1,004 research outputs found
GETTING ACTIVE WITH PASSIVE CROSSINGS: INVESTIGATING THE EFFICACY OF IN-VEHICLE AUDITORY ALERTS FOR RAIL ROAD CROSSINGS
Train-vehicle collisions at highway-rail grade crossings continue to be a major issue in the US and across the world. Installing additional hardware at individual crossings is expensive, time consuming, and potentially ineffective. To prevent recent trends in safety improvement from plateauing, experts are turning towards novel warning devices that can be applied to all crossings with minimal cost. In-vehicle auditory alerts (IVAAs) could potentially remedy many of the human factor issues related to crossing safety in a cost effective manner.
This thesis presents a series of experiments designing and testing an IVAA system for grade level railroad (RR) crossings. Study 1 collected subjective data on a pool of potential in-vehicle auditory alerts from 31 undergraduate participants. The type of IVAAs was varied along a number of dimensions (pitch, repetition, wave shape, wording, voice, etc.). Results from study 1 were used to design a prototype IVAA crossing notification system. A pilot study was conducted to calibrate the simulated driving scenario featuring multiple RR crossings and a compliance behavior coding procedure. Compliance behavior was operationalized as an amount of visual scanning and pedal depression.
Study 2 recruited 20 undergraduate participants to drive in a medium fidelity driving simulator featuring four types of RR crossings with and without IVAAs. Results suggest that IVAAs not only inform and remind drivers of how to comply at RR crossings, but also have a lasting effect on driver behavior after the IVAA is no longer presented. Compliance scores were highest among novel RR crossing visual warnings such as crossbucks featuring STOP or YIELD signs. Compliance was lowest for crossbucks alone and active gates in the off position. IVAAs had the largest impact on compliance scores at crossbucks and gates. The discussion includes implications for designing IVAA systems for RR crossings, and the potential implementation of prototype systems as a smartphone application
EFFECT OF SHORT-STORAGE HRGCs ON DRIVER DECISION BEHAVIOR AND SAFETY CONCERNS: REAL-WORLD ANALYSIS AND EXPERIMENTAL EVIDENCE
Vehicle-train collisions at highway-rail grade crossings (HRGCs) continue to be a safety concern, and despite improvements in warnings, many of these incidents are attributed to human error. In some cases, distractions other than railroad traffic, such as HRGCs with limited space between the railroad tracks and the highway intersection, may create additional cognitive burdens for drivers. We investigated the effect of HRGC type (short-storage vs. non-short storage) on driver attention and decision-making in two studies. In Study 1, we systematically analyzed 996 incidents from 2017-2019 from the Federal Railroad Administration’s Safety database. Driver decision making and outcomes were different depending on HRGC type, with more train strikes in short storage incidents, as opposed to vehicle strikes. Study 2 was a controlled lab experiment in which drivers identified safety concerns in driving images. Drivers reported more safety concerns, and rated them more important in images of short-storage HRGCs than non-short storage HRGCs. This pattern did not depend on their rural or urban driving experience. Eye-tracking analysis found some differences in search behavior depending on the type of HRGC. This research contributes to a new area of research in rail safety, as studies comparing the two types of HRGCs have previously not been done. Interventions for non-short-storage HRGCs may not apply to short-storage HRGCs if it is found that drivers approach them differently
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AN EVALUATION OF TRAFFIC CONTROL DEVICES AND DRIVER DISTRACTION ON DRIVER BEHAVIOR AT RAILWAY-HIGHWAY GRADE CROSSINGS
At-grade crossings (grade crossings) are those crossings in which any part of a roadway intersects with railroad tracks. Safety at these railroad-highway grade crossings is a major concern, with traffic control warning devices serving as the main mechanisms for improving safety.
There are three factors that influence a driver’s behavior at a given crossing. First, traffic control devices, including warning devices at the railroad-highway grade crossings, provide the driver with information whose impact will depend in part on the likelihood that the driver knows whether to glance in the direction of the device based on prior experience, and in part on what the driver understands the warning device to mean. Second, assuming that the driver identifies the warning, the driver’s prior knowledge influences his or her expectancy regarding various railroad-highway grade crossing situations and, therefore, the way in which the driver responds to the hazard presented by the crossing. Finally, the driver’s own physiological (e.g., impaired) and psychological (e.g., distracted) state will modify the role that conspicuity and expectancy have on the driver’s behavior.
This dissertation centers on the impact of distraction and the effect of traffic control and warning devices have on stopping behavior and glance behaviors at non-gated railroad-highway grade crossings and studies a possible countermeasure which when combined with traffic control and warning devices can mitigate the effects of distraction due to less than optimal glance patterns.
