Research Digest, November 2011 issue

Research Digest FORWARD ALL REQUESTS TO: The University of Texas at Austin Center for Transportation Research LIBRARY 1616 Guadalupe St. | Suite 4.202 | Austin, Texas 78701 Phones: (512) 232-3126 and (512) 232-3138 Email: ctrlib@austin.utexas.edu

In this Issue:

TxDOT Research Reports Table of Contents Item 1.

Development of a MASH TL-3 Median Barrier Gate (TTI 1002-2)...................................................

1

Item 2.

Laboratory and Field Evaluations of External Sulfate Attack in Concrete (CTR 4889-1)..................

1

Item 3.

Analysis of the Occurrence and Statistics of Hazardous Materials Spill Incidents along Texas Highways and Suggestions for Mitigation of Transport-Related Spills to Receiving Waters (TechMRT 5200-1)...............................................................................................................................

1

Item 4.

Synthesis and Study of the Roadside Vegetation Establishment Process (TTI 5731-1).....................

2

Item 5.

Use of Rational and Modified Rational Method for Hydraulic Design (TechMRT 6070-1)...............

2

Item 6.

Development of Precast Bridge Deck Overhang System : Technical Report (TTI 6100-3)...............

3

Item 7.

Development of Guidelines for Triple Left and Dual Right-Turn Lanes : Technical Report (TTI 6112-1).......................................................................................................................................

3

Item 8.

Treatments to Reduce the Frequency of Freeway Exit Sign Hits (TTI 6120-1).................................

4

Item 9.

Prototype Design for a Predictive Model to Improve Evacuation Operations : Technical Report (TTI 6121-1)...........................................................................................................................

4

Item 10.

Design of Inclined Loaded Drilled Shafts in High-Plasticity Clay Environment (UTA 6146-1).........

5

Item 11.

Work Zone Positive Protection Guidelines (TTI 6163-1)..................................................................

5

Item 12.

Peer Grouping and Performance Measurement to Improve Rural and Urban Transit in Texas (TTI 6205-1).......................................................................................................................................

6

Item 13.

Rural and Urban Transit District Benchmarking : Effectiveness and Efficiency Guidance Document (TTI 6205-P1/P2)...............................................................................................................

6

Item 14.

Landside Freight Access to Airports : Findings and Case Studies (TTI 6265-1).................................

7

Item 15.

Benefits of Public Roadside Safety Rest Areas in Texas : Technical Report (TTI 6267-2)...............

7

Item 16.

Freight Planning for Texas : Expanding the Dialogue (CTR 6297-1)................................................

8

Item 17.

Rapid Field Detection of Sulfate and Organic Content in Soils : Technical Report (TTI 6362-1)......

9

Item 18.

Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates : Phase I Activities (TTI 6386-2)..........................................................................................................

9

Item 19.

Development of the Texas Revenue Estimator and Needs Determination System (T.R.E.N.D.S.) Model : FY 2010 Activities (TTI 6395-TI-2)............................................................

10

Item 20.

Rural Planning Organizations -- Their Role in Transportation Planning and Project Development in Texas : Technical Report (TTI 6483-1).....................................................................

10

__________________________________________________________________________________________

Research and Technology Implementation Office

November 2011

Research Digest Item 1 Development of a MASH TL-3 Median Barrier Gate TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 1002-2 • 2011 Median barriers are commonly used to separate opposing lanes of traffic on divided highways and to separate managed lanes from general purpose lanes. Concrete median barriers (CMBs) are often preferred on urban freeways with narrow medians due to their minimal deflection and low maintenance. However, long, continuous runs of CMBs limit access of emergency and maintenance vehicles to the other side of a roadway or a managed lane.

