Uncontrolled Intersections Research Articles

Study on Uncontrolled Intersection Under Mixed Traffic Condition-A Review

Every people in the world can access the road for the transportation purpose. Several traffic signs and signals are placed in order, to maintain safety for the people. Some places which don’t have the proper signals at the intersection might lead to cause more accidents and that kind of intersection are called as uncontrolled intersection. When several type of vehicles sharing and moves in a same carriage width without any gap between vehicles without any proper lane discipline is known as mixed traffic condition. Due to these accidents many people lose their life and many properties are also damaged. Several studies are being done by many literates about the uncontrolled intersection and it is available in the literature under mixed traffic condition for finding out the causes and some remedial measure were provided in those studies. Some of the study indicates about the Gap acceptance, Conflicts, pedestrian crossing behaviour, occupation time of the vehicle and so on. In this study we are going to discuss about those literatures and to give some remedial measures for the conflicts that occur in the uncontrolled intersection under mixed traffic condition.

Pedestrian interaction with automated vehicles at uncontrolled intersections

Automated Vehicles (AVs) are being developed rapidly and tested on public roads, but pedestrians’ interaction with AV is not comprehensively understood or thoroughly investigated to ensure safe operations and the public’s trust of AVs. In this study, we aimed to provide another research evidence to enhance such understanding with the use of external interfaces for facilitating the interaction between pedestrians and AVs. We developed five external interfaces, including text, symbol, animated-eye, a combination of text and symbol, and speed. These interfaces communicated five types of information, including (1) intent of AV; 2) advice to pedestrians of what to do, (3) AV’s awareness of pedestrians, (4) combination of intent and advice, and (5) vehicle movement (i.e., speed). We tested the interfaces through two field studies at uncontrolled intersections with crosswalks. The Wizard of Oz method was used, in which an experimenter worked as a driver in an instrumented vehicle and wore an outfit to be invisible to the pedestrians, thus rendering the set-up to simulate an AV interacting with a pedestrian. The interfaces were displayed on an LED panel mounted on the AV. Results showed that the AV’s external interface did not change pedestrians’ response time in comparison with the baseline without any interface. There was no statistically significant difference in response time among the external interfaces either. According to the post-experimental interview, vehicle movement pattern (e.g., vehicle speed) continued to be a significant cue for pedestrians to decide when to cross the intersections. Participants perceived the communication of the AV’s intent and vehicle speed as more beneficial than the communication of AV’s awareness. The subjective ratings showed positive effects of those interfaces that were easy to understand (e.g., text interface and speed interface), which also helped pedestrians feel safer when interacting with the AV.

Target Vehicle Motion Prediction-Based Motion Planning Framework for Autonomous Driving in Uncontrolled Intersections

This paper presents a motion-planning framework for urban autonomous driving at uncontrolled intersections. The intention and future state of the target vehicles are predicted using information obtained from the environment sensors. The target state prediction module employs an Interacting Multiple Model (IMM) filter to infer the intention of targets. The prediction results of each model of the IMM filter are fused to predict the future state of targets. The proposed predictor uses the intelligent driver model based-driver behavior model to construct the local filter of IMM. The driving mode decision is realized as a state machine consisting of two phases, ‘Approach’ and ‘Risk Management’. The risk management phase is composed of two sub-modes, ‘Cross’ and ‘Yield’. The state transition conditions between phases and modes are defined by introducing the concepts of ‘Critical gap’ and ‘Follow-up gap’. Based on the determined driving mode, the motion planning module consists of two sub-modules for each phase. The required deceleration determination for the approach phase is proposed to consider the occluded region in order to prevent inevitable collisions caused by fast approaches. The model predictive controller for the risk management phase is designed to determine the desired acceleration to guarantee safety and prevent unnecessary deceleration simultaneously. Both computer simulation studies and vehicle tests are conducted to evaluate the proposed framework. The results indicate that the proposed framework ensures the safety at uncontrolled intersections with a driving pattern similar to that of a driver.

The Permeable Performance Testing of the Level Intersection – Case Study

The article deals with the assessment of the permeable performance of a level intersection. The case study uses the results of our own directional intersection traffic survey, supported by the outputs of the national traffic census and forecasts of traffic development in the given road section. The assessment of the design of the intersection solution is performed alternatively without a motorway section and after its commissioning. The main goal of case study is to analyze the traffic characteristics of the original level of uncontrolled intersection and to assess the proposal of a new transport organization with the intention to increase the safety and fluidity of traffic as the main prerequisite for increasing the resilience of the intersection.

