Safety Issues Of Red-light Running And Unprotected Left-turn At Signalized Intersections

Crashes categorized as running red light or left turning are most likely to occur at signalized intersections and resulted in substantial severe injuries and property damages. This dissertation mainly focused on these two types of vehicle crashes and the research methodology involved several perspectives. To examine the overall characteristics of red-light running and left-turning crashes, firstly, this study applied 1999-2001 Florida traffic crash data to investigate the accident propensity of three aspects of risk factors related to traffic environments, driver characteristics, and vehicle types. A quasi-induced exposure concept and statistical techniques including classification tree model and multiple logistic regression were used to perform this analysis. Secondly, the UCF driving simulator was applied to test the effect of a proposed new pavement marking countermeasure which purpose is to reduce the red-light running rate at signalized intersections. The simulation experiment results showed that the total red-light running rate with marking is significantly lower than that without marking. Moreover, deceleration rate of stopping drivers with marking for the higher speed limit are significantly less than those without marking. These findings are encouraging and suggesting that the pavement marking may result in safety enhancement as far as right-angle and rear-end traffic crashes at signalized intersections. Thirdly, geometric models to compute sight distances of unprotected left-turns were developed for different signalized intersection configurations including a straight approach leading to a straight one, a straight approach leading to a curved one, and a curved approach leading to a curved one. The models and related analyses can be used to layout intersection design or evaluate the sight distance problem of an existing intersection configuration to ensure safe left-turn maneuvers by drivers

Intersection Geometric Design and Operational Guidelines for Older Drivers and Pedestrians, Volume I: Final Report

DTFH61-92-C-00142This project was performed to develop guidelines for changes in the geometric design and operations at intersections with the greatest potential to aid in their use by older drivers and pedestrians. A literature review identified age-related diminished capabilities that affect performance at intersections, and examined current design standards and their adequacy for older road users. Problem identification studies (accident database analysis, task analysis, focus group discussions, field observations) were conducted to better define older persons' difficulties in intersection use, and an expert panel met to prioritize variables for more extensive laboratory and field studies later in the project. These studies subsequently focused on age (including both young-old and old-old groups) and the effects of opposite left-turn lane geometry (offset amount and direction), right-turn channelization and curb radius, and varying median pedestrian refuge island configurations, using both objective (performance) and subjective measures. A critique of the data obtained in these studies during a second expert panel meeting concluded that sufficient evidence exists to support guidelines for: (1) geometric design to ensure a minimum required sight distance for drivers turning left from a major roadway, and (2) operational changes to accommodate older drivers where (re)design of an intersection to meet sight distance requirements is not feasible. In addition, a revision of Case V in the AASHTO Green Book to determine sight distance requirements that reflect the perceptual task of gap judgment by a left-turning driver more accurately than the current assumptions in Case IIIB is recommended, and further research needs to enhance the safety and mobility of older road users at intersections are identified

A Model Based Approach to the Analysis of Intersection Conflicts and Collision Avoidance Systems

This dissertation studies the viability of driver assistance systems to improve the safety of „unprotected‟ left turns at signalized intersections. To achieve this, modeling and simulation have been conducted, including a driver model, with calibration and validation based on naturalistic driving data. A detailed analysis of the driving data has been conducted to reconstruct the vehicle trajectories in an automated manner. Particular challenges for this analysis include the development of automated detection of relevant events in a large database, automated estimation of sensor latencies, and the multiple application of Kalman filtering to fuse motion variables. A conflict analysis has been conducted to estimate the actual and predicted available gaps using the reconstructed vehicle trajectories. Monte Carlo simulations were conducted to create a large number of free left turn events in order to simulate a proposed driver assistance system and optimize safety performance. Optimization was conducted using multiobjective techniques which balance performance in terms of the rates of correct detections of conflicts, false alarms, and successful braking under the condition of correct detections based on Pareto optimality criteria. In this study, data to support the analysis was obtained from onboard instrumentation, where it was found essential to include detailed estimation of latencies between various sensors; after this, data fusion can be performed. It was found that high fidelity modeling of longitudinal control is critical to the safety system analysis. Also, it was found necessary to represent multiple levels of control, including visual preview and acceleration feedback. For the speed control reference, it was found that an “anticipated acceleration” can be used to define both straight braking events and free left turns; the driver may keep both options available during the intersection approach up to a critical decision point where the two references are equal. It was critical to the parametric optimization of the driver assistance system to take account of the need for warnings to be issued sufficiently early for the driver to respond; multiobjective design optimization was found to be an appropriate tool to include this requirement, as well as more typical requirements for involving false warnings.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89791/1/knobukaw_1.pd

