UNT Libraries Government Documents Department - 87 Matching Results

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Implementation of Transverse Variable Asphalt Rate seal coat practices in Texas

Description: An implementation project was performed to expand use of transversely varied asphalt rate (TVAR) seal coat practices in all districts. The project included nine regional workshops, continued field texture testing of test sites, provided one set of sand patch test equipment to each Texas Department of Transportation (TxDOT) district, and published 500 copies of the TVAR Field Guide for broad TxDOT distribution.
Date: January 2011
Creator: Krugler, Paul E. & Estakhri, Cindy K.

Improving stop line detection using video imaging detectors

Description: "The Texas Department of Transportation and other state departments of transportation as well as cities nationwide are using video detection successfully at signalized intersections. However, operational issues with video imaging vehicle detection systems (VIVDS) products occur at some locations. The resulting issues vary but have included: camera contrast loss resulting in max-recall operation, failure to detect vehicles leading to excessive delay and red-light violations, and degraded detection accuracy during nighttime hours. This research resulted in the development of a formalized VIVDS test protocol and a set of performance measures that agencies can incorporate in future purchase orders and use to uniformly evaluate VIVDS products. It also resulted in the development of a VIVDS video library and conceptual plans for a field laboratory for future projects to deploy a range of VIVDS products at an operational signalized intersection. Researchers evaluated alternative VIVDS stop line detection designs and developed methods for enhancing the operation of VIVDS through adjustments in controller settings for day versus night versus transition periods, zone placement, and camera placement."
Date: August 2009
Creator: Middleton, Daniel R.; Longmire, Ryan; Charar, Hassan; Bullock, Darcy & Bonneson, James A.

Internal trip capture estimator for mixed-use developments

Description: This report describes a spreadsheet tool for estimating trip generation for mixed-use developments, accounting for internal trip capture. Internal trip capture is the portion of trips generated by a mixed-use development that both begin and end within the development. The importance of internal trip capture is that those trips satisfy a portion of the total development's trip generation and they do so without using the external road system. As a result, a mixed-use development that generates a given number of total trips creates less demand on the external road system than single-use developments generating the same number of trips. This report describes the spreadsheet estimator and how to use it. It describes the data behind the estimator as well as how those data are applied. The two Texas mixed-use developments from which most of the data were derived are also described. This report is supplemented by the Excel® spreadsheet itself as well as task memoranda that document the survey data collected as part of this project.
Date: February 2010
Creator: Bochner, Brian S. & Sperry, Benjamin R.

Laboratory and field performance measurements to support the implementation of warm mix asphalt in Texas

Description: An objective of this study was to monitor the performance of more than 10 warm mix asphalt (WMA) projects in the state. Several WMA technologies were included in the study (foaming, Advera, Evotherm, Rediset, Sasobit) and it was determined that performance of the warm mix was comparable to hot mix. In addition, mix from two warm mix projects were subjected to different curing times and temperatures and then evaluated for mixture volumetrics and performance properties. Results from this study lend support to the current procedures the Texas Department of Transportation has adopted.
Date: July 2012
Creator: Estakhri, Cindy K.

Landside freight access to airports : findings and case studies

Description: "Texas' airports play a large role in the national and regional movement of goods by air. This includes goods moved within the state, across the country, and internationally to several continents. Most of this movement of goods is accomplished at the largest airports in Texas. However, as freight demand grows, a time will come when other airports will need to be utilized to accommodate additional demand. Properly planned transportation infrastructure is critical to ensure the vitality of an airport's freight operations. Time-sensitive air freight requires high levels of operational efficiency, which is generally optimized by taking steps to ensure both freight and passenger roadway access within the airport boundaries. Connections and design features of regional highways near the airports are no less important because they allow access to these important economic generators. This research report identifies the issues, barriers, physical bottlenecks (e.g., infrastructure needs), and solutions (including funding mechanisms) concerning landside access to airports in Texas. Inner city airports in large metropolitan areas sometimes face roadway geometric challenges, but typically have relatively low cargo activity levels. Shipping representatives stated that wayfinding is a key characteristic in providing good landside freight access to airports. Signage needs to be visible and informative in advance of necessary turns or lane changes. Efforts need to be taken to minimize comingling of freight and passenger traffic in areas near the passenger terminals. A variety of funding opportunities exist through public, private, and shared sources to improve access to airports."
Date: August 2010
Creator: Frawley, William E.; Borowiec, Jefferey D.; Protopapa, Annie A.; Morgan, Curtis Alan & Warner, Jeffery E.

