Rail Grade Crossings Research Articles

Difference in rural and urban driver-injury severities in highway–rail grade crossing accidents

Based on the Federal Railway Administration (FRA) database, there were 25,945 highway–rail crossing accidents in the United States between 2002 and 2011. With an extensive research, analysis results showed that there were substantial differences between rural and urban areas at highway–rail grade crossings. However, there is no published study specific on driver's injury severity at highway–rail grade crossings classified by area types. Using an ordered probit modelling approach, the study explores the determinants of driver-injury severity at rural highway–rail grade crossings compared with urban highway–rail grade crossings. The analysis found that motor vehicle driver's injury level at rural highway–rail grade crossing is extremely higher than urban area. Compared to collisions at urban area, collisions happened at rural area tend to result in more severe injuries. These crashes were more prevalent if vehicle drivers are driving at a high speed or the oncoming trains are high-speed. Moreover, highway–rail grade crossing accidents were more likely to occur at rural area without pavement and lighting.

Driver injury severity related to inclement weather at highway–rail grade crossings in the United States

ABSTRACTObjective: Previous studies on crash modeling at highway–rail grade crossings were aimed at exploring the factors that are likely to increase the crash frequencies at highway–rail grade crossings. In recent years, modeling driver's injury severity at highway–rail grade crossings has received interest. Because there were substantial differences among different weather conditions for driver's injury severity, this study attempts to explore the impact of weather influence on driver injury at highway–rail grade crossing.Method: Utilizing the most recent 10 years (2002–2011) of highway–rail grade crossing accident data, this study applied a mixed logit model to explore the determinants of driver injury severity under different weather conditions at highway–rail grade crossing.Results: Analysis results indicate that drivers' injury severity at highway–rail grade crossings is strongly different for different weather conditions. It was found that the factors significantly impacting driver injury severity at highway–rail grade crossings include motor vehicle speed, train speed, driver's age, gender, area type, lighting condition, highway pavement, traffic volume, and time of day.Conclusions: The findings of this study indicate that crashes are more prevalent if vehicle drivers are driving at high speed or the oncoming trains are high speed. Hence, a reduction in speed limit during inclement weather conditions could be particularly effective in moderating injury severity, allowing more reaction time for last-minute maneuvering and braking in moments before impacts. In addition, inclement weather-related crashes were more likely to occur in open areas and highway–rail grade crossings without pavement and lighting. Paved highway–rail grade crossings with installation of lights could be particularly effective in moderating injury severity.

Distracted Motor Vehicle Driving at Highway–Rail Grade Crossings

Distracted driving of a motor vehicle increases a driver's susceptibility to crash involvement. Such driving in the vicinity of highway–rail grade crossings (HRGCs) is especially perilous because the distracted driver may not be aware of the presence of an approaching train. Train-involved motor vehicle crashes invariably cause more severe injuries and greater property damage than other motor vehicle crashes. Because distracted driving at HRGCs is somewhat underresearched, the objectives of this research were to (a) investigate the occurrence of distracted motor vehicle driving at HRGCs, (b) identify characteristics of those distracted motorists, and (c) ascertain empirically factors associated with distracted driving at HRGCs. Data were collected with video recordings at six HRGCs in Nebraska and were statistically analyzed. Results showed that about one-third of drivers observed at HRGCs were distracted. The presence of intersecting roads near the crossings increased distracted driving. Drivers of multiunit trucks at HRGCs were less often distracted than other drivers at HRGCs. The presence of front-seat passengers in vehicles significantly contributed to driver distraction. Findings from the research support the need for driver education about distracted driving at HRGCs. Enforcement of distracted driving laws at HRGCs as well as strengthening of existing laws may also reduce instances of distracted driving at HRGCs.

Motor vehicle drivers’ injuries in train–motor vehicle crashes

The objectives of this research were to: (1) identify a more suitable model for modeling injury severity of motor vehicle drivers involved in train–motor vehicle crashes at highway–rail grade crossings from among three commonly used injury severity models and (2) to investigate factors associated with injury severity levels of motor vehicle drivers involved in train–motor vehicle crashes at such crossings. The 2009–2013 highway–rail grade crossing crash data and the national highway–rail crossing inventory data were combined to produce the analysis dataset. Four-year (2009–2012) data were used for model estimation while 2013 data were used for model validation. The three injury severity levels—fatal, injury and no injury—were based on the reported intensity of motor-vehicle drivers’ injuries at highway–rail grade crossings.The three injury severity models evaluated were: ordered probit, multinomial logit and random parameter logit. A comparison of the three models based on different criteria showed that the random parameter logit model and multinomial logit model were more suitable for injury severity analysis of motor vehicle drivers involved in crashes at highway–rail grade crossings. Some of the factors that increased the likelihood of more severe crashes included higher train and vehicle speeds, freight trains, older drivers, and female drivers. Where feasible, reducing train and motor vehicle speeds and nighttime lighting may help reduce injury severities of motor vehicle drivers.