Implementation of crashworthy median barrier gates at these locations can maintain the desired level of median protection for motorists while offering improved cross-median access for emergency and/or maintenance vehicles. A new median barrier gate was developed and crash tested under this project. The gate spans a 30-ft opening in a concrete median barrier and consists of two vertically stacked 12-inch x 12-inch x 1/4-inch steel tubes connected to steel end brackets with 2 -inch diameter steel pins. The gate is economical to fabricate and install. It can be manually operated by a single person and is designed to accommodate reversible traffic flow on both sides of the median and be operable in both directions on each end. The median barrier gate satisfies MASH Test Level 3 (TL-3) impact performance criteria and is considered suitable for implementation on Texas highways where cross-median access is desired.

This report is available for free download (24.1 MB): http://tti.tamu.edu/documents/9-1002-2.pdf Item 2 Laboratory and Field Evaluations of External Sulfate Attack in Concrete UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

CTR 4889-1 • 2011 Sulfate attack is a complex form of deterioration that has damaged concrete structures throughout the world. Sulfate attack is particularly complex because the source of sulfates can be external or internal (delayed ettringite formation), and the distress can be chemical in nature, due to alteration of hydration of products, or physical in nature, due to phase changes in the penetrating sulfate solution. Although sulfate attack has been recognized as a cause of concrete distress for many years, it remains a controversial, confusing, and complex topic. There are many unresolved issues, far too many to be tackled in a single investigation. 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.

This report is available for free download (6.1 MB): http://www.utexas.edu/research/ctr/pdf_reports/0_4889_1.pdf Item 3 Analysis of the Occurrence and Statistics of Hazardous Materials Spill Incidents along Texas Highways and Suggestions for Mitigation of Transport-Related Spills to Receiving Waters TEXAS TECH UNIVERSITY. CENTER FOR MULTIDISCIPLINARY RESEARCH IN TRANSPORTATION (TECHMRT)

TechMRT 5200-1 • 2011 The purpose of this report is to present results from research on the occurrence and distribution of hazardous materials spills along Texas highways during the period of Record from 2002-2006.

This report is available for free download (7.1 MB): http://library.ctr.utexas.edu/hostedPDFs/techmrt_0-5200-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 4 Synthesis and Study of the Roadside Vegetation Establishment Process TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 5731-1 • 2011 The Texas Pollutant Discharge Elimination System (TPDES), which is administered and enforced by the Texas Commission on Environmental Quality (TCEQ), requires perennial vegetation to 70 percent of native or adjacent background vegetation before a Notice of Termination (NOT) can be filed. The Texas Department of Transportation's (TxDOT) roadway projects often terminate at times of the year when establishing permanent vegetation is very difficult or nearly impossible. Even when the construction calendar and the ideal growing season line up, establishing vegetation is still a constant challenge. Regions of the state that have limited rainfall and a shorter growing season often take multiple years to establish vegetation to meet the TPDES requirements.

The objective of this study was to provide a more diverse set of tools and options for TxDOT personnel that will help ensure timely vegetation establishment to meet the TPDES regulatory requirements, minimize project delays, and help reduce long-term costs in vegetation development and management. To achieve these objectives, the researchers: (1) compared TxDOT’s practices compare to those of other state departments of transportation (DOTs) and related fields, (2) identified methods for more rapid vegetation establishment for meeting the TPDES requirements using field demonstration plots seeded according to current TxDOT practices, (3) devised a tool to assist design personnel not familiar with the vegetation establishment process, and (4) developed a vegetation establishment field guidebook.

This report is available for free download (Report PDF: 3.3 MB; CD-ROM ZIP file: 75.6 MB): http://tti.tamu.edu/documents/0-5731-1.pdf http://tti.tamu.edu/documents/0-5731-1-CD.zip Item 5 Use of Rational and Modified Rational Method for Hydraulic Design TEXAS TECH UNIVERSITY. CENTER FOR MULTIDISCIPLINARY RESEARCH IN TRANSPORTATION (TECHMRT)

TechMRT 6070-1 • 2011 This report examines the rational and modified rational methods using rainfall-runoff datasets developed from Texas watersheds for application to Texas Department of Transportation hydraulic design problems.

