Preliminary Analysis of Light Rail Crashes in Denver, Colorado

Author(s):  
Pamela M. Fischhaber ◽  
Bruce N. Janson

This paper presents a preliminary analysis of light rail crashes at at-grade crossings in Denver, Colorado, based on Regional Transportation District data for 1999 through 2009. Differences in design and operation of at-grade crossings are discussed for light rail versus common carrier railroad (railroad). The differences appear to warrant the development of separate crash prediction and hazard index models because models developed for railroad at-grade crossing operations may not accurately predict the number and severity of crashes at light rail at-grade crossings. In addition, the models developed for railroads do not predict crashes at crossings for some traffic control device types such as traffic signals. The lack of information for crossings controlled by traffic signals in the railroad crash prediction equations is one reason why equations specific to light rail may need to be developed. This study identifies patterns in light rail crossing crash data that warrant further investigation and support the development of crash prediction models and hazard index equations specific to light rail at-grade crossing configurations and operations.

2020 ◽  
Vol 12 (10) ◽  
pp. 4291 ◽  
Author(s):  
Junayed Pasha ◽  
Maxim A. Dulebenets ◽  
Olumide F. Abioye ◽  
Masoud Kavoosi ◽  
Ren Moses ◽  
...  

Accidents at highway-rail grade crossings can cause fatalities and injuries, as well as significant property damages. In order to prevent accidents, certain upgrades need to be made at highway-rail grade crossings. However, due to limited monetary resources, only the most hazardous highway-rail grade crossings should receive a priority for upgrading. Hence, accident/hazard prediction models are required to identify the most hazardous highway-rail grade crossings for safety improvement projects. This study selects and evaluates the accident and hazard prediction models found in the highway-rail grade crossing safety literature to rank the highway-rail grade crossings in the State of Florida. Three approaches are undertaken to evaluate the candidate accident and hazard prediction models, including the chi-square statistic, grouping of crossings based on the actual accident data, and Spearman rank correlation coefficient. The analysis was conducted for the 589 highway-rail grade crossings located in the State of Florida using the data available through the highway-rail grade crossing inventory database maintained by the Federal Railroad Administration. As a result of the performed analysis, a new hazard prediction model, named as the Florida Priority Index Formula, is recommended to rank/prioritize the highway-rail grade crossings in the State of Florida. The Florida Priority Index Formula provides a more accurate ranking of highway-rail grade crossings as compared to the alternative methods. The Florida Priority Index Formula assesses the potential hazard of a given highway-rail grade crossing based on the average daily traffic volume, average daily train volume, train speed, existing traffic control devices, accident history, and crossing upgrade records.


Author(s):  
Darren J. Torbic ◽  
Daniel Cook ◽  
Joseph Grotheer ◽  
Richard Porter ◽  
Jeffrey Gooch ◽  
...  

The objective of this research was to develop new intersection crash prediction models for consideration in the second edition of the Highway Safety Manual (HSM), consistent with existing methods in HSM Part C and comprehensive in their ability to address a wide range of intersection configurations and traffic control types in rural and urban areas. The focus of the research was on developing safety performance functions (SPFs) for intersection configurations and traffic control types not currently addressed in HSM Part C. SPFs were developed for the following general intersection configurations and traffic control types: rural and urban all-way stop-controlled intersections; rural three-leg intersections with signal control; intersections on high-speed urban and suburban arterials (i.e., arterials with speed limits greater than or equal to 50 mph); urban five-leg intersections with signal control; three-leg intersections where the through movements make turning maneuvers at the intersections; crossroad ramp terminals at single-point diamond interchanges; and crossroad ramp terminals at tight diamond interchanges. Development of severity distribution functions (SDFs) for use in combination with SPFs to estimate crash severity as a function of geometric design elements and traffic control features was explored; but owing to challenges and inconsistencies in developing and interpreting the SDFs, it was recommended for the second edition of the HSM that crash severity for the new intersection configurations and traffic control types be addressed in a manner consistent with existing methods in Chapters 10, 11, and 12 of the first edition, without use of SDFs.


2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Jingsi Yang ◽  
Xuedong Yan ◽  
Qingwan Xue ◽  
Xiaomeng Li ◽  
Ke Duan ◽  
...  

The complex environment at grade crossings and the severe collision consequences give rise to the concern of safety condition at crossings among traffic control authorities. Optimizing conventional devices and applying emerging technologies are worthwhile measures to improve the safety conditions at grade crossings. In this study, a flashing-light running (FLR) warning system was proposed to reduce crossing violation and improve performances of drivers at flashing-light-controlled grade crossings (FLCGCs). Forty-four fully licensed drivers aged between 30 and 48 years participated in a driving simulator study to investigate the efficacy of two countermeasures of the system: proposed design of signs and pavement markings (PSM) for grade crossing, and two-stage in-vehicle audio warning (IVAW) technology. A range of flashing light trigger timing and two foggy conditions were designed in this experiment to test the system applicability. Drivers’ gender and vocation were considered as well to examine drivers’ adaptation to the new proposed system. Five variables were collected and analyzed in this study to investigate the effectiveness of the system, i.e., drivers’ compliance, approaching mean speed, brake reaction time, deceleration, and red-to-crossing time. Results showed that drivers’ driving performances were improved in both PSM only condition and PSM + W condition. The FLR warning system could eliminate the negative effects of foggy weather and reduce gender differences in driver behaviors to some extent. These findings suggested that the FLR warning system has a potential to reduce the probability of grade crossing collisions.