Two driving simulator experiments were conducted that arguably targeted the most critical need, in particular the need to identify the role that distraction has on the effectiveness of traffic control and warning devices at grade crossings. Ninety-nine participants were evaluated across two driving simulator experiments. For the first experiment, the role distraction plays in reducing the benefit of crossbuck and flashing lights was analyzed. Participants either engaged in a distracting task or did not engage. The secondary tasks included a mock cell phone conversation or an in-vehicle task where the participant driver was asked to change the radio station. The first experiment showed participants in all groups had trouble navigating the grade crossing environment thus pointing to the need to evaluate supplementary treatments which may benefit driver behavior at these crossings. The second simulator experiment evaluated the impact of the dynamic envelope pavement markings on driver glance pattern and behavior as they approached grade crossings while drivers also performed a distracting or non-distracting task. Results show that the addition of these markings can alert drivers of the presence of a grade crossing with anticipation, and as a result induce drivers to glance more and potentially stop in higher proportions than when the markings are not present
Feasibility of Evaluating Design Ideas for Reducing Vehicular Entrapment at Railroad Crossings Using a Laboratory Experiment
The number of accidents at railroad crossings is particularly high at places where streets run parallel to the railroad tracks. Existing grade crossings were investigated for potential problems and studied for design solutions. The present study reports progress of the first phase of a NJ DOT sponsored project. A laboratory experiment was designed for evaluating various design ideas before they are implemented in the second phase field study. The laboratory study used images taken from actual scenes of railroad crossings in New Jersey, instead of graphical drawings commonly used in driving simulations. Possible design ideas were edited using image processing software. Those design ideas were saved in different layers for generating design combinations which were superimposed on the background images to create virtual railroad crossing scenes. Nighttime images were also made possible by retouching the digital daytime images. Preliminary results of the in-lab experiment were presented. The experience learned from the current project indicates that use of actual images with superimposed design ideas is a cost-effective approach of evaluating and redesigning display layout
Driver Behavior at Railway-Highway Grade Crossings with Passive Traffic Control: A Driving Simulator Study
Research to evaluate driver behavior at railway-highway grade crossings with passive traffic control attempts to find an answer to a much debated subject. This study examines the difference in driver behavior and safety at several different types of passive traffic control at grade crossings utilizing a driving simulator. This project utilized the University of Tennessee’s high fidelity driving simulator to perform a study on passive highway-railway grade crossings. Although the crash rates at grade crossings have decreased in recent years, there is still more work to be done. Safety improvements can be made to both passive and active grade crossings. However, with increasingly tight budgets for transportation infrastructure, there is not enough money to upgrade and improve every grade crossing. Upgrading a passive grade crossing with flashing lights or gates is very expensive and can cost upwards of $400,000 in some parts of the country. This paper further investigates the use of STOP and YIELD signs as viable alternatives to upgrading a passive grade crossing to an active grade crossing. By utilizing a driving simulator, several variables were tested on sixty-four drivers in a safe environment. The driving simulator allowed tests to be run on grade crossings that range from safe to fairly unsafe. By varying the visibility at the crossing, which sign the driver saw at the crossing, the presence of a train, and the presence of other traffic, reasonable conclusions about the safety of various types of passive grade crossings are made
Effects of driver familiarity and prolonged or intermittent right-side failure on level crossing safety
This paper investigates the adverse effects of familiarity and human factors issues associated with the reliability of low-cost warning devices at level crossings. The driving simulator study featured a repetitive, low workload, monotonous driving task in which there were no failures of the level crossing (control) or prolonged or intermittent right-side failures (where the device reverts to a safe failure mode). The results of the experiment provided mixed support for the familiarity hypothesis. Four of the 23 participants collided with the train when it first appeared on trial 10 but safety margins increased from the first train to the next presentation of a train (trial 12). Contrary to expectations, the safety margins decreased with repeated right-side failure only for the intermittent condition. The limited head movement data showed that participants in the prolonged failure condition were more likely to turn their head to check for trains in the right-side failure trials than in earlier trials where there was no signal and no train. Few control participants turned their head to check for trains when no signal was presented. This research highlights the need to consider repetitive tasks and workload in experimental design and accident investigation at railway level crossings
Evaluating safety at railway level crossings with microsimulation modeling
Safety at railway level crossings (RLXs) is a worldwide issue that increasingly attracts the attention of relevant transport authorities, the rail industry, and the general public. The differences in the operation characteristics of varying types of warning devices, together with differences in crossing geometry, traffic, or train characteristics, leads to different driver behaviors at crossings. The aim of this study was to use traffic microsimulation modeling based on field video recording data to compare the safety performance of varying conventional RLX warning systems. The widely used microsimulation model VISSIM was modified to produce safety-related performance measures, namely, collision likelihood, delay, and queue length. The results showed that RLXs with an active warning system were safer than those with a passive sign by at least 17%. Integration of surrogate measures in conjunction with traffic simulation models determined which safety approach was more efficient for specified traffic and train volumes
Multiphysics Simulation of a Battery Electric Train Operation
The changeover from diesel driven multiple units to battery electric multiple units is a challenge for operators due
to the limited range of these trains. Therefore, in this paper a tool is developed and described that simulates the
entire operation of a battery electric train. The tool contains a model of the track, the vehicle, the timetable and the
environment. The model of the track is built on elevation profiles, radius information and speed limitation. The
vehicle model is derived from an electric multiple unit suitable for local and commuter train operation. To do
parametric studies or model different train units it is easily possible to change vehicle properties. Modeling the
timetable and the environment allows the simulation of an entire operation day. The overall simulation model was
validated and is consistent. Finally examples show the simulation possibilities and features of the tool
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