A unified rational method for Texas (URAT) is proposed as an alternative to the conventional method in current use.

URAT substitutes land-use specification, slope influence, and probability adjustments to runoff coefficients by a simple area-weighted coefficient based on functional impervious cover. URAT incorporates the effect of slope and probability adjustments in the specification of the watershed time of equivalence, a characteristic time that makes rational peak discharges and regression equation peak discharges equal at some specified recurrence interval.

An extended application (example) is presented to illustrate how to use the URAT method for both peak discharge and hydrograph estimation. Several appendices document various approaches examined, and provide an extensive examination into the runoff coefficient.

This report is available for free download (26 MB): http://library.ctr.utexas.edu/hostedPDFs/TechMRT_0-6070-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 6 Development of Precast Bridge Deck Overhang System : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6100-3 • 2011 The implementation of full-depth, precast overhang panel systems has the potential to improve constructability, productivity, and make bridges more economical. Initial testing and analyses reported in the 0-6100-2 report resulted in a design that required a large number of shear pockets in the overhang panels. The general design methodology used in this report was to determine the number of connectors based on the shear capacity of a girder with conventional R-bars (not necessarily based on the required demand). The large number of shear pockets reduced the constructability and economy of the precast overhang system. Report 0-6100-1 (produced after 0-6100-2) used the American Association of State Highway Officials Load and Resistance Factor Design (AASHTO LRFD [2008]) demand requirements to design the number of shear pockets for a precast overhang panel system and reported that the number of pockets per panel could be reduced from the numbers reported in report 0-6100-2. However, this report only included an analysis for one beam type and one span length. In addition, the demand load used did not include all factors typically used by designers.

Additional testing was required to assess different connector systems and further analyses were needed for the new Texas Department of Transportation (TxDOT) girders. The testing and analyses documented in this report (0-6100-3) provides a new equation for determining the number of shear pockets required for the various shear connector/coupler systems evaluated in this research. This equation was used to determine the number of shear pockets required for the newer TxDOT girders. Results from this research indicate that the roughened surface provides strong adhesion between the top girder surface and a precast panel. Steel reinforcing hoops placed in the shear pocket and shear reinforcing hoops placed in the overhang panel around the opening of the shear pocket provided limited or no improvement in capacity of the shear connector/coupler system. Hollow structural section (HSS) steel tubes placed around the perimeter of the shear pocket during fabrication did result in samples with higher shear capacities and could result in overhang panels with fewer shear pockets. This system could make constructing bridges with precast overhang systems more constructible, economical, and could reduce the construction time.

This report is available for free download (1.2 MB): http://tti.tamu.edu/documents/0-6100-3.pdf Item 7 Development of Guidelines for Triple Left and Dual Right-Turn Lanes : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6112-1 • 2011 Left- or right-turn lanes at intersections improve safety and operations by separating turning and through vehicles. At intersections with heavy turning demand, it may be necessary to provide multiple turn lanes. Triple left-turn (TLT) and dual right-turn (DRT) lanes are still considered as relatively new designs that many agencies are reluctant to use, so they are somewhat limited in Texas. Guidelines for TLT or DRT lanes are almost nonexistent, leaving traffic engineers to rely on judgment for their designs. Therefore, this research was needed to develop consistent guidance.

The 0-6112 project achieved two primary project goals (1) development of geometric and signal design guidelines for TLT and DRT lanes; and (2) evaluation of the safety and operational performance of TLT and DRT sites in Texas.

This report is available for free download (5.2 MB): http://tti.tamu.edu/documents/0-6112-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 8 Treatments to Reduce the Frequency of Freeway Exit Sign Hits TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6120-1 • 2011 Exit gore signs present a significant maintenance challenge for TxDOT. There is concern regarding the safety of personnel working in gore areas to replace these signs, and the resources necessary for continual maintenance. The objective of this project was to identify and evaluate alternative methods that may reduce the number of sign hits.