Investigation of Train Warning Times and Gate Violations

The objective of this research was to investigate the relationship between train warning times and instances of motorists driving around fully deployed crossing gates at a highway–rail grade crossing equipped with median barriers (lane separators). The purpose of the median barriers is to deter motorists from driving around fully deployed gates. The premise for this research was the expectation that longer train warning times were accompanied by more numerous occurrences of driving around fully deployed crossing gates, notwithstanding the presence of median barriers. Data on motorists’ opportunities to drive around fully deployed crossing gates, actual instances of driving around those gates, warning times experienced by motorists, and some additional variables were collected at a study site during a 2-month period. The study site was equipped with median barriers on both sides of the crossing to discourage driving around fully deployed gates. Data analysis showed that after violation opportunities and certain other variables were controlled for, longer train warning times were indeed associated with more frequent instances of motorists driving around gates. The finding emphasizes the provision of adequate but not excessively long warning times at highway–rail grade crossings equipped with dual-quadrant gates. On the basis of the research findings, the paper provides options for improving safety at highway–rail grade crossings.

Severity of Injuries to Motor Vehicle Drivers at Highway–Rail Grade Crossings in the United States

There are approximately 240,000 highway–rail grade crossings in the United States. High crash frequencies at these locations have led to continued research in safety modeling. Existing crash models for highway–rail grade crossings can be classified into two categories: models for predicting accident frequency and models of the severity of driver injuries. The majority of these studies have focused on the first category. Few studies have focused on the severity of injuries to motor vehicle drivers at highway–rail grade crossings. The objective of this study was to determine the contributing factors that influence the severity of driver injuries in accidents at highway–rail grade crossings. Probit models showed that the following factors were significant: whether the crash occurred during the peak hour, weather, visibility, vehicle type, vehicle speed, annual average daily traffic, train speed, driver age and gender, area type, and type of highway pavement. A marginal effects analysis was also conducted to quantitatively interpret the marginal effects of the contributing factors on each severity level for the highway driver.

Effects of Three Advanced Devices on Preventing Crashes and Gate-Breaking Incidents at Highway–Rail Grade Crossings

This study investigated the effects of three advanced (i.e., engineering-based) devices—the obstacle detector, the LED train approaching indicator, and the law enforcement camera—on the prevention and reduction of specific types of traffic incidents at highway–rail grade crossings (HRGXs). The before-and-after effects of these three warning–control devices on the reduction of traffic collision and gate-breaking rates were evaluated. The interaction effects of these advanced devices in improving the safety of HRGXs were analyzed to identify the pure effect of each device and of different combinations of the devices. The empirical study used a 15-year data set on crashes and crossing inventory data that included the installation history of the three advanced devices. The numerical analysis results indicated that both the LED train approaching indicator and the law enforcement camera had different degrees of positive influence on improving the safety of an HRGX. The obstacle detector was found to be less effective in preventing traffic collisions, especially with regard to cost-effectiveness. Policy implications are discussed and future research directions are recommended.

The Impact of Removing Centerline Barriers from Highway–Rail Grade Crossings on Drivers’ Violations

The objective of this study was to assess changes in drivers’ unsafe maneuvers after removal of a centerline barrier installed at a dual-quadrant gated highway–rail grade crossing to improve safety. Such barriers limit drivers’ ability to pass around closed dual-quadrant gates, thereby reducing the possibility of motor vehicle collisions with trains. Highway safety-related appurtenances installed as countermeasures are usually left in place for extended periods, and the effects of their removal are not well researched. The removal of a barrier installed along the road centerline at a highway–rail grade crossing in Nebraska provided the opportunity to investigate the accompanying changes in drivers’ violations. Analysis of data collected before and after removal of the barrier showed that unsafe driver maneuvers increased after removal of the barrier. Specifically, passing around dual-quadrant gates with an oncoming train and making U turns to drive away from the closed crossing increased. The conclusion is that barrier removal contributed to the increase in unsafe driver maneuvers at the studied highway–rail grade crossing. Although limited in scope, this study lends credibility to the practice of not removing an effective countermeasure once installed, though regular maintenance is a requisite for continued effectiveness.

