Pedestrian Delay Model Research Articles

Pedestrian delay models for compliant & non-compliant behaviour at signalized midblock crosswalks under mixed traffic conditions

The present study aimed to propose new pedestrian delay models for Signalized Midblock Crosswalks (SMC) for mixed traffic conditions. A detailed study of the literature revealed that most of the existing pedestrian delay models were developed for signalized intersections. Thus, the need for the study was established and data were collected at eight SMC in Hyderabad, one of the most densely populated metropolitan cities in India, using video-graphic technique. Two delay models were developed based on the compliance behaviour and non-compliance behaviour of pedestrians. Both models have two components i.e., waiting delay and crossing delay where the latter has two subset components i.e., frictional delay and pedestrian-vehicle interaction delay. The bidirectional effect (pedestrian-pedestrian interaction while crossing the road) of pedestrians was addressed as frictional delay while the non-compliance behaviour by pedestrians and vehicles was addressed as pedestrian-vehicle interaction delay in the present models. The waiting delay component was defined by modifying the Webster delay model for non-uniform pedestrian arrivals. The proposed delay models yielded an error of 5% and 7% for compliance behaviour model and non-compliance behaviour model respectively. The proposed models can be used for optimizing the signal timings and defining Level of Service (LOS) of facilities.

Comparison of Pedestrian Delay Models at Signalized Midblock Crossings Under Mixed Traffic Conditions

In the field of transportation engineering, one of the most important factors for the traffic engineers and road users (pedestrian and vehicle) is the delay which governs the LOS of a facility. Past studies shows that various delay models like HCM, Webster, and Austroads work well for the homogeneous traffic conditions. However, Limited studies were done on mixed traffic conditions like in India and in other developing countries. Apart from that, all the models were developed based on the conditions of signalized intersection whereas signalized midblock crosswalks were completely overlooked by the researchers. The present study aims to compare pedestrian field delay at signalized midblock sections with the existing models. Six mid-block crossings have been selected from Hyderabad, India and data was collected using video-graphic technique. Field Pedestrian waiting delays were measured by plotting queue length against cycle time and area under the curve was calculated using Simpson's 1/3rd rule. Field crossing delay was calculated as the difference between actual crossing time and ideal crossing time. The performance of all the models were evaluated using t-test and other performance indices like MAPE, RMSE and R2. It was observed from the statistical tests that there is a significant difference between the means of field delay and delay by existing models. Also all the existing models yielded an error of more than 20% with an R2 value of less than 0.3. Calibrated results can be used in the modelling of new pedestrian delay for signalized midblock crosswalks.

Discussions on pedestrian delay models and applications at signalized crosswalks

Discussions on pedestrian delay models and applications at signalized crosswalks

Analysis of Pedestrian Crossing Behaviour at Roundabout

Studies looking at roundabout safety have generally focused on drivers, overlooking the importance of the safety of vulnerable users such as pedestrians. Crosswalks at roundabouts are useful for pedestrians and increase safety. They should be placed to attract the maximum number of pedestrians, who would otherwise cross the road haphazardly. In this study, we analyse the street crossing behaviour of non-elderly and elderly pedestrians by filming their crossing behaviour with video cameras at 4 selected roundabouts. Data on pedestrian behaviour, including kerb delay and crossing conditions (legal and illegal), are then extracted and analysed.The crosswalks studied were intentionally chosen with different setback distances, to understand pedestrians’ willingness to deviate from the linear path when there are no bollards or other devices forcing them to cross on the crosswalk. Most of the pedestrians observed did not stop to wait for a passing vehicle but they continued to walk "zigzagging" among cars. The CHAID (Chi-square Automatic Interaction Detector) decision tree was used to identify the significant factors leading to increased likelihood of illegal crossing and highest kerb delay values. Path analysis was used to test the direct effect of independent variables on dependent variables.For Crossing condition, CHAID analysis results showed that the more significant variables were: type of street (main or secondary), type of pedestrian (non-elderly; elderly), and distance of intersection from roundabout. While the analysis of PATH shows a direct relationship between illegal crossings and secondary streets and a negative relationship with Crosswalk length. For kerb delay, the results of the CHAID analysis showed that there was only one significant variable: type of pedestrian. While the PATH analysis highlighted that elderly pedestrians were strong directly associated with higher Kerb delay values and that also secondary streets were directly associated with higher kerb delay.This study can help researchers and practitioners understand pedestrian crossing behaviour at roundabouts, both to develop pedestrian delay models and to define measures to improve pedestrian safety.