Researchers visited several sites with safety problems related to frequent sign hits, determined factors that contribute to sign crashes, and recommended potential treatments. They also evaluated the impact of eliminating exit gore signs at locations where appropriate advance warning with overhead exit signs are provided. Field studies were conducted at two freeway exits in Corpus Christi, Texas. It was found that the lack of exit gore signs at the two freeway exits did not have any negative consequences in terms of vehicle speeds, deceleration behavior, and erratic maneuvers.

This report is available for free download (4.4 MB): http://tti.tamu.edu/documents/0-6120-1.pdf Item 9 Prototype Design for a Predictive Model to Improve Evacuation Operations : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6121-1 • 2011 Mass evacuations of the Texas Gulf Coast remain a difficult challenge. These events are massive in scale, highly complex, and entail an intricate, ever-changing conglomeration of technical and jurisdictional issues. This project focused primarily on the specific issue of developing a new technical tool to help TxDOT and other key operating agencies/stakeholders better predict when major elements of evacuation operations should be implemented. In particular, a variety of technical analyses were employed to develop a new, prototype decision support system that provides additional insights to more effectively decide when evaculane shoulder operations versus full contraflow operations are needed to manage evacuation demand. This new tool has a predictive mechanism designed to provide lead time for implementing these two prospective operational scenarios. The work conducted during this research involved a large-scale application of the DynusT model, and integrates several different factors into the evacuation operation decision-making process namely real-time traffic conditions, hurricane characteristics (strength and size) and human behavior.

This report is available for free download (6.4 MB): http://tti.tamu.edu/documents/0-6121-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 10 Design of Inclined Loaded Drilled Shafts in High-Plasticity Clay Environment UNIVERSITY OF TEXAS AT ARLINGTON. DEPARTMENT OF CIVIL ENGINEERING

UTA 6146-1 • 2011 Drilled shaft foundations are principally used to support many structures such as bridge piers, towers, buildings, transmission towers, and roadway cable barriers. This research focuses on the use of drilled shafts in the cable median barrier systems which play an important role in protecting people’s lives due to cross-over collisions on highways.

During December 2006 to February 2007, several failures of 3-cable median barrier (TL-3) were observed in Kaufman County near Dallas without any traffic-related vehicular impacts.

Preliminary investigation of failures showed that failed drilled shafts were located in high plasticity clay. Causes of failures are attributed to cold temperature induced shrinkage in the cables that increased in the tension in them, soil saturation due to long periods of rainfall and small sizes of drilled shafts used. Various sizes of drilled shafts were established and constructed in an environment similar to the one in which foundation distress was observed.

Geotechnical sampling and laboratory testing were performed, and a new test setup for the application of an inclined tensile loading on drilled shafts was designed to simulate the loading under real field conditions. The capacities of different sizes of drilled shafts from field test were tested and measured under this setup. Once good simulation was obtained, the models are used for various foundation dimensions and various undrained shear strengths of soils which, in turn, provided results that are used in the development of foundation design charts. Additionally, construction guidelines and recommendation for periodic maintenance are provided in this report.

This report is available for free download (7.2 MB): http://tti.tamu.edu/documents/0-6146-1.pdf Item 11 Work Zone Positive Protection Guidelines TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6163-1 • 2011 The goal of this project was to develop implementation guidance that the Texas Department of Transportation (TxDOT) can use to make better decisions regarding when and where to use positive protection in work zones and when to consider exposure control and other traffic control measures that could improve work zone safety. The specific objectives of the project were as follows: - Analyze the benefits and costs of using portable concrete barrier (PCB) for positive protection in work zones.

- Analyze the benefits and costs associated with the use of moveable and portable barrier technologies that can be more quickly deployed and removed at work sites than traditional PCB. - Analyze the benefits and costs of non-positive protection devices that can be used to improve safety and reduce work zone intrusion events in work zones.

- Develop implementation guidelines for these various technologies.