Signal Optimization at Urban Highway Rail Grade Crossings Using an Online Adaptive Priority Strategy

In urban areas, conventional transit priority systems (e.g., passive priority) present some problems, such as causing too many traffic delays and degradation of on line performance due to the lack of real-time data. The purpose of this study is to develop an on line adaptive priority strategy to optimize traffic operation at a series of consecutive grade crossings in urban areas. The proposed strategy takes into account the impact on cross-street traffic as well. A mathematical model of non linear programming with linear constraints is formulated to minimize overall passenger delays at grade crossings for light rail transit and to minimize the impact on cross-street traffic. The opti- mization is enabled by real-time arrival-time prediction with GPS-equipped vehicles. To exhibit the anticipatory performance of the proposed strategy, both a numerical analysis and a simulation test are conducted with trolley operation along a stretch of C Street in San Diego. Compared with current signal timings, those obtained from the proposed strategy demonstrate promising results. DOI: 10.1061/ (ASCE)TE.1943-5436.0000344. © 2012 American Society of Civil Engineers. CE Database subject headings: Light rail transit; Urban areas; Railroad grade crossings; Computer programming; Traffic signals; Optimization.

Pedestrian and Bicyclist Violations at Highway–Rail Grade Crossings

Each year numerous pedestrian and bicyclist crashes involving high injury levels are reported at highway–rail grade crossings (HRGCs) across the United States. Such crashes are invariably the result of errors on the part of the pedestrians and bicyclists. The focus of this paper is to investigate pedestrian and bicyclist violations at a dual-quadrant gated HRGC and to report on four types of gate violations, including factors associated with those violations. For both pedestrians and bicyclists, the violations studied were (a) passing under descending gates, (b) passing around fully lowered gates, (c) passing under ascending gates, and (d) passing around fully lowered gates between successive trains. Data on pedestrian and bicyclist violations were collected at a grade crossing in Nebraska through the use of video surveillance. Analysis indicated that there were no significant differences in the mean frequencies of pedestrian and bicyclist violations at HRGCs. When data for pedestrians and bicyclists were pooled, 1.27 gate-related violations were recorded per crossing event. Children of around 8 years of age or younger were involved in 25% more gate-related violations than older crossing users (pedestrians and bicyclists). Violations increased with the presence of more individuals at the crossing during train crossing events, but the contribution from young children was greater than that from older crossing users. The implications of the findings for HRGC safety are discussed.

Train–Vehicle Crash Risk Comparison Between Before and After Stop Signs Installed at Highway–Rail Grade Crossings

Objective: The safety benefit of stop sign treatment employed at passive highway–rail crossings has been a subject of research for many years. The objectives of this research is to investigate whether and to what degree the crash rate has changed at previously passive grade crossings after stop signs were implemented and examine whether and how the crash characteristics (associated with vehicle type, crossing surrounding, crossing design, crash severity, etc.) changed subsequently. Methods: Federal Railroad Administration grade crossing databases during the 26-year period (1980–2005) were applied in this study. Among the stop-controlled grade crossings, a total of 7394 “target” crossings were identified to be once crossbucks controlled and subsequently upgraded with the installation of stop signs without the implementation of other traffic control devices during the study period. Each target crossing was further divided into two time periods: when it was controlled by crossbucks only (before) and when it was controlled by stop signs (after). Both annual crash rate analysis and crash propensity analysis of before–after stop sign installation are conducted to quantify the safety benefit of stop sign treatment. Results: It was found that during the 26-year period (1980–2005), the annual crash rates when the crossings were controlled by crossbucks-only were consistently higher than the crash rates when the crossings were controlled by stop signs. The further crash propensity analysis indicated that the stop sign treatment was especially effective at crossings with higher annual average daily traffic (AADT), advanced warning signs, sight distance problem, adverse lighting conditions; the motorist-stopped-on-crossing, did-not-stop, and injury crash risks were also significantly reduced after stop signs were applied. Conclusions: The finding of this study suggested that the vehicle volume should be included into the guideline for stop sign use. Therefore, engineers and decision makers are encouraged to routinely check available sight distances at passive crossings controlled by crossbucks only and add stop signs to the crossings with insufficient sight distances. Additionally, it is suggested that advanced warning signs should be jointly used at stop-controlled crossings to maximize the safety effect. However, stop signs were less effective at crossings with higher train speeds or track classifications, where active warning devices may be a better safety solution for grade crossings.