Manual for Assessing Safety Hardware test 3-10 on 31-inch W-beam guardrail with standard offset blocks

Description: "The test reported herein corresponds to American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) test 3-10. This is primarily a severity test that assesses risk of injury to the vehicle occupants."
Date: November 2010
Creator: Abu-Odeh, Akram Y.; Menges, Wanda L. & Bligh, Roger P.

Manual for Assessing Safety Hardware test 3-11 of the Texas Department of Transportation Portable Concrete Traffic Barriers with sign support assembly

Description: This report presents the details of the design developed for mounting the traffic control sign support on top a portable concrete traffic barrier (PCTB), description of the full scale crash test performed on the design, and an assessment and evaluation of the performance of the PCTB with the sign support mounted on top according to specifications of "Manual for Assessing Safety Hardware" (MASH). The PCTB mounted sign support assembly anchored to the top of the TxDOT Type 2 PCTB tested for this project performed acceptably for MASH test 3-11.
Date: January 2011
Creator: Williams, William F. & Menges, Wanda L.

Manual for Assessing Safety Hardware test 3-11 on the Texas T101 bridge rail

Description: The Texas T101 bridge rail is widely used in the state of Texas. Previous testing demonstrated its ability to contain and redirect passenger cars and a 20,000-lb school bus. Based on this testing, the Federal Highway Administration accepted the T101 bridge rail as an NCHRP Report 350 TL-3 barrier. However, its impact performance with pickup trucks was never evaluated. Under research project 0-5526, Impact Performance of Roadside Safety Appurtenances, researchers conducted a performance assessment of Texas roadside safety devices to help evaluate the impact of adopting the new AASHTO Manual for Assessing Safety Hardware (MASH) guidelines on current hardware. Testing and evaluation of the T101 bridge rail was recommended as a high priority. This recommendation was based primarily on the absence of pickup truck testing on the system, and concerns that the 27-inch rail height may not be compatible with pickup trucks and SUVs under design impact conditions. The T101 bridge rail did not meet MASH evaluation criteria for test 3-11. The vehicle overturned after losing contact with the barrier.
Date: March 2011
Creator: Bligh, Roger P. & Menges, Wanda L.

MASH test 3-37 of the TxDOT 31-inch w-beam downstream anchor terminal

Description: Report discussing the findings of a study into issues related to roadside safety devices: "The objective of this study was to develop a suitable replacement for the downstream 'turn-down' guardrail anchor system. The 'turn-down' guardrail anchor system does not meet mandated test requirements under MASH for upstream anchor application terminals; however, it does meet downstream requirements for previous crash testing standard" (abstract). It includes background information, system details, test requirements and evaluation criteria, crash test procedures, crash test results, and conclusions.
Date: October 2011
Creator: Bligh, Roger P.; Menges, Wanda L. & Arrington, Dusty R.