Researchers also developed guidelines for portable concrete barrier use in work zones. Guidelines regarding the use of portable steel barrier, mobile barrier, and truck-mounted attenuators were also developed. General guidance and information regarding the use of exposure control measures and other traffic control measures to reduce work space intrusion risks were also included in this report.

This report is available for free download (2.0 MB): http://tti.tamu.edu/documents/0-6163-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 12 Peer Grouping and Performance Measurement to Improve Rural and Urban Transit in Texas TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6205-1 • 2011 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.

This report is available for free download (2.5 MB): http://tti.tamu.edu/documents/0-6205-1.pdf Item 13 Rural and Urban Transit District Benchmarking : Effectiveness and Efficiency Guidance Document TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6205-P1/P2 • 2011 Rural and urban transit systems have sought ways to compare performance across agencies, identifying successful service delivery strategies and applying these concepts to achieve successful results within their agency.

Benchmarking is a method used to accomplish this goal. Benchmarking is a means of comparing performance to an established performance baseline. Benchmarks are typically established through the process of identifying successful business practices through performance measurement.

This guidance document establishes peer groupings for rural and urban transit districts, calculates effectiveness and efficiency factors within the peer groups, and identifies transferrable elements of high performers that may provide transit districts information applicable to improve their own performance. The goal of this guidance document is to help rural and urban transit districts better understand and set targets for performance, increasing the return on federal and state transit investment.

This report is available for free download (634 KB): http://tti.tamu.edu/documents/0-6205-P1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 14 Landside Freight Access to Airports : Findings and Case Studies TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6265-1 • 2011 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.

This report is available for free download (102 MB): http://tti.tamu.edu/documents/0-6265-1.pdf Item 15 Benefits of Public Roadside Safety Rest Areas in Texas : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6267-2 • 2011 The objective of this investigation was to develop a benefit-cost analysis methodology for safety rest areas in Texas and to demonstrate its application in select corridors throughout the state. In addition, this project considered novel safety rest area development approaches that could reduce the public cost burden borne by individual public agencies. Based upon the available supporting data for Texas, a benefit-cost ratio relationship was developed that included safety, comfort and convenience, and excess travel and diversion benefits accrued by highway users; direct monetary benefits accrued by highway or other public agencies; economic development/tourism and specific business enterprise benefits accrued by external entities and direct monetary cost accrued by highway or other public agencies.

The resulting method utilizes timely and relevant data and national/aggregate unit values, whose sources are carefully documented to ensure defensibility and repeatability of the benefit-cost ratios estimated for Texas. A noted shortcoming of the applied method is that it is heavily assumption-based--minor changes to any of the assumed values will influence the resultant benefit-cost ratios, although it is unclear to what extent these ratios would change.

A second shortcoming not unique to this methodology related to the quality and accessibility of supporting data, which challenged and in some instances prevented estimation of individual benefit and cost component estimates-both within and between the three demonstration corridors--suggests limitations to the transferability of these results.

This report is available for free download (3.1 MB): http://tti.tamu.edu/documents/0-6267-2.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 16 Freight Planning for Texas : Expanding the Dialogue UNIVERSITY OF TEXAS AT AUSTIN. CENTER FOR TRANSPORTATION RESEARCH (CTR)

CTR 6297-1 • 2011 Efficient, reliable, and safe freight transportation is critical to the economic prosperity of any region. An efficient multimodal and intermodal transportation system reduces transportation and supply chain transaction costs and increases connectivity, reliability, and accessibility to local and global markets. An efficient freight transportation system, therefore, supports economic development and the expansion of international trade, increases national employment and growth in personal income and the Gross Domestic Product of a region, and improves the quality of life of its citizens. Intermodal and freight concerns have thus received increasing attention in the wake of globalization, increasing congestion, and changes in the logistics structure of shippers to facilitate just-in-time production. Both the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 and the subsequent reauthorization of the Transportation Equity Act of the 21st Century (TEA-21) have identified an understanding of the needs of the freight transportation sector as a critical component of transportation planning.

