk capacity, the number of traffic conflicts between pedestrians and vehicles, and pedestrian delay due to the conflicts. The simulation results indicate that the cellular automata is an effective simulation platform for investigating complex pedestrian‐related traffic phenomenon at signalized intersections.

Trenchless Infrastructure Construction Techniques Used in Colombia

AbstractThe use of traditional urban infrastructure construction techniques, particularly open-cut construction, is being used less and less because of the benefits offered by trenchless techniques. These techniques typically reduce the disruption and impact on both the environment (i.e., reduced greenhouse-gas emissions) and society (i.e., reduced traffic and pedestrian delays attributable to road and sidewalk closures). In Colombia, owners such as Empresas Publicas de Medellin E.S.P. and the Colombian Institute for Subterranean Infrastructure Technologies and Techniques have promoted the use of these technologies in urban areas. The primary techniques used in Colombia for installing and rehabilitating urban infrastructure are pipe bursting, horizontal directional drilling, cured-in-place pipe, and microtunneling. Automated decision support tools are available in Colombia to assist designers in selecting technically viable techniques. This paper describes the trenchless techniques used in Colombia, a bri...