Pedestrian Delay Model for Continuous Flow Intersections under Three Design Patterns

In order to accurately evaluate the level of service of pedestrians and provide the basis for the optimized design, the pedestrian delay of the continuous flow intersection was analyzed. According to the characteristics of streams of pedestrians’ arriving and leaving, the pedestrian delay models of different directions (namely, straight and diagonal) were established for three pedestrian passing patterns of the continuous flow intersection. The accuracy of the models was verified by VISSIM. The deviation was less than 3%. The effects of three key factors, namely, the vehicle demands, pedestrian demands and percentage of diagonal crossing, on the delay of the pedestrian under three modes were discussed by sensitivity analysis. The results show that the traditional pedestrian passing pattern mainly applies on the conditions that vehicle and pedestrian demands are low. The pattern of interspersed pedestrian passing is mainly applicable to the conditions of high vehicle and pedestrian demands. Although the pattern of exclusive pedestrian passing phase was least selected as the optimal design, it can apply to traffic demand fluctuating condition for its insensitive to volume and pedestrian demand pattern.

Modeling Pedestrian Level of Service at Signalized Intersection Under Mixed Traffic Conditions

Developing countries such as India need to have the proper pedestrian level of service (PLOS) criteria for various facilities to help in planning, designing, and maintaining pedestrian facilities. Thus, the objective of this study was to develop a suitable method for estimating the PLOS model under mixed traffic conditions and also to define threshold values for PLOS classification at signalized intersections. First, the data were collected with video and a user perceptions survey at eight selected signalized intersections in Mumbai, India. Second, pedestrian crossing behaviors were modeled according to arrival pattern, crossing speed, noncompliance behavior, and pedestrian–vehicular interaction. Third, a pedestrian delay model was proposed by considering crossing behavior variations and subsequent validation with field data. Fourth, significant variables were identified on the basis of the Pearson’s correlation test with user’s perceptions score. Fifth, the conventional linear regression (CLR) technique was explored to determine the PLOS. To overcome the limitations of the CLR technique, fuzzy linear regression (FLR) was done to develop a PLOS model that fits mixed traffic conditions in India. Two models were validated, and their statistical performance results indicate that the FLR model predicts the PLOS score more precisely. Finally, k-means and fuzzy C-means (FCM) clustering techniques were applied to classify the PLOS score, and the results were compared by time complexity value and field values. The performance evaluation results indicate that the k-means method saves time but fails to produce more reliable threshold values, and the FCM method produces more accurate and efficient threshold values for the PLOS score at signalized intersections under mixed traffic conditions.

A new approach to estimate pedestrian delay at signalized intersections

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.

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

The objectives of this study were to identify the factors affecting the pedestrian level of service (LOS) at signalized intersection crosswalks under mixed traffic conditions and to develop a suitable method for estimating pedestrian LOS. The important factors influencing pedestrian LOS at crosswalks were summarized: turning traffic, through traffic, number of pedestrians, and pedestrian delay. In the Highway Capacity Manual method, pedestrian delay can be calculated by Webster's delay model, which assumes that pedestrians arrive at a uniform rate and comply with the signal at an intersection. However, that assumption is not suitable for the Chinese scenario. A pedestrian delay model was developed by considering nonuniform arrival rates and noncompliant behavior under mixed traffic conditions. The data collected by video and a questionnaire survey include information on 1,257 participants' real-time sense of comfort and safety when crossing five selected intersections and on the operational characteristics of the intersections. With perceived LOS as a dependent variable, Pearson correlation analysis and linear regression techniques were explored to determine the significant factors affecting LOS. To overcome the limitations of linear regression techniques, cumulative logistic regression was done to develop a model that fits mixed traffic conditions in China—a model that can predict the probability of responses within each LOS on the basis of a combination of explanatory variables. The results showed that the cumulative logistic model fit the survey data better than the linear regression model and produces LOS A for the crosswalks.

Empirical analysis of pedestrian delay models at urban intersections

Signalized crosswalks are useful pedestrian facilities but complexities in geometry and configuration arise, especially in congested urban areas, directly affecting safety, cycle length and delay. Universal design criteria are not dealt with by manuals. Scientific literature has proven that pedestrians look for the shortest path at crosswalks, sometimes even adopting unsafe behaviour. On the other hand, drivers’ habits are scarcely bothered by pedestrian signage. The analysis of pedestrians’ cognitive path and choices is fundamental as well as the prediction of irresponsible actions. Delay is a widely adopted parameter to assess pedestrian Level of Service. In this work, a comparison among renowned models to estimate pedestrian delay at signalized crosswalk is set and double-checked with a field study in the city of Bologna – Italy.

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

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.

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.

Pedestrian Delay at Signalized Intersections with a Two-Stage Crossing Design

An improved pedestrian delay model was developed for signalized intersections with a two-stage crossing design. This model provides a timely enhancement tool for the Highway Capacity Manual for conducting multimodal-oriented level of service assessments at signalized intersections with unconventional pedestrian crossings. The proposed model is presented in a general form that provides estimation of three portions of pedestrian delay involved in a two-stage crossing: the first-stage delay; the second-stage delay for pedestrians who crossed during the Walk phase of the first stage; and the second-stage delay for pedestrians who crossed during the flashing Don't Walk and Stop phases of the first stage. The model was validated through microscopic simulation under a wide range of traffic scenarios. Statistical analysis suggests that the proposed model is able to give satisfying results (R2 = 99.9%, p-value = .000). The model can be applied in various cases knowing some basic input parameters and variables.