Retracted: Uncontrolled Intersection Operational Assessment under Mixed Traffic Conditions

AbstractThe objective of this paper is to develop motorized level of service models using advanced heuristic techniques like functional networks, ordered probit analysis, and multivariate autoregre...

TECHNICAL ANALYSIS OF VEHICLE DRIVERS’ ACTIONS AT UNCONTROLLED INTERSECTIONS WHILE TURNING LEFT

The questions which arise at experts while carrying out road accident analysis (forensic expert examination) during technical analysis of vehicle drivers’ actions at uncontrolled intersections, in cases when turning left at a separating lawn line a traffic sign “Yield” is installed, and a traffic sign “Priority Road” is installed at the intersection facing the direction of vehicle movement which turns left, are considered. When technically evaluating drivers actions at an uncontrolled intersection in accordance with the requirements of Traffic Rules of Ukraine, forensic experts who make up a forensic report on the results of road accident analysis wonder: “How to evaluate the driver’s actions who performs a turning maneuver to the left at uncontrolled intersection, when a traffic sign ‘Yield’ is installed at a separating lawn line while turning left, and a traffic sign “Priority Road” is installed at the intersection facing the direction of vehicle movement where the vehicle turns left. Technical analysis of the driver actions who turns left at an uncontrolled intersection should be carried out in accordance with the requirements of paragraphs 10.1 and 16.13 of Traffic Rules of Ukraine. This is due to the fact that the presence of a traffic sign 2.3 “Priority Road” indicates the fact that a driver is on the priority road, and must give way to vehicles moving in the opposite direction heading straight or right when making a left turn.

RETRACTED ARTICLE: Motorized Level of Service Classification for Urban Uncontrolled Intersections

Service and total delay are considered for classifying MLOS and intersections, respectively. GPS is used to collect travel time and speed data for turning movements that are transformed into average delay values. Thirteen junctions from eight different cities in India form the dataset. Divisive followed by agglomerative clustering (DAC-HAC) algorithm is applied as a two-step process for obtaining the service and total delay ranges. Validation of clusters is performed based on the Davies-Bouldin score, Calinski-Harabasz index, and Silhouette gaps. Based on DAC-HAC, uncontrolled intersections are classified into six categories (Cat-I, II, III, IV, V, and VI). Results indicate MLOS classes “D”, “E” and “F” have significantly higher service delay ranges as compared to Highway capacity manual “control” delay ranges indicating mixed traffic conditions. Most of the uncontrolled intersections under mixed traffic fall under Cat-IV, V, and VI, having higher total delay ranges (> 60 s/ vehicle/ approach). Finally, validation of the clustering results is done for geometric and roadside environmental features.

User-satisfaction based operational evaluation for uncontrolled intersections under mixed traffic

The objective of this study is to assess operational performance of uncontrolled intersections by creating motorized level of service models using advanced heuristic techniques like functional networks, ordered Probit, ordered Logit, and multivariate auto-regressive spline for uncontrolled intersections under mixed traffic conditions. A novel “Influence area” method for critical gap and follow-up-time measurement is also developed. Over 7000 useful uncontrolled intersections, motorized driver responses are collected based on user satisfaction scores (1 for excellent to 6 for very bad). Eight variables with high significance (<0.001) effects on perceived scores from Spearman’s correlation technique are modelled. According to the sensitivity analysis, analogous to the proposed functional network model, volume to capacity ratio (highest effect), percentage of on-street parking (second highest effect) and service delay (third highest effect) showed superlative sensitivity towards level of service predictions at uncontrolled intersections compared to other parameters. The imperative outcomes of this research may help transport planners and traffic engineers to quantify operational evaluation of uncontrolled intersections and take crucial decisions towards their improvement.

Delay and driver turning time evaluation for uncontrolled intersections under diverse traffic operational situations

This study estimates mean service delay for turning movements with significant emphasis on a proposal of total delay models using microscopic analysis of travel time data under indiscipline driver behavior. Field service delay estimates are validated using microsimulation for all the turning movements. The authors utilized a manual video graphic technique for data collection of thirteen uncontrolled intersections from all over India. Conflicting flow rate is determined for a certain number of conflicting vehicles as obtained for subject right and left-turning vehicles. Driver turning time for motions concerning vehicular classifications is determined. Moreover, the effects of service delay and oncoming traffic flow on turning driver waiting time are investigated. Validation of service delay is also done against delay estimated using effective capacity (Ci) for the “Four-wheeler SUV” stream. It is validated that the conflict technique can predict 52% of field estimated service delays with a sensitivity of as low as 3.0 seconds/ vehicle/ approach for various traffic streams.

