Search Results

Evaluating existing culverts for load capacity allowing for soil structure interaction

Description: This study explores culvert load rating practices and procedures as applied to the Texas Department of Transportation's (TxDOT's) archive of 1477 culvert designs and their inventory of more than 13,000 in-service reinforced concrete box culverts. The problem is that when older culverts are load-rated based on current AASHTO policy, many competent, serviceable culverts are shown to be deficient, requiring load posting, retrofit or replacement. A disconnect exists between culvert structural analysis practices and actual culvert performance. To address this challenge, the research focused on development of a clear, repeatable and reliable procedure for TxDOT engineers and their consultants to use for load rating culverts in the TxDOT roadway system. Articulated in TxDOT's Culvert Rating Guide, the new load rating procedure uses three increasingly-sophisticated analysis approaches, ranging from a direct stiffness frame model to a production-oriented finite element model which accounts for soil-structure interaction. Validation of the Culvert Rating Guide involved three major tasks. First, the researchers load-rated a statistically representative sample of 100 of TxDOT's culvert designs. Second, a parametric study was performed to evaluate six independent variables associated with culvert load rating. Third, instrumented load tests on three in-service culverts were conducted to compare measured demands with predicted values. This work showed that the analytical methods in the Culvert Rating Guide produce conservative load ratings yet still allow for reduction in excess over-conservatism in the load rating process.
Date: December 2010
Creator: Lawson, William D.; Wood, Timothy A.; Newhouse, Charles D. & Jayawickrama, Priyantha W.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of a MASH TL-2 guardrail-to-bridge rail transition compatible with 31-inch guardrail

Description: The TxDOT Design Division is in the process of developing new guardrail standards that comply with the AASHTO Manual for Assessing Safety Hardware (MASH). The new guardrail system will provide increased capacity and improved impact performance relative to the current design. A key feature of the new system is an increased in rail mounting height from 27 inches to 31 inches. TxDOT's current TL-2 metal beam transition is 27 inches tall and is not compatible with the new 31 inch guardrail system. While the high-speed, nested thrie beam transition system meets MASH guidelines and is compatible with a 31-inch guardrail, it would be cost-prohibitive to use it on all roadways. The objective of this research was to develop a transition that is suitable for use on lower speed roadways, less expensive and complex than the current high-speed (i.e., TL-3) transition design, and is compatible with a 31-inch guardrail. A low-cost guardrail-to-bridge rail transition was successfully developed and tested under MASH Test Level 2 conditions. It is compatible with a 31-inch guardrail and can connect to rigid concrete bridge rails. It is considered suitable for implementation on roadways that have traffic conditions appropriate for the use of TL-2 safety hardware. Use of this system provides significant savings in material and installation cost compared to the high speed transition system.
Date: December 2011
Creator: Bligh, Roger P.; Arrington, Dusty R. & Menges, Wanda L.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Catalog of effective treatments to improve driver and worker safety at short-term work zones

Description: "This report catalogs several devices that were found to be effective at improving driver and worker safety at short-term work zones. The services include are: fluorescent yellow-green worker vests and hard hat covers, portable variable message signs, speed display trailers, fluorescent orange roll-up signs, radar drones, and retroreflective magnetic strips for work vehicles. The catalog provides a brief description of each treatment, along with a summary of the treatment's effectiveness, and recommendations for its use at short-term work zones."
Date: January 2001
Creator: Fontaine, Michael D. & Hawkins, H. Gene
Item Type: Book
Partner: UNT Libraries Government Documents Department

TxDOT uses of real-time commercial traffic data : opportunity matrix

Description: Based on a TxDOT survey, a review of other state DOTs, and researcher understanding of Intelligent Transportation System (ITS) needs, the Texas Transportation Institute (TTI) team developed a comprehensive list of opportunities for TxDOT to consider pertaining to future use of private sector (PS) data. Specific opportunities for applying private data were reviewed in light of accuracy of the data, coverage areas, data availability, cost, and control of the data stream.
Date: January 2012
Creator: Middleton, Dan; Brydia, Robert; Kraus, Edgar; Cheu, Kelvin; Rajbhandari, Rajat, 1973-; Songchitruksa, Praprut et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Rapid field detection of sulfate and organic content in soils : technical report

