Warrants for Active Warning Devices at Low-Volume Highway-Rail Grade Crossings

Author(s):  
Jaya Lakshmi Kunisetty ◽  
Angela Jannini Weissmann ◽  
Jose Weissmann ◽  
Mijia Yang ◽  
Steven P. Venglar

The main objective of this research is to reduce the number of crashes between vehicles and trains at low-volume passive highway-rail at grade crossings by developing a revised safety index and warrants for active warning devices in the state of Texas. The research is focused only on low-volume crossings because most high-volume crossings in the state of Texas have already received improvements in terms of traffic control devices as the existing Texas priority index prioritizes high-volume crossings. This technical paper will describe and provide the most up-to-date preliminary results for warrants of the first year study in a two year Texas Department of Transportation (TxDOT) 0-6642 project called “Developing Warrants for Active Warning Devices at Low-Volume Highway-Rail Grade Crossings.” In order to prioritize the crossings that meet warrants a priority index should be used. The current Texas priority index places more emphasis on high-volume crossings with crash history and it doesn’t include several important variables. In order to address the issues of the current Texas priority index a new Texas Passive Crossing Index was developed based on a different concept — instead of using numeric thresholds, cumulative percentiles of the relevant variables are used.

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):  
Brian L. Bowman ◽  
Kristen Stinson ◽  
Cecil Colson

In April 1996, the state of Alabama Legislature, through the passage of Act 503, directed the Alabama Department of Transportation (ALDOT) to conduct a comprehensive study of rail-highway grade crossings in the state and recommend methods to drastically reduce the number of vehicle-train crashes. Senate Act 503 states: “… That the Alabama Department of Transportation is directed to conduct a comprehensive study of the rail/highway grade crossings in the state and present a plan to this body recommending methods to dramatically reduce vehicle/train accidents by the first day of the 1997 Regular Session.” In response to Act 503, the Multimodal Bureau of ALDOT developed an Action Plan that compared Alabama’s grade crossing crash experience with the experience of the national and southeastern states to identify the prevalent characteristics, identified the perceived needs of safety and railroad professionals required to decrease vehicle-train crashes and crash severity, and compiled a list of recommendations and activities required for implementation. The activities and results of the Act 503 study documented in the final report are summarized (1). It discusses the engineering, economic, educational, enforcement, and emotional impediments to increasing rail-highway intersection safety and presents a broad range of realistic countermeasures. These countermeasures include legislative action; judicial reform; and enforcement, economic, and education initiatives.


Author(s):  
Amy Epps Martin ◽  
Shi Chang ◽  
Swathi Mayi Theeda ◽  
Edith Arámbula-Mercado

Over the past 15 years, a surface performance-graded (SPG) specification for chip seal binders has been developed by the Texas Department of Transportation and has been validated with laboratory measurements and the visual field performance of 120 highway sections. The SPG specification was established in an effort to extend the service life of chip seals by providing a binder grading system and an associated selection method that ( a) accounted for differences in climate and ( b) used existing equipment and performance-based properties that precluded bleeding and aggregate loss in the critical first year of service after construction. A multiyear implementation effort of this specification is ongoing. This paper describes the motivation and evolution of the SPG specification, including a summary of the validation effort and a round robin testing program with the Texas Department of Transportation and suppliers of chip seal binders. Binder selection guidelines that use this specification are provided.


Author(s):  
Edmond Chin-Ping Chang

Research sponsored by the Texas Department of Transportation, Efficient Utilization of Actuated Controllers in Coordinated Traffic Control Systems, was used to develop a set of reliable control strategies to allow users to improve the overall design and operation of actuated controllers in conventional coordinated systems. The recommended analysis procedure can help users generate the signal timing parameters for coordinated arterial or network operations. Actuated, coordinated traffic signal system implementation will maximize the available resources for effective coordinated operations during undersaturated conditions, demand variations, and near-saturation conditions. The recommended coordination strategies and implementation guidelines for using actuated controllers effectively on coordinated signal systems are summarized. The study will effectively assist users in selecting the proper controller-detector combinations and improving system detector locations. It will also aid users in optimizing actuated timing parameters in actuated control operation of arterial signal systems.


Author(s):  
Roger P. Bligh ◽  
King K. Mak ◽  
Lewis R. Rhodes

Proper traffic control and delineation are critical to achieving safety in work zones. However, the work zone traffic control devices themselves may pose a safety hazard to vehicle occupants or work crews when impacted by errant vehicles. Thus, there was a need to research the safety performance of work zone traffic control devices to ensure that they perform satisfactorily and meet NCHRP Report 350 guidelines. Several research studies sponsored by the Texas Department of Transportation evaluated the impact performance of various work zone traffic control devices, such as temporary and portable sign supports, plastic drums, sign substrates for use with plastic drums, traffic cones, and vertical panels. Specifically addressed are the studies on barricades. Standard wooden barricade construction was found to be unacceptable due to a demonstrated potential for intrusion of fractured members into the occupant compartment. In response to deficiencies identified in the wooden barricade tests, several alternate barricade designs were developed and successfully tested.


2016 ◽  
Vol 82 (5) ◽  
pp. 407-411 ◽  
Author(s):  
Thomas W. Wood ◽  
Sharona B. Ross ◽  
Ty A. Bowman ◽  
Amanda Smart ◽  
Carrie E. Ryan ◽  
...  