Game-Theoretic Modeling of Multi-Vehicle Interactions at Uncontrolled Intersections

Motivated by the need for simulation tools for testing, verification and validation of autonomous driving systems that operate in traffic consisting of both autonomous and human-driven vehicles, we propose a game-theoretic framework for modeling the interactive behavior of vehicles at uncontrolled intersections. The proposed vehicle interaction model is based on a novel formulation of dynamic games with multiple concurrent leader-follower pairs, induced from common traffic rules. Based on simulation results for various intersection scenarios, we show that the model exhibits reasonable behavior expected in traffic, including the capability of reproducing scenarios extracted from real-world traffic data and reasonable performance in resolving traffic conflicts. The model is further validated based on the level-of-service traffic quality rating system and demonstrates manageable computational complexity compared to traditional multi-player game-theoretic models.

Evaluation of pedestrian safety in unsignalized T and X – Intersections through comparison of the frequency and severity of pedestrian conflicts

Accidents have an increasing trend during the last decades leading to the importance of safety analysis of traffic facilities. There is a lack of quantity and quality of crash information in nations like India. Conflicts based analysis is better than crash based analysis in these cases. This paper aims to compare the safety of T and X-intersections using the Pedestrian Vehicle Conflicts Analysis (PVCA) method using data extracted from the videographic survey. This paper also aims at the use of Vissim and Surrogate Safety Assessment Models to suggest remedial measures. The PVCA method showed that controlled intersections are safer than uncontrolled intersections. The restriction of many pedestrian crossings to two crossings led to a reduction in conflicts as per the simulation results. It reduced the pedestrian conflicts at the T-intersection by 24.11 percent and X-intersection by 31.46 percent. A practical option to reduce conflicts is the prohibition of jaywalking within the influence area of an intersection during peak hours.

Microscopic simulation based uncontrolled intersection performance assessment

Performance of an urban corridor comprising of urban streets, signalized and unsignalized intersections gets highly influenced by the level of traffic operations at the unsignalized intersections. Unsignalized intersections under mixed traffic behave in uncontrolled manner due to lack of stop or yield signage. This study aims at assessing performance of urban uncontrolled intersections. Number of conflicting vehicles and their flow rates were used to develop mathematical models for service delay. Field service delays from 13 selected intersections form India were estimated and validated using PARAMICS after calibration using real time video data. Mean service delay for turning movements are analysed based on microscopic field investigation of driver travel time under different driver behavior. Two different traffic operational scenarios considering four-wheeler SUV stream at three-legged and four-legged intersections are compared. A thorough statistical investigation indicated that the conflict technique can predict 52% of field estimated service delays with a sensitivity of as low as 3 s/vehicle/lane for various traffic streams. The service delay, driver turning time and queue length models suggested can be utilized by practicing engineers to estimate intersection capacity and level of service of turning movements for better traffic operational management.

Classification of Uncontrolled Intersections Using Hierarchical Clustering

This research helps define motorized level of service (MLOS) for different categories of uncontrolled intersections using mixed hierarchical clustering technique. Service and total delay has been considered for classifying MLOS and intersections, respectively. GPS is used to collect travel time and speed data for turning movements which are transformed to average delay values. Thirteen intersections from eight different cities in India form the dataset. Divisive followed by agglomerative clustering (DAC-HAC) algorithm is applied as a two-step process for obtaining the service and total delay ranges. Validation of clusters is performed based on Davies–Bouldin score, Calinski–Harabasz index and Silhouette gaps. Based on DAC-HAC, uncontrolled intersections are classified into six categories (Cat-I, II, III, IV, V and VI). Results indicate MLOS classes “D”, “E” and “F” have significantly higher service delay ranges as compared to Highway Capacity Manual “control” delay ranges indicating mixed traffic conditions. Most of the uncontrolled intersections under mixed traffic fall under Cat-IV, V and VI having higher total delay ranges (greater than 60 s/vehicle/approach). Finally, validation of the clustering results is done for geometric and roadside environmental features.