Description: Report regarding efforts to identify a technique to map the sulfate content of soil over a large area to a depth of 3 to 4 feet. Two devices are noted: an electromagnetic device called EM-38 and a soil conductivity device called VERIS 315.
Date: October 2010
Creator: Harvey, Omar; Sebesta, Stephen & Harris, Pat
Item Type: Report
Partner: UNT Libraries Government Documents Department

Proposed TxDOT strategic research program

Description: "This report documents the results of the work conducted by the Center for Transportation Research (CTR) at the University of Texas at Austin, the Texas Transportation Institute (TTI), and The Center for Multidisciplinary Research in Transportation (TechMRT) at Texas Tech University, to assist TxDOT in developing the elements of the SRP."
Date: October 2010
Creator: Persad, Khali (Khali Ram), 1956-; Gilliland, Cynthia A. Weatherby; Nash, Phil; Machemehl, Randy B.; Stockton, Bill & Cleveland, Theodore
Item Type: Report
Partner: UNT Libraries Government Documents Department

Benefits of public roadside safety rest areas in Texas : technical report

Description: Report regarding efforts to develop a benefit-cost analysis methodology for safety rest areas in Texas and to demonstrate its application in select corridors throughout the state. This project also considers approaches to developing rest areas that could reduce costs to the public.
Date: May 2011
Creator: Carson, Jodi L.; Pezoldt, Val J.; Koncz, Nicholas A., 1964- & Obeng-Boampong, Kwaku Oduro, 1977-
Item Type: Report
Partner: UNT Libraries Government Documents Department

Materials selection for concrete overlays : information survey review and evaluation of existing concrete overlays in Texas

Description: "A comprehensive search and review of the use of concrete overlays by the TxDOT districts as well as other DOTs was conducted, with special emphasis focused on gathering information about the constituent materials and mixture proportioning used in the concrete overlays. This review also included new materials such as fibers used in previous studies and new types of fibers currently available. Publications and articles covering the various overlay rehabilitations were used as the background this project, as well as the several studies and implementation projects have been conducted for TxDOT."
Date: April 2011
Creator: Kim, Dong Hyun; Trevino, Manuel; Whitney, David P. & Ferron, Raissa
Item Type: Report
Partner: UNT Libraries Government Documents Department

Design and application of accessible land-use modeling tools for Texas regions

Description: "This report consists of two parts. The first summarizes key details of the Suitability Analysis (SA) model, while the second illustrates the implementation details of the Gravity Land-Use Model (G-LUM). Both modeling approaches have been applied to the Austing region of Texas, but for different case study examples."
Date: August 2010
Creator: Kockelman, Kara; Anjomani, Ardeshir; Paul, Binny M.; Nostikasai, Dian; Tayyebi, Ali & Kharel, Gehandra
Item Type: Report
Partner: UNT Libraries Government Documents Department

Determination of minimum height and lateral design load for MASH test level 4 bridge rails

Description: "This research had the objectives of determining the minimum rail height and lateral design impact load for MASH test level 4 bridge rails. Using parametric finite element analysis and subsequent crash testing, the researchers determined the minimum recommended rail height for MASH TL-4 impact conditions to be 36 inches. Later Design impact for MASH TL-4 test conditions was determined to be 80 kips."
Date: October 2011
Creator: Bligh, Roger P.; Menges, Wanda L. & Sheikh, Nauman Mansoor
Item Type: Report
Partner: UNT Libraries Government Documents Department

Peer state assessment of TxDOT maintenance program and practices: workshop and road rally findings

Description: "The goal of the project was to conduct a workshop at CTR and in the Austin District that would educate the visiting peers on TxDOT"s maintenance practices and invite their feedback."
Date: January 2011
Creator: Gao, Lu; Chi, Seokho; Prozzi, Jorge Alberto; Yildirim, Yetkin; Zhang, Zhanmin; Centurion, Claudia et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Laboratory and field evaluations of external sulfate attack in concrete

Description: "The research described in this report aims to address several of these lingering issues, especially those that are particularly relevant to the state of Texas."
Date: January 2011
Creator: Drimalas, Thanos; Clement, John C.; Folliard, Kevin J.; Dhole, Raj & Thomas, Michael D. A.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Fatigue life of steel base plate to pole connections for traffic structures