Developing a basis for efficient railroad horn testing.

In response to complaints of excess noise from residents living in the vicinity of rail grade crossings, the Federal Railroad Administration promulgated regulations mandating minimum and maximum horn sound output levels. Older fleets require testing of horns to ensure compliance with these limits. Test requirements (no reflecting surfaces within 200 ft of the horn; wind less than or equal to 12 m/ph; no precipitation) severely limit the ability of urban commuter railroads to comply with the testing, especially in northern and coastal areas. To develop an alternate test protocol, measurements of horn sound levels were carried out in a semi‐anechoic chamber and outdoors to determine if a reliable transfer function could be constructed to convert the chamber measurements to the outdoor measurements. Standard deviations of the A‐weighted chamber measurements were smaller than standard deviations of the outdoor measurements. For one fleet, the differences between chamber measurements and outdoor measurements resulted in a consistent difference of about 41 dB(A). Locomotive supply air pressure differences at the horn were not a significant factor in sound output.

Quantifying the Public Impacts of Highway–Rail Grade Crossings on Surface Mobility: Regional Impact Model

This research developed a model to evaluate the impacts associated with delayed vehicular traffic at highway–rail grade crossings in the eight-county area surrounding Houston, Texas. Vehicle traffic data, such as average daily traffic and distributions by roadway class and hour of day, were obtained from state and local agencies. Data from the operating railroads were used to determine train operating levels on an hourly basis for each rail corridor. Grade crossing data and unit costs were obtained from public sources. The developed model calculated the quantitative and monetary costs of mobility, fuel consumption, safety, and air quality impacts associated with vehicular impedance at rail grade crossings. It defined the existing (baseline) mobility constraints associated with train operations in the study region and provided a method to compare the impacts of potential infrastructure projects, changes in train operations, or both with the public benefits accruing from those changes during 10- and 20-year periods. Public benefits can reach significant levels and may take the form of a reduction in the cost burden associated with road traffic delays induced by rail operations. The model has been applied in a regional rail freight study and has the potential for application in a host of other locations; this model will allow for the evaluation of investments in rail and highway infrastructure or operations, ultimately ensuring that public benefits are commensurate with public costs.

Evaluation of Effectiveness of Stop-Sign Treatment at Highway–Railroad Grade Crossings

The safety benefit of stop-sign treatment employed at passive highway–rail crossings has been a subject of research for many years. The objective of this study is to assess the effectiveness of the stop-sign treatment on crossing safety. Using the Federal Railroad Administration database, the research focused on 26 years of vehicle–train accident history in the United States from 1980 through 2005. A before-and-after and cross-sectional statistical analysis was conducted for 7,394 public highway–railroad grade crossings that were upgraded from cross buck only to stop signs without involvement in other traffic-control devices (TCDs) or automatic countermeasures. The study found that accident rates based on annual accident frequency per 1,000 crossings were significantly higher during the period when crossings were controlled by cross bucks only than when they were controlled by stop signs. Further, this study developed negative binomial accident prediction models, respectively, for paved and unpaved highway–rail grade-crossings that include effect for stop-sign treatment. Based on specific attributes of the current crossbuck-only-controlled crossings, decision makers and traffic engineers can use the models to examine the accident risks at crossings and assess the potential effectiveness of stop-sign treatment.

Evaluation of Effectiveness of Stop Sign Treatments at Highway–Railroad Grade Crossings

The safety benefit of stop sign treatments at passive highway–rail crossings has been a subject of research for many years. The objective of this study is to assess the effectiveness of the stop sign treatment on crossing safety. Using the FRA database, the research focused on 26 years of vehicle–train accident history in the United States from 1980 through 2005. A before-and-after and cross-sectional statistical analysis was conducted for 7,394 public highway–railroad grade crossings that were upgraded from being controlled only by crossbucks to stop signs, without other traffic control devices or automatic countermeasures. The study found that accident rates based on annual accident frequency per 1,000 crossings were significantly higher during the period when crossings were controlled only by crossbucks than when they were controlled by stop signs. Further, this study developed negative binomial accident prediction models for paved and unpaved highway–rail grade crossings that included the effect of stop sign treatment. Taking account of specific attributes of crossings controlled only by crossbucks, decision makers and traffic engineers can use the models to examine the accident risks at crossings and assess the potential effectiveness of stop sign treatment.