Mathematical model of assessing urban planning decisions based on capital construction facilities location under the city plan

The article deals with the issues of placing large focal points over the city planning map. The topicality of this issue is described. The target function is determined; it takes into account the time losses of road users in the zone of the focal point influence and the amount of payments to budgets of different levels generated by the focal point functioning. The mathematical model that allows estimating time losses of road users is presented. The model has a special focus on the mechanism of transport demand development and on the assessment of crossing capacity based on the intensity of priority flows. The mathematical tools are developed; they allow calculating the financial consequences of the implementation of urban planning projects set out in the city plan, choosing focal points with the most beneficial influence on the municipal budget among the proposed ones, taking into account the minimum negative impact of the chosen focal points on the adjacent street-and-road network. Some particular cases of the transport demand development are discussed, for example, those of traffic management schemes that do not allow left-turn and through movements at uncontrolled intersections. The recommendations on the practical application of the target function when making urban transport decisions having regional and city significance are developed.

A multinomial logit model of motorcycle crash severity at Australian intersections

Introduction: Motorcyclists are exposed to more fatalities and severe injuries per mile of travel as compared to other vehicle drivers. Moreover, crashes that take place at intersections are more likely to result in serious or fatal injuries as compared to those that occur at non-intersections. Therefore, the purpose of this study is to evaluate the contributing factors to motorcycle crash severity at intersections. Method: A data set of 7,714 motorcycle crashes at intersections in the State of Victoria, Australia was analyzed over the period of 2006–2018. The multinomial logit model was used for evaluating the motorcycle crashes. The severity of motorcycle crashes was divided into three categories: minor injury, serious injury and fatal injury. The risk factors consisted of four major categories: motorcyclist characteristics, environmental characteristics, intersection characteristics and crash characteristics. Results: The results of the model demonstrated that certain factors increased the probability of fatal injuries. These factors were: motorcyclists aged over 59 years, weekend crashes, midnight/early morning crashes, morning rush hours crashes, multiple vehicles involved in the crash, t-intersections, crashes in towns, crashes in rural areas, stop or give-way intersections, roundabouts, and uncontrolled intersections. By contrast, factors such as female motorcyclists, snowy or stormy or foggy weather, rainy weather, evening rush hours crashes, and unpaved roads reduced the probability of fatal injuries. Practical Applications: The results from our study demonstrated that certain treatment measures for t-intersections may reduce the probability of fatal injuries. An effective way for improving the safety of stop or give-way intersections and uncontrolled intersections could be to convert them to all-way stop controls. Further, it is recommended to educate the older riders that with ageing, there are physiological changes that occur within the body which can increase both crash likelihood and injury severity.

Comparative Study of Pedestrian Crossing Behaviour at Uncontrolled Intersection and Midblock Locations

Understanding pedestrian-vehicular interaction and individual’s responsive behaviour under mixed traffic flow condition is a complex task. Individual’s perception and risk taking to cross the road varies with pedestrian characteristics (age, gender, luggage, and trip purpose), environmental characteristics, vehicular flow characteristics, land use type. The present study made a comparison of average pedestrian crossing speeds at different pedestrian crossing locations in medium size cities (Warangal and Thiruvananthapuram in India) under mixed traffic conditions to investigate the major factors affecting the pedestrian road crossing behaviour. Four hours of traffic data was collected using videography method from three uncontrolled intersections and two midblock locations. Significant test was done for crossing speeds between different locations and different pedestrian types. The statistical results showed that there is a significant difference between the crossing speed of midblock and intersection. Male and middle aged pedestrians have higher crossing speeds than female and young, old aged pedestrians respectively. It is concluded that the pedestrian crossing behaviour and their perception in risk taking varies with location, pedestrian’s characteristics. Simulation results showed that the average travel time delay changed with pedestrian age and gender and increased linearly with the pedestrian volume. The results can be used to understand pedestrian risk with vehicular flow.

Methodology for assessing required area for allocating centers of mass attraction in layout of urbanized territories and their impact on quality of traffic management in adjacent street and road network

The article discusses a methodology for assessing the required area for allocating centers of mass attraction. The subject of the study is the quality of traffic management in the adjacent street and road network. The authors examine the factors affecting the required area of the land plot for allocating centers of mass attraction in the layout of urbanized territories. They propose a mathematical model to estimate the size of the land plot required for the allocation of a permanent facility considering standard transport services provided for visitors arriving both by individual and public transport. The main factors of the proposed model are the traffic capacity of elements at uncontrolled intersections and the level of traffic service at them. Moreover, the authors suggest a block diagram for choosing the optimal place in the layout of urbanized territories for the allocation of mass attraction centers. The algorithm makes it possible to consider the required area for permanent facilities and elements of transport infrastructure (parking lot, stopping point, feeding intersections, etc.). Standard estimates for the area of land plots required for the allocation of transport infrastructure elements are included. In general, the proposed methodology represents a toolkit for the iterative process of choosing the optimal plot for the allocation of mass attraction centers in the layout of urbanized territories considering standard transport services provided for visitors.