Fostering Active Transportation In School Communities: A Literature Review And Case Study Of A Suburban Toronto High School

Active transportation is a growing area of interest in planning, particularly in relation to young people, who are walking and cycling considerably less throughout North America than in previous decades. Approaches to transportation planning have undergone major shifts in recent decades, moving away from car-oriented plans overseen by rational experts, towards plans that make space for walking, cycling, and public transit, and are informed by a chorus of voices and participants. The increasing prioritization of active transportation modes evolved from advocacy, feminist, and environmental planning theorists and other urban thinkers, and now features prominently in recent planning concepts such as Complete Streets, Walkability, and New Urbanism. The paper includes a multi-disciplinary review of literature on the subject of active transportation and young people. The first section places the subject matter in a planning context, including both planning theory and practice. The next section investigates various interventions to improve road safety for people who walk and ride bicycles, including lowering vehicle speeds on roadways, and improving pedestrian crossings and bicycle infrastructure. Finally, literature as it relates to young people and active transportation is investigated, looking at particular benefits of active transportation for youth, additional safety issues in regards to young pedestrians and cyclists, and behavioural patterns and potential for changing youth travel behaviour towards more active travel modes. The information is then applied to a study of West Hill Collegiate Institute, a public high school in suburban Scarborough, part of the amalgamated City of Toronto. Through a scan of the demographics and current conditions of the school's student catchment area, as well as consultation with students, a picture is drawn of a school and community where people walk only for very short trips, and very small numbers of people ride a bicycle, especially for daily commuting. Students have positive impressions about cycling and walking, but face barriers including distance, safety concerns,topography, and a lack of infrastructure. Using the information from the literature review, study and student consultation, a plan is developed in order to make active transportation easier, safer, and more welcoming in the area around the school. Recommendations in the plan work outward, starting with the school grounds directly, then considering the immediate neighbourhood nearby, and the outer section of the catchment area. The plan also includes ways to build educational and community programming and policies that support active transportation. While the plan can be used as a guide for future transportation changes in the area, it is also meant to be an consultation and educational tool to spur discussion about how to improve road safety and active transportation in the area under study. Ideally, the plan will be further refined through additional community engagement, and the attention of local governmental agencies. The model used for this plan provides a framework that can be used by other public high schools and their communities to develop plans that focus on youth and active transportation

Mobility and Aging: Older Drivers’ Visual Searching, Lane Keeping and Coordination

This thesis examined older drivers’ mobility and behaviour through comprehensive measurements of driver-vehicle-environment interaction and investigated the associations between driving behaviour and cognitive functions. Data were collected and analysed for 50 older drivers using eye tracking, GNSS tracking, and GIS. Results showed that poor selective attention, spatial ability and executive function in older drivers adversely affect lane keeping, visual search and coordination. Visual-motor coordination measure is sensitive and effective for driving assessment in older drivers

Identification of road user related risk factors, deliverable 4.1 of the H2020 project SafetyCube.

Safety CaUsation, Benefits and Efficiency (SafetyCube) is a European Commission supported Horizon 2020 project with the objective of developing an innovative road safety Decision Support System (DSS). The DSS will enable policy-makers and stakeholders to select and implement the most appropriate strategies, measures, and cost-effective approaches to reduce casualties of all road user types and all severities. This document is the first deliverable (4.1) of work package 4 which is dedicated to identifying and assessing human related risk factors and corresponding countermeasures as well as their effect on road safety. The focus of deliverable 4.1 is on identification and assessment of risk factors and describes the corresponding operational procedure and corresponding outcomes. The following steps have been carried out: Identification of human related risk factors – creation of a taxonomy Consultation of relevant stakeholders and policy papers for identification of topic with high priority (‘hot topics’) Systematic literature search and selection of relevant studies on identified risk factors •Coding of studies •Analysis of risk factors on basis of coded studies •Synopses of risk factors, including accident scenarios The core output of this task are synopses of risk factors which will be available through the DSS. Within the synopses, each risk factor was analysed systematically on basis of scientific studies and is further assigned to one of four levels of risk (marked with a colour code). Essential information of the more than 180 included studies were coded and will also be available in the database of the DSS. Furthermore, the synopses contain theoretical background on the risk factor and are prepared in different sections with different levels of detail for an academic as well as a non-academic audience. These sections are readable independently. It is important to note that the relationship between road safety and road user related risk factors is a difficult task. For some risk factors the available studies focused more on conditions of the behaviour (in which situations the behaviour is shown or which groups are more likely to show this behaviour) rather than the risk factor itself. Therefore, it cannot be concluded that those risk factors that have not often been studied or have to rely more indirect and arguably weaker methodologies, e.g. self-reports , do not increase the chance of a crash occurring. The following analysed risk factors were assessed as ‘risky’, ‘probably risky’ or ‘unclear’. No risk factors were identified as ‘probably not risky’. Risky Probably risky Unclear • Influenced driving – alcohol • Influenced Driving – drugs (legal & illegal) • Speeding and inappropriate speed • Traffic rule violations – red light running • Distraction – cell phone use (hand held) • Distraction – cell phone use (hands free) • Distraction – cell phone use (texting) • Fatigue – sleep disorders – sleep apnea • Risk taking – overtaking • Risk taking – close following behaviour • Insufficient knowledge and skills • Functional impairment – cognitive impairment • Functional impairment – vision loss • Diseases and disorders – diabetes • Personal factors – sensation seeking • Personal factors – ADHD • Emotions – anger, aggression • Fatigue – Not enough sleep/driving while tired • Distraction – conversation with passengers • Distraction – outside of vehicle • Distraction – cognitive overload and inattention • Functional impairment – hearing loss (few studies) • Observation errors (few studies) • Distraction – music – entertainment systems (many studies, mixed results) • Distraction – operating devices (many studies, mixed results) The next step in SafetyCube’s WP4 is to identify and assess the effectiveness of measures and to establish a link to the identified risk factors. The work of this first task indicates a set of risk factors that should be centre of attention when identifying corresponding road safety measures (category ‘risky’)