Microsurfacing in Texas

Description: This report describes the current state of practice of microsurfacing in Texas and compares it to best practices extracted from existing literature. A survey of DOT personnel, contractors and emulsion suppliers in Texas provides insight into the most crucial factors contributing to the success or failure of a microsurfacing. From the results of the survey, literature reviews, case studies and site visits, the research team analyzed material selection and mix design methods, construction practices, equipment practices and performance measures for microsurfacings.
Date: August 2011
Creator: Broughton, Benjamin & Lee, Soon-Jae

Mobility and economic effects of system investments in Texas: 2010 to 2020

Description: "The report summarizes estimates of the consequences of current funding levels and a range of greater and lesser funding amounts. The report describes the population, travel, system extent and expenditure data and analyses used to develop the mobility and economic effect analyses. An associated study by the Center for Transportation Research analyzed pavement maintenance spending and condition. Both the mobility and pavement studies were used as part of the March 2011 Texas 2030 Committee report."
Date: August 2011
Creator: Lomaz, Tim

Modern traffic control devices to improve safety at rural intersections

Description: "The goal of this project was to obtain a better understanding of modern TCD capabilities. Researchers conducted the following tasks literature review, crash data examination, TxDOT district survey, laboratory survey, field study, and development of principles for selecting TCDs."
Date: September 2011
Creator: Fitzpatrick, Kay; Chrysler, Susan T.; Sunkari, Srivivasa R.; Cooper, Joel; Park, Byung-Jung & Higgins, Laura

Non-vital advance rail preemption of signalized intersections near highway-rail grade crossings

Description: The Texas Department of Transportation (TxDOT) primarily uses simultaneous preemption of traffic signals near highway-rail grade crossings to clear queued vehicles prior to the arrival of a train at the crossing. At some intersections, 20 seconds of advanced warning may not be sufficient to allow the traffic signal to clear pedestrians using the normal clearance intervals between phases. The research developed an alternative method (non-vital advance preemption) of ensuring adequate pedestrian clearance in the presence of an approaching train without interfering with the normal preemption sequence at the intersection or installing costly additional track circuitry needed to provide advance preemption. Two strategies were investigated to ensure pedestrian clearance time. The first utilizes a lower-level preemption sequence to guarantee full pedestrian clearance to a terminating phase before the traffic signal starts the preemption sequence. The second strategy uses the pedestrian-omit feature to prevent the controller from activating the pedestrian interval if there is not sufficient time in advance of the start of the preemption sequence to provide full pedestrian clearance.
Date: June 2007
Creator: Balke, Kevin N.; Engelbrecht, Roelof Johannes & Ruback, Leonard G.

Operational Performance Management of Priced Facilities

Description: This study provides a framework in which operating decisions for priced facilities can be made and can guide the changes in operational strategies for a facility over time. The research process was initiated with a literature review and targeted interviews of toll and managed lane operators to assess the state of the practice in performance measurement for pricing and other operational changes. The research team then developed guiding principles for identification, selection, and communication of performance measures and targets. A conceptual framework was formulated and data collection infrastructure needs were also documented. The conceptual framework was then developed into a more detailed version in a web-based format. This report documents the research findings and results and provides guidance on the use of the web-based framework tool. In addition, several outreach products were developed under this study to assist agencies in communication of performance management principles for proactive management of priced facilities.
Date: March 2011
Creator: Goodin, Ginger; Burris, Mark; Lomax, Timothy J.; Geiselbrecht, Tina & Brydia, Robert

The Overlay Tester : A Sensitivity Study to Improve Repeatability and Minimize Variability in the Test Results

Description: "This report presents a comprehensive sensitivity evaluation of the critical steps of the Overlay Tester (OT) test procedure in an attempt to optimize the OT repeatability and minimize variability in the test results."
Date: February 2012
Creator: Walubita, Lubinda F.; Faruk, Abu N.; Das, Gautam; Tanvir, Hossain A.; Zhang, Jun & Scullion, Tom

Peer grouping and performance measurement to improve rural and urban transit in Texas

