UNT Libraries Government Documents Department - 87 Matching Results

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Development of Texas Transportation Institute's asphalt compaction monitoring system

Description: "In recent years, the Texas Department of Transportation has made significant progress with the development and implementation of new technologies to measure the uniformity of new hot mix asphalt layer construction. In Project 0-6992, researchers took this check one step further by developing an accurate global positioning system tracking system for compaction rolling so that the compaction effort applied can be monitored for 100 percent of the new surface. This report presents details of the hardware and software developed in this study. The system was field tested on a number of new overlay projects in Texas."
Date: July 2012
Creator: Liu, Wenting; Scullion, Thomas & Kassem, Emad

Realtime monitoring of bridge scour using remote monitoring technology

Description: The research performed in this project focuses on the application of instruments including accelerometers and tiltmeters to monitor bridge scour. First, two large scale laboratory experiments were performed. One experiment is the simulation of a bridge with a shallow foundation, and the other is the simulation of a bridge with a deep foundation. A series of instruments were installed on the simulated bridge to monitor the performance of the bridge due to scour. Both the shallow foundation experiment and deep foundation experiment show that accelerometers and tiltmeters can be used in scour monitoring events since both give warning of bridge failure successfully. Subsequently, two individual monitoring systems were designed and installed on two bridges: US59 over Guadalupe River Bridge and SH80 over San Antonio River Bridge in Texas. Realtime data are collected and transmitted to a computer server at Texas A&M University, which can be accessed remotely. The instrumentation on the two bridges does not show great hope of application of accelerometers to monitor bridge scour because of a lack of sufficient excitation from traffic. Another issue with the accelerometers is the high power consumption during the transmission of accelerometer data, which cannot be satisfied with a typical solar panel and battery. Tiltmeters can provide the integral behavior of the bridge, and therefore are very useful devices for scour monitoring. Guidelines and protocols for scour monitoring based on the US59 over Guadalupe River Bridge and the SH80 over San Antonio River Bridge are provided in the study.
Date: February 2011
Creator: Briaud, Jean-Louis; Hurlebaus, Stefan; Chang, Kuang-An; Yao, Congpu; Sharma, Hrishikesh; Yu, Ok-Youn et al.

Research and recommendations for a statewide sign retroreflectivity maintenance program

Description: "This report evaluated Texas Department of Transportation's (TxDOT) current sign retroreflectivity maintenance practices, assessed their effectiveness, and recommended statewide sign retroreflectivity maintenance practices that could be easily and effectively implemented to ensure that TxDOT would be in compliance with the new Manual on Uniform Traffic Control Devices (MUTCD) language related to minimum sign retroreflectivity."
Date: April 2012
Creator: Carlson, Paul J.; Higgins, Laura L. & Re, Jonathan M.

Accommodating oversize and overweight loads: technical report

Description: "In this report the research project resulted in a statewide map recommending primary and alternate Oversize/ overweight (OS/OW)route networks for the most common origins and destinations based on historical Motor Carrier Division data. Keeping strategic routes open for OS/OW loads and minimizing the number of reroutes along the way will reduce the impedance and unknowns in this critical segment of the motor carrier industry."
Date: July 2012
Creator: Middleton, Daniel R.; Li, Yingfeng; Le, Jerry & Koncz, Nicholas

Alternative methods of flexible base compaction acceptance

Description: "This report summarizes the concerns expressed with the current Texas Department of Transportation(TxDOT) methods, presents approaches some TxDOT districts have taken to overcome problems, and summarizes the current status of other agencies' efforts at mechanistic based acceptance for flexible base. Also this report presents results and findings from a full-scale compaction experiment."
Date: May 2012
Creator: Sebesta, Stephen; Taylor, Ross. & Frazier, James.

Highway safety design workshops

Description: Highway safety is an ongoing concern for the Texas Department of Transportation (TxDOT). As part of its proactive commitment to improving highway safety, TxDOT is moving toward including quantitative safety analyses earlier in the project development process. To assist in achieving this goal, TxDOT research project 0-4703 developed the Roadway Safety Design Workbook for engineers responsible for highway geometric design. This Workbook describes quantitative safety relationships for specific design components known to be correlated with crash frequency. As part of TxDOT Project 0-4703, a series of workshops were developed to share safety information with TxDOT roadway designers. Information in the Workbook was used as the basis for the workshops. The workshops addressed rural highways, urban streets, and freeways. They included a mixture of classroom discussion and hands-on training activities for the participants. The participants indicated that the information presented in the workshops will be beneficial as they make decisions about highway safety improvements.
Date: November 2010
Creator: Bonneson, James A. & Pratt, Michael P.

Identification of priority rail projects for Texas: initial methodology/user manual and guidebook

Description: "This project developed a system of evaluative tools for the Texas Department of Transportation (TxDOT) to prioritize its investments in rail-related projects on a statewide basis. This work is meant to ensure that the limited available funding for rail projects is applied in the most beneficial and efficient manner and is focused upon addressing TxDOT's strategic goals. From the findings, researches recommend a transparent methodology for evaluating proposed rail projects and establishing an initial process through which rail-related investments can periodically be re-evaluated."
Date: February 2012
Creator: Morgan, Curtis Alan

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 3-11 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.

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

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.

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.

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.

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.

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

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

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.

Positive feedback : exploring current approaches in iterative travel demand model implementation

Description: This report looked at the current Texas Department of Transportation Travel Demand Model (TxDOT TDM) and found that they do not include any impedance or accessibility measures in the trip generation step and found that the best approach is to feed back the output from the traffic assignment step to the trip distribution step.
Date: January 2012
Creator: Reeder, Phillip; Bhat, Chandra. & Hall, Kevin.

Safety and economic impacts of converting two-way frontage roads to one-way : methodology and findings

Description: In the research documented here, researchers develop information to communicate the safety and economic impacts of converting frontage roads from two-way to one-way. Researchers studied five locations in Texas where frontage roads were converted from two-way operation to one-way operation. Researchers identified a comparison site in Texas that remained two-way for comparison to four of the treatment (conversion) sites. Researchers developed accident modification factors (AMFs) related to frontage road conversion segments that roadway designers can use to guide frontage road conversion project planning. Researchers developed AMFs based on non-property-damage-only (non-PDO) crashes for segments and interchange intersections. Researchers developed 12 AMFs and provide confidence intervals around the estimates. Researchers describe how the AMFs were developed, associated caveats, and how to apply the AMFs. Researchers also document the process used to build the safety database from electronic data-sets and printed crash reports. Finally, researchers provide recommendations to facilitate and expedite future crash analysis. Researchers attempted to investigate the economic impacts of frontage road conversion by analyzing gross sales data, appraisal data, employment data, and surveys of business owners/managers and customers. Only the appraisal data and survey information were at the parcel level along the corridors and survey sample size was limited.
Date: January 2011
Creator: Eisele, William L.; Yager, Christine E.; Brewer, Marcus A.; Frawley, William E.; Park, Eun Sug; Lord, Dominique et al.