Evaluation of Real World Toll Plazas Using Driving Simulation

Toll plazas are becoming an essential part of the highway system, especially within the state of Florida. Many crashes reported on highways occur at toll plazas. A primary reason for many vehicle collisions happening at these facilities is the fact that each toll plaza agency has different design, signage and marking criteria. This, in turn, causes driver confusion and possible last minute weaving maneuvers. Even though the varying design of toll plazas is a clear highway safety factor, research in the field is very limited but expanding. This study focuses on one toll plaza, in particular the Dean Mainline Toll Plaza, located in Orlando, Florida. The toll plaza is located directly between two roads that are in close proximity of each other. Because of this, the toll plaza is very close to the on- and off- ramps, which can be even more confusing and stressful for a driver entering or leaving the highway. The purpose of this study is to evaluate the safety and efficiency of the Dean Mainline Toll Plaza in order to make recommendations to improve or maintain the current toll plaza design, as well as potentially contribute to a nationally set design standard for toll plazas. Using the NADS miniSimTM Simulator, 72 subjects were recruited, and each subject was asked to drive 3 scenarios that were randomly selected from a pool of 24 scenarios. The following factors were changed in order to study the driver\u27s behavior: signage and their location, pavement markings, distances between the toll plaza and ramps, and traffic conditions. All of these factors were altered and observed on five of the eight possible routes than can be taken through the toll plaza. The subjects were asked to complete questionnaires before and after all of the scenarios, as well as in between each driving scenario. These questionnaires included demographic characteristics, such as age, education, income, E-PASS ownership, etc. The data that were collected by the driving simulator and questionnaires were analyzed by ANOVA and multinomial logistic regression models. A positive relationship was found between non-urgent lane changing and the current real-world sign conditions prior to the toll plaza. Relationships were also found between the subjects\u27 speed in various locations and signage before the toll plaza and segment length after the toll plaza. Along with specified recommendations for future research in toll plaza safety, recommendations for the Dean Mainline Toll Plaza include maintaining the current signs and pavement markings, as they were found to be beneficial in drivers performing safe lane changing maneuvers

Development of a Human Factors Evaluation Procedure for Network-wide Road Safety Assessments

This work aimed at the definition of a Network-wide Road Safety Assessment procedure for two-lane two-way rural roads, namely Human Factors Evaluation procedure, which accounts for the influence of Human Factors in accidents triggering factors. The purpose of such a procedure is to provide an instrument to evaluate the risk of accidents occurrence because of wrong perceptions and expectations caused by the road. This often translates in operational errors, which may become driving errors that finally results in accidents, if uncorrected. The need of a Network-wide Road Safety Assessment procedure which accounts for Human Factors, together with an overview of considered methodologies, is discussed with a focus on Road Safety Inspection procedures. Indeed, visual site inspections and surveys allow to identify specific critical issue that may otherwise be missed while using big data analysis. Moreover, it has been decided that the Human Factors Evaluation procedure must follows the requirements of the updated 2008/96/EU directive (European Parliament and the Council, 2019). This will let it be a usable instrument for road agencies

A methodology for the design and evaluation of traffic control systems using microsimulation

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.Includes bibliographical references (p. 167-170).by Nageswar Rao V. Jonnalagadda.M.S