Active Signal Priority for Light Rail Transit at Grade Crossings

The basic concept and implementation of an active priority system of light rail transit (LRT) for highway–rail grade crossings are presented. The proposed priority system consists of four major components: train detectors, train travel and dwell time predictors, priority request generator (PRG), and traffic signal controllers. As the brain of the system, the PRG adopts a three-scheme conditional priority control strategy. Scheme I, which applies to late LRT trains, features a timing optimization model. The objective of this optimization model is to minimize intersection delays for late trains and meanwhile to minimize impacts on other traffic. Unlike existing signal priority studies, which typically focus on isolated intersections, the proposed model deals with signal timings at multiple intersections and provides an optimized green band for an incoming train. The optimized green band would start at the right time to cover the predicted train arrival time and would be wide enough to accommodate prediction errors. A case study, based on the San Diego Trolley system, in California, demonstrates enormous intersection delay savings of 89.5% and 25.3 s/train for late trains after application of the proposed Scheme I strategy. At the same time, the impact on other traffic in the priority cycle is only 4.1 s/veh. For Schemes II and III when no priority is needed, traffic delay savings are 32.5% and 52.0%, respectively. A simulation study confirms the system benefits and validates the practicality of the active priority system for future field testing.

Laboratory Evaluation of Intrusion Detection Technologies for High-Speed Rail Grade Crossings

The rail industry is in the process of developing a prototype system for high-speed rail. One of the concerns associated with high-speed rail is the danger posed by obstructions on the track. This level of danger is much higher than with traditional railway vehicles because the highspeed passenger equipment is both lighter and faster moving than traditional equipment. Therefore, it is more vulnerable to serious damage and derailment by objects on the track. Two existing traffic monitoring technologies were considered to have potential for railway intrusion detection: video systems and microwave systems. Qualitative laboratory tests were conducted on each system to evaluate the ability to detect objects as a function of size, material, color, and entry direction. Quantitative tests were conducted to define the capability of each type of system to detect objects as a function of object size. Test results indicate that both systems have good potential for use in railroad intrusion detection. The video system was tested in indirect natural light, medium-intensity artificial lighting, and low-level artificial lighting. Object detection was independent of color, composition, and direction of entry but was a direct function of detection zone size. Spheres as small as 4 in. in diameter were detected consistently. The microwave system would consistently detect 4-in. spheres, and results were independent of material, color, entry direction, and zone size. It was concluded that existing video- and microwave-based traffic monitoring systems have potential for use in a railroad intrusion detection application and that field tests should be pursued.

Photo Enforcement at Highway–Rail Grade Crossings in the United States: July 2000–July 2001

Nearly 50% of U.S. highway–rail crossing accidents occur at public crossings equipped with automated warning devices, of which 78% are passive and 22% have active warning systems. This is a disproportionate amount of accidents occurring at active sites. The use of photo enforcement at public highway–rail grade crossings became a focal point for study. This technology observes and records driver and pedestrian behavior, as driver behavior is at the root of the crossing safety problem. Judicial concerns and public perception and support levels are also issues of concern. Photo enforcement is an option to assist law enforcement to increase safety at public crossings. While some privacy issues remain, this system can be a reliable, cost-effective way to discourage unsafe driver behavior. Today, 75 countries use traffic cameras. Internationally, photo enforcement has been in use for more than 20 years. Experience has shown that visible, high-profile law-enforcement programs like photo enforcement reduce the number of highway–rail crossing violations. Photo enforcement at six highway–rail crossings across the United States showed positive results in reducing violations. The results of investigations at the six sites indicated a reduction of violations in the range of 34% to 92%. Implementing the technology to detect a violator is one aspect of reducing violations; persuading police and civil officials to adapt enforcement programs is another.

Supervised Interconnection Circuits at Highway–Rail Grade Crossings

After the tragic 1995 collision between a school bus and a commuter train outside of Chicago, Illinois, much attention has been given to the subject of highway-rail grade crossing safety. The 1988 edition of the Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) addresses traffic signal preemption for intersections near grade crossings as well as the electrical circuit or “interconnection” that makes traffic signal preemption possible. The objective of this study is to examine the basic interconnection circuit, as defined in the MUTCD, and explore some of its limitations. Possible improvements to the basic interconnection circuit are presented and evaluated.