Description: "Rural and small urban transit systems in Texas will become even more important with predicted changes in population trends. Rural demographic trends indicate growth in the number of persons age 65 and over coupled with a decrease in population density. Small urban area trends indicate substantial population growth and broadened geographic boundaries, yet resources to provide rural and small urban transit are limited. Therefore, transit managers find it is increasingly important to maximize service efficiency and effectiveness. The purpose of this research was to identify peer groups, performance benchmarks, and strategies used by successful transit providers to achieve high performance. The research project identifies peer groups based on the transit environment within which each agency operates, so that agencies can be compared to other operators who face similar environments. Peer group effectiveness and efficiency performance are examined within and between rural and urban peer groups, and high performers are identified for case studies. Through the case studies, key attributes are identified for achieving high operating efficiency and/or effectiveness. Performance strategies are categorized to provide transit providers with transferrable information to improve performance and increase the return on transit investment."
Date: September 2010
Creator: Arndt, Jeffrey C.; Edrington, Suzie; Sandidge, Matthew; Quadrifoglio, Luca & Perkins, Judy

Performance comparison of various seal coat grades used in Texas

Description: This report documents research efforts to provide comparative quantitative performance information for various grades of seal coat aggregate available in the Texas Department of Transportation standard specifications. Length of service before replacement and level of noise generated at the tire-pavement interface were the primary focuses of the relative performance evaluations. The additional service life possible from seal coats with larger aggregate and higher asphalt application rates is compared to the additional cost generally associated with these larger aggregate seal coats. The comparative performance information combined with knowledge gathered from numerous department field engineers resulted in the development of guidelines for optimal seal coat grade selection.
Date: July 2012
Creator: Krugler, Paul E.; Wirth, John E.; Estakhri, Cindy K.; Freeman, Thomas J.; Wikander, John P. & Wimsatt, Andrew J.

Performance Measures for Public Transit Mobility Management

Description: Report that looks at the state of mobility management practice throughout Texas, as well as national best practices in mobility management. Additionally, this research provides an overview of the varying roles of state departments of transportation in public transit mobility management efforts. The research also presents applied mobility management for agencies seeking to implement mobility management programs as well as a menu of performance measures that can be utilized based on the type and level of program implemented.
Date: December 2011
Creator: Sen, Lalita; Majumdar, Sarmistha R.; Highsmith, Meredith; Cherrington, Linda K. & Gilliland, Cynthia A. Weatherby

Performance monitoring pavements with thermal segregation in Texas

Description: This report investigated the performance of asphalt surface mixtures that exhibited thermal segregation during construction from 2004 to 2009. The results do not show that thermally segregated locations will fail within three to seven years but they do show that instances of thermal segregation may continue to be anomalous locations in the layer that could lead to failures in the pavement structure.
Date: April 2012
Creator: Sebesta, Stephen & Scullion, Tom

Planning tools to assess the real estate leveraging potential for roadways and transit: technical report

Description: A funding crisis exists for financing much needed transportation infrastructure projects across the nation and Texas is no exception. Texas has responded to the crisis by passing several bills allowing innovative financing and alternative options for project financing. Among these is Senate Bill 1266 (SB1266), which is a landmark legislation and was passed in 2007 as part of the 80th Legislature to provide the legal backdrop for the creation of the Transportation Reinvestment Zone (TRZ) to facilitate value capture of the tax increment from a future transportation project. This research aimed to provide various mechanisms to augment the implementation and understanding of SB1266 provisions across the state of Texas including but not limited to documenting the current understanding and knowledge of the legislative provisions, compilation of actual implementation case examples, development of standardized methods for screening, TRZ development and revenue assessments, and also presents the results of a workshop held to augment the understanding of TRZ for highway projects. An additional section of this research explores the implications of SB1266 for transit finance and discusses this aspect within the larger context for innovative finance of all transit infrastructure both those on the state highway systems and off. Finally, specific recommendations to the legal framework are made in the light of specific objectives of the research both for highways and transit in regard to the use of increment based finance.
Date: January 2011
Creator: Vadali, Sharada; Bujanda, Arturo; Li, Yingfeng; Kuhn, Beverly; Zhang, Ming; Aldrete, Rafael M. et al.