Optimal Control for Connected and Autonomous Vehicles at Signal-Free Intersections

Abstract The development of connected and autonomous vehicles (CAVs) is one of the central aspects in the pathway towards future intelligent mobility systems. This paper addresses the problem of coordinating CAVs crossing an uncontrolled intersection so as to maintain safe and efficient traffic flow. The proposed control strategy is based on an optimal control framework that is formulated to minimize a weighted sum of total energy consumption and travel time of all CAVs by finding the optimal velocity trajectory of each vehicle. The design procedure starts with a proper formulation of the autonomous intersection crossing problem for CAVs, with various cases of energy recovery capability by the CAVs considered, to also investigate the influence of powertrain electrification on the intersection crossing problem. This yields an optimal control problem (OCP) with nonlinear and nonconvex dynamics and constraints. In order to ensure a rapid solution search and a unique global optimum, the OCP is reformulated via convex modeling techniques. Numerical results validate the effectiveness of the proposed approaches, while the trade-off between energy consumption and travel time is illustrated by Pareto optimal solutions.

Predictive modelling of injury severity in bicycle–motor vehicle collisions utilizing learning vector quantization: a case study of Britain’s cycling capital

Cambridge is truly known as Britain’s cycling capital but this has all been achieved without any real cycling infrastructure. Therefore, safety concern is the persistent barrier to cycling in Cambridge and its reputation is on the decline. Thus in response to the small number of the literatures on prediction models for cyclist related injuries, this study presents a modelling technique that applies learning vector quantization network to predict injury severity of cyclist. By discovering the potentially relationships between the injury levels and the factors that contribute to their generation, the model predicts the likelihood of the injury into two classes: slight and killed/seriously injured. The findings display that the effect of junction actions are almost double. Following this, T/staggered junction on an unclassified bend was discovered as UK's cycling capital’s “collision hotspots”. Subsequently, absence of a sufficient number of crossing facilities for cyclists had the largest effect. All other things being held near equal; rush hours during the weekdays, vehicle manoeuvre due to a poor turn and parked vehicle, going ahead bend manoeuvre by cyclist, limited modern protected bike lanes, wet road surface owing to inclement weather, vehicle blind spot and driving too close, visual distraction caused by adverse lighting condition and dazzle of sun, and junction control commonly at situations of give-way or uncontrolled intersections. The study then ends by maximising the overall predictive accuracy through contacting the most sensitive predictors into the model. Consequently, a professional road safety education needs to be delivered so as to crack down the human failure as a main contributory factor.

Pedestrian Moving Patterns during Potential Conflicts with 110 On-Road Driving Vehicles

As the most commonly seen vulnerable road users, protection and interaction with pedestrians are key functionalities in vehicle active safety and self-driving research areas. Development and evaluation of such systems require deeper understanding of pedestrian behaviors, especially motion patterns, in different driving environments. Traditionally, most of the pedestrian movement studies rely on fixed roadside cameras in specific road locations with higher pedestrian density, like intersections and junctions. Although these studies can provide information to describe pedestrian walking behavior and vehicle-pedestrian interactions in micro and macro levels, there are two main limitations. Firstly, pedestrian movement data are rarely collected from the vehicle’s point of view, which makes some critical variables difficult to be collected related to pedestrian initial appearance situation. Secondly, insufficient data are acquired to cover low- pedestrian-density road environments like mid-block, rural areas, and small un-controlled intersections. In this study, we focus on three important pedestrian movement variables including appearance distances, initial time-to-collision, and crossing speed under different driving and road scenarios. Based on a large-scale naturalistic driving study, crossing pedestrians were randomly captured in the scene videos from 110 passenger cars when potential ego-vehicle-to-pedestrian conflicts appeared during a one-year period. Motion data of these pedestrians were then analyzed to calculate the targeted behavior measurements, with the empirical results reported.