Since the Leapfrog Group established hospital volume criteria for pancreaticoduodenectomy (PD), the importance of surgeon volume versus hospital volume in obtaining superior outcomes has been debated. This study was undertaken to determine whether low-volume surgeons attain the same outcomes after PD as high-volume surgeons at high-volume hospitals. PDs undertaken from 2010 to 2012 were obtained from the Florida Agency for Health Care Administration. High-volume hospitals were identified. Surgeon volumes within were determined; postoperative length of stay (LOS), in-hospital mortality, discharge status, and hospital charges were examined relative to surgeon volume. Six high-volume hospitals were identified. Each hospital had at least one surgeon undertaking ≥ 12 PDs per year and at least one surgeon undertaking < 12 PDs per year. Within these six hospitals, there were 10 “high-volume” surgeons undertaking 714 PDs over the three-year period (average of 24 PDs per surgeon per year), and 33 “low-volume” surgeons undertaking 225 PDs over the three-year period (average of two PDs per surgeon per year). For all surgeons, the frequency with which surgeons undertook PD did not predict LOS, in-hospital mortality, discharge status, or hospital charges. At the six high-volume hospitals examined from 2010 to 2012, low-volume surgeons undertaking PD did not have different patient outcomes from their high-volume counterparts with respect to patient LOS, in-hospital mortality, patient discharge status, or hospital charges. Although the discussion of volume for complex operations has shifted toward surgeon volume, hospital volume must remain part of the discussion as there seems to be a hospital “field effect.”


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Josephine Obel ◽  
Antonio Isidro Carrion Martin ◽  
Abdul Wasay Mullahzada ◽  
Ronald Kremer ◽  
Nanna Maaløe

Abstract Background Fragile and conflict-affected states contribute with more than 60% of the global burden of maternal mortality. There is an alarming need for research exploring maternal health service access and quality and adaptive responses during armed conflict. Taiz Houbane Maternal and Child Health Hospital in Yemen was established during the war as such adaptive response. However, as number of births vastly exceeded the facility’s pre-dimensioned capacity, a policy was implemented to restrict admissions. We here assess the restriction’s effects on the quality of intrapartum care and birth outcomes. Methods A retrospective before and after study was conducted of all women giving birth in a high-volume month pre-restriction (August 2017; n = 1034) and a low-volume month post-restriction (November 2017; n = 436). Birth outcomes were assessed for all births (mode of birth, stillbirths, intra-facility neonatal deaths, and Apgar score < 7). Quality of intrapartum care was assessed by a criterion-based audit of all caesarean sections (n = 108 and n = 82) and of 250 randomly selected vaginal births in each month. Results Background characteristics of women were comparable between the months. Rates of labour inductions and caesarean sections increased significantly in the low-volume month (14% vs. 22% (relative risk (RR) 0.62, 95% confidence interval (CI) 0.45-0.87) and 11% vs. 19% (RR 0.55, 95% CI 0.42-0.71)). No other care or birth outcome indicators were significantly different. Structural and human resources remained constant throughout, despite differences in patient volume. Conclusions Assumptions regarding quality of care in periods of high demand may be misguiding - resilience to maintain quality of care was strong. We recommend health actors to closely monitor changes in quality of care when implementing resource changes; to enable safe care during birth for as many women as possible.


Author(s):  
Miriam Lillo-Felipe ◽  
Rebecka Ahl Hulme ◽  
Maximilian Peter Forssten ◽  
Gary A. Bass ◽  
Yang Cao ◽  
...  

Abstract Background The relationship between hospital surgical volume and outcome after colorectal cancer surgery has thoroughly been studied. However, few studies have assessed hospital surgical volume and failure-to-rescue (FTR) after colon and rectal cancer surgery. The aim of the current study is to evaluate FTR following colorectal cancer surgery between clinics based on procedure volume. Methods Patients undergoing colorectal cancer surgery in Sweden from January 2015 to January 2020 were recruited through the Swedish Colorectal Cancer Registry. The primary endpoint was FTR, defined as the proportion of patients with 30-day mortality after severe postoperative complications in colorectal cancer surgery. Severe postoperative complications were defined as Clavien–Dindo ≥ 3. FTR incidence rate ratios (IRR) were calculated comparing center volume stratified in low-volume (≤ 200 cases/year) and high-volume centers (> 200 cases/year), as well as with an alternative stratification comparing low-volume (< 50 cases/year), medium-volume (50–150 cases/year) and high-volume centers (> 150 cases/year). Results A total of 23,351 patients were included in this study, of whom 2964 suffered severe postoperative complication(s). Adjusted IRR showed no significant differences between high- and low-volume centers with an IRR of 0.97 (0.75–1.26, p = 0.844) in high-volume centers in the first stratification and an IRR of 2.06 (0.80–5.31, p = 0.134) for high-volume centers and 2.15 (0.83–5.56, p = 0.116) for medium-volume centers in the second stratification. Conclusion This nationwide retrospectively analyzed cohort study fails to demonstrate a significant association between hospital surgical volume and FTR after colorectal cancer surgery. Future studies should explore alternative characteristics and their correlation with FTR to identify possible interventions for the improvement of quality of care after colorectal cancer surgery.


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