Author(s):  
Yifeng Chen ◽  
Laurence R. Rilett

Traffic signal optimization for traffic signals located near highway-rail grade crossings (HRGC) can be difficult because of the complex nature of the interactions between the two systems and the necessity of considering multiple objectives, such as safety and operational efficiency. The problems are magnified when considering traffic control for corridors that have multiple intersections located near HRGCs. This paper develops a methodology for optimizing traffic signals along a highway-railway corridor while considering the dual objectives of maximizing safety and efficiency. The Highway 6 (Cornhusker Hwy) corridor in Lincoln, Nebraska was used as a test bed. The corridor was modeled in VISSIM, and was used to emulate the traffic control along Highway 6, including the preemption logic. The traffic control logic was modeled using the Vehicle Actuated Programming (VAP) in the VISSIM simulation model. In addition, the logic allows multiple train events on the railway track that runs parallel to Highway 6 to be modeled. The model was calibrated to local traffic conditions using empirical field data. The impact of train frequency, length, direction, speed, etc., on the performance of the network and pedestrian safety will be evaluated.


Author(s):  
David A. Noyce ◽  
Daniel B. Fambro

More than 2,000 crashes and 239 fatalities were reported at public passive highway-railroad grade crossings in 1994. Driver error, often due to a breakdown in communication between traffic control devices and the driver, is commonly cited as a factor in passive grade crossing crashes. The objective of this study was to evaluate an improved method for communicating with drivers in an effort to improve safety at passive grade crossings. Specifically, this study evaluated the effectiveness of a vehicle-activated strobe light and supplemental sign as enhancements to the railroad advance (W10-1) warning sign at a passive highway-railroad grade crossing near Temple, Texas. Three study methods were used to evaluate this enhanced sign system including a before and after speed study, a driver survey, and a driver observation study. The results indicated that average speeds on the approaches to the grade crossing were lower after the installation of the enhanced sign system. Drivers responded favorably to the enhanced sign system, and no adverse driver reactions were observed at the onset of the flashing strobe light. The strobe light was effective in directing drivers’ attention to the railroad advance warning and supplemental signs. The enhanced sign system appears to increase driver awareness of the passive grade crossing, cause some drivers to approach the grade crossing with additional caution, and reduce the average speed near the nonrecovery zone on both approaches.


Author(s):  
Laurence R. Rilett ◽  
Justice Appiah

This paper examines the usefulness of supplementing railroad preemption operations at highway-rail grade crossings with variable message signs. Using the microscopic traffic simulation model, VISSIM, the effects on grade crossing operations of different train dwell times as well as different levels of driver response to a variable message sign in the vicinity of the crossing are assessed. The results affirm the potential usefulness of variable message signs for preventing lengthy queues and illustrate the importance of explicitly considering the delay experienced by vehicles on the blocked roadway in developing a traffic control strategy for highway-rail grade crossings.


2020 ◽  
Vol 28 (3) ◽  
pp. 251-274
Author(s):  
Olumide F. Abioye ◽  
Maxim A. Dulebenets ◽  
Junayed Pasha ◽  
Masoud Kavoosi ◽  
Ren Moses ◽  
...  

Abstract Highway–rail grade crossings (HRGCs) are one of the most dangerous segments of the transportation network. Every year numerous accidents are recorded at HRGCs between highway users and trains, between highway users and traffic control devices, and solely between highway users. These accidents cause fatalities, severe injuries, property damage, and release of hazardous materials. Researchers and state Departments of Transportation (DOTs) have addressed safety concerns at HRGCs in the USA by investigating the factors that may cause accidents at HRGCs and developed certain accident and hazard prediction models to forecast the occurrence of accidents and crossing vulnerability. The accident and hazard prediction models are used to identify the most hazardous HRGCs that require safety improvements. This study provides an extensive review of the state-of-the-practice to identify the existing accident and hazard prediction formulae that have been used over the years by different state DOTs. Furthermore, this study analyzes the common factors that have been considered in the existing accident and hazard prediction formulae. The reported performance and implementation challenges of the identified accident and hazard prediction formulae are discussed in this study as well. Based on the review results, the US DOT Accident Prediction Formula was found to be the most commonly used formula due to its accuracy in predicting the number of accidents at HRGCs. However, certain states still prefer customized models due to some practical considerations. Data availability and data accuracy were identified as some of the key model implementation challenges in many states across the country.


2021 ◽  
Vol 13 (16) ◽  
pp. 9011
Author(s):  
Nopadon Kronprasert ◽  
Katesirint Boontan ◽  
Patipat Kanha

The number of road crashes continues to rise significantly in Thailand. Curve segments on two-lane rural roads are among the most hazardous locations which lead to road crashes and tremendous economic losses; therefore, a detailed examination of its risk is required. This study aims to develop crash prediction models using Safety Performance Functions (SPFs) as a tool to identify the relationship among road alignment, road geometric and traffic conditions, and crash frequency for two-lane rural horizontal curve segments. Relevant data associated with 86,599 curve segments on two-lane rural road networks in Thailand were collected including road alignment data from a GPS vehicle tracking technology, road attribute data from rural road asset databases, and historical crash data from crash reports. Safety Performance Functions (SPFs) for horizontal curve segments were developed, using Poisson regression, negative binomial regression, and calibrated Highway Safety Manual models. The results showed that the most significant parameter affecting crash frequency is lane width, followed by curve length, traffic volume, curve radius, and types of curves (i.e., circular curves, compound curves, reverse curves, and broken-back curves). Comparing among crash prediction models developed, the calibrated Highway Safety Manual SPF outperforms the others in prediction accuracy.


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