Description: "This is a final report of an extensive experimental and analytical examination of the fatigue behavior of the welded end connection used on high-mast light structures and traffic signal masts. The weld details commonly used for these connections produce very poor fatigue performance. Their performance is a function of base plate stiffness, weld type and geometry, and number of anchor bolts. Recommended connections and their corresponding fatigue strength are given as well as recommended fabrication and welding specifications."
Date: January 2011
Creator: Stam, Andrew Philip; Frank, Karl H.; Stern, A. P.; Anderson, T. H. & Richman, N. B.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Validation and implementation of the structural condition index (SCI) for network-level pavement evaluation

Description: "The objective of this research is to validate the pavement Structural Condition Index (SCI) developed under a previous Research Project, 0-4322, and to develop guidelines for implementing the SCI at the network level."
Date: June 2011
Creator: Murphy, Michael; Zhang, Zhanmin & Peddibhotla, Sree Sravya Sruthi
Item Type: Report
Partner: UNT Libraries Government Documents Department

Laboratory Evaluation of Constructibility Issues with Surface Treatment Binder

Description: This report discusses a study related to the use of emulsified asphalt (EA) as a binder for sealing roads after construction. Due to the number complex variables that affect EAs, this research is meant to help TxDOT personnel better predict which EA will be most effective and bond most quickly to allow roads to open for traffic.
Date: October 2011
Creator: Senadheera, Sanjaya Priyantha, 1959-; Prozzi, Jorge Alberto; Smit, Andre; Bannerjee, Ambarish; Tubb, Andrew & Niu, Lei
Item Type: Report
Partner: UNT Libraries Government Documents Department

Rural planning organizations, their role in transportation planning and project development in Texas : technical report

Description: Report containing research identifying and examining rural planning organizations, their structure and operation, and their role in transportation planning and programming.
Date: October 2010
Creator: Overman, John H.; Ellis, Patricia; Frawley, William; Taylor, Ryan; Geiselbrecht, Tina & Goodin, Ginger
Item Type: Report
Partner: UNT Libraries Government Documents Department

Lane assignment traffic control devices on frontage roads and conventional roads at interchanges

Description: "This project conducted state-of-the-practice surveys, focus groups, and driver surveys to develop test signs used for field deployment and evaluation regarding lane assignment on frontage roads and cross streets."
Date: October 2010
Creator: Nelson, Alicia A.; Tydlacka, Jonathan M.; Stevens, Roma G.; Chrysler, Susan T. & Voigt, Anthon P.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Assessing the environmental justice impacts of toll road projects

Description: "The objective of this study was to extend the work that was conducted under TxDOT Research Project 0-5208 by (a) reviewing the ability of available tools and analysis techniques to quantify and qualitatively describe the (environmental justice) EJ impacts associated with toll road projects and toll road systems through an evaluation of state-of-the-practice applications, and (b) recommending a suitable approach to assess the EJ impacts of toll roads and toll road systems on EJ communities."
Date: October 2010
Creator: Prozzi, Jolanda; Carroll, Lindsey; Loftus-Otway, Lisa Dawn; Bhat, Chandra; Paleti, Rajesh & McCray, Talia M.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of a MASH TL-3 median barrier gate

Description: Report regarding a median barrier gate designed to both offer protection to motorists and easier cross-median access for emergency and maintenance vehicles.
Date: February 2011
Creator: Bligh, Roger P.; Arrington, Dusty R.; Sheikh, Nauman Mansoor; Silvestri, Chiara & Menges, Wanda L.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Texas Transportation Researcher, Volume 47, Number 4, 2011

Description: Quarterly publication of the Texas A&M Transportation Institute discussing their research as well as professional and service activities. It includes articles about research and innovations in various areas related to transportation in Texas.
Date: 2011
Creator: Texas A & M Transportation Institute
Partner: UNT Libraries Government Documents Department

Texas roundabout guidelines : final report

Description: "This report contains best practices for choosing appropriate locations and design concepts for Texas roundabouts. This research effort is comprised of the following components: synthesis of available literature and analysis methods, development of capacity analysis methods, validation and enhancement of existing tools, and a spreadsheet tool to aid in roundabout planning and implementation."
Date: October 2011
Creator: Mills, Alison; Duthie, Jen; Machemehl, Randy B.; Ferguson, Erin; Waller, Travis; Sun, Dazhi et al.
Item Type: Book
Partner: UNT Libraries Government Documents Department