Mixed-Priority Pedestrian Delay Models at Single-Lane Roundabouts

This paper presents an approach for developing mixed-priority pedestrian delay models at single-lane roundabouts using behavioral crossing data. Mixed-priority refers to crosswalk operations where drivers sometimes yield to create crossing opportunities, but where pedestrians sometimes have to rely on their judgment of gaps in traffic to cross the street. The models use probabilistic behavioral parameters measured in controlled pedestrian crossings by blind pedestrians as part of NCHRP project 3-78a. While blind pedestrians clearly represent a special population of pedestrians, the developed delay model is structured to be applicable to any pedestrian population. Delay is predicted as a function of the probability of encountering a crossing opportunity in the form of a yield or crossable gap, and the probability of utilizing that opportunity, which are combined to produce an overall probability of crossing. The paper presents the theoretical approach to estimating the probability parameters and uses a multi-linear log-transformed regression approach to predict the average pedestrian delay. The final delay model explains 64% of the variability in the observed data and therefore represents a reasonable model for predicting pedestrian delay at single-lane roundabouts. The paper concludes with a discussion of how agencies can estimate the underlying probability parameters for existing or proposed roundabouts using empirical and theoretical approaches, and how pedestrian crossing treatments can be used in the context of the model to reduce average pedestrian delay. The research is important in light of the ongoing debate of the accessibility of modern roundabouts to pedestrians who are blind.

Validation of HCM Pedestrian Delay Model for Interrupted Facilities

The Highway Capacity Manual (HCM) 2000 equation for pedestrian delay at signalized intersections assumes that pedestrian arrivals at those intersections are random. However, if a significant percentage of those pedestrians are arriving from an upstream coordinated signal, the arrival rate may not be random and the average delay may be quite different from that which would be predicted. Two studies were conducted to test the HCM model for pedestrian delay at coordinated signalized intersections. Data collected at six intersections in St. Louis indicated that pedestrian arrivals at these locations were significantly affected by upstream signals. A study of delays along an arterial in Columbia, Mo. showed that 24 out of 30 data sets had delays that were significantly different from those expected from the HCM 2000 delay equations. 29 of the 30 data sets had variances of delay significantly lower than expected if arrivals were random. The results from these studies indicate that delay calculations for signalized intersections in coordinated systems should recognize the effect of signal coordination.

Pedestrian delay estimation at signalized intersections in developing cities

This paper proposes a pedestrian delay model suitable for signalized intersections in developing cities, on the basis of a field study conducted in Xi’an, China. The field study consisted of two parts: Part I involved only one crosswalk, and the signal cycle was divided into 13 subphases; Part II involved 13 crosswalks, but the signal cycles were only divided into green phases and non-green phases. It was found that pedestrian arrival rates were not uniform throughout cycles; pedestrians arriving during green phases might also receive delays; pedestrian signal non-compliance was so severe that delays were greatly reduced, but non-complying pedestrians might still receive delays; and for pedestrians walking different directions, though the relationships between average delay and arrival subphase were different, the overall average delays were almost the same. On the basis of the field study results, some assumptions are made about the relationship between average pedestrian delay and arrival subphase, and a new model is developed to estimate pedestrian delays at signalized intersections. The model is validated using the field data, and the validation results indicate that in Xi’an the new model provides much more accurate estimation than the existing models.

Modeling of Pedestrian Delays with Pulsed Vehicular Traffic Flow

The phenomenon of the bunching of urban traffic is considered together with a mathematical model for the associated problem of the delay to pedestrians crossing a traffic stream. The approach used is also applicable to estimating delay to a single vehicle at a priority intersection and to merging vehicular traffic. Many pedestrian delay models include the assumption that successive vehicular headways are independent and identically distributed random variables. Such models may not be appropriate where vehicles form bunches—as occurs, for example, near traffic signals. Modeling of pedestrian delay is considered in two parts: the delay to pedestrians arriving during a vehicular bunch, and delay to those arriving during the random flow between bunches. These two parts are considered in combination to obtain overall delay. Three field surveys were conducted in metropolitan Sydney. Useable data were obtained on 4,350 headways and 252 crossing pedestrians on major arterial roads. The field data were used to assess the validity and accuracy of the proposed model. They support the theoretical model and suggest that, under certain conditions, it provides a more accurate estimation of pedestrian delays downstream of traffic signals than do some existing models, such as Adams' (1936) model.