This study sought to (a) improve the understanding of the size, scope, and type of commodities that are produced, consumed, and moved through different regions in the Texas, (b) gain an insight into the business and transportation system factors that shippers and receivers consider when making shipping decisions, (c) identify and describe factors that impact the competiveness of multimodal freight modes operation in Texas, (d) provide commodity data regarding origin and destination flows that will facilitate updates to various Texas freight models and studies, (e) identify and document significant multimodal freight system trends, needs, and issues in Texas, (f) recommend freight policies, strategies, performance measures, and infrastructure improvements that TxDOT can consider for implementation and funding, and (g) explore the interest, feasibility, and requirements for forming a Freight Advisory Committee in Texas.

A Relational Multimodal Freight Database software populated with available freight data is available on an attached CD with a user guide [or as a large ZIP file for online users]. The database contains freight data from numerous sources such as the Freight Analysis Framework; North American Transborder Freight Data; Annual Coal Report; Border Crossing Data; Maritime Administration Data; Fresh Fruit and Vegetable Shipments by Commodities, States and Months; National Transportation Statistics; USA Trade Data; Waterborne Commerce Statistics of USA; and the Carload Waybill Public Use File.

A second CD provides extensive documentation of freight stakeholder input and analysis [Appendices A-C]. It is available to online users as a ZIP file.

This report is available for free download (Report PDF: 1.5 MB, Appendices: 21.6 MB, ZIP Database: 233.5 MB): http://www.utexas.edu/research/ctr/pdf_reports/0_6297_1.pdf http://library.ctr.utexas.edu/digitized/zipfiles/0-6297-1-AppendixA-C.zip http://www.utexas.edu/research/ctr/pdf_reports/0-6297-1.zip

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 17 Rapid Field Detection of Sulfate and Organic Content in Soils : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6362-1 • 2011 In recent years, the Texas Department of Transportation (TxDOT) has experienced problems chemically stabilizing moderate to high plasticity clay soils with calcium-based additives. Many of the problems are the result of soluble sulfate minerals in the soil reacting with the lime or cement added for stabilization. The occurrence of these deposits is unpredictable and often restricted to small areas. To address this problem, the researchers set about identifying a technique that provides a map showing the sulfate content of the soil over a large area to a depth of 3 to 4 ft. Two technologies were identified that provide an indirect measurement of sulfate salts (an electromagnetic device - EM-38, and a soil conductivity device - VERIS 3150). We tested these devices on three different TxDOT projects in different parts of the state that have been known for high sulfate contents. We collected soil samples at 1 ft intervals to a depth of 4 ft where the data varied. We measured the PI, moisture content, sulfate content, and organic content in each sample. We then ran multivariate statistical analyses to correlate the conductivity data collected with the VERIS 3150 to laboratory-measured soil properties. We observed that coil conductivity is related to the soil texture/clay content, moisture content, and dissolved salts (i.e., sulfate and other salt minerals). We noted that for all of the projects tested, a soil conductivity over 100 mS/m may contain problematic sulfate levels, but it may also be due to high plasticity clay soils and/or high moisture contents with other dissolved salts. What is noteworthy about this research is it provides a tool to intelligently decide where to collect soil samples in a grid pattern of analyze for problematic sulfate levels versus the current method of collecting soil samples in a grid pattern of a specified interval that may be too large and not detect problematic sulfate levels until the road explodes.

This report is available for free download (4.9 MB): http://tti.tamu.edu/documents/0-6362-1.pdf

Item 18 Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates : Phase I Activities TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6386-2 • 2011 This report documents the results of two completed Phase I tasks for the project titled, "Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates." These tasks involved a literature review and a review of the current Texas Pavement Management Information System (PMIS) score process.

The objective of the project is to develop improvements to PMIS to meet the needs of the Texas Department of Transportation (TxDOT). The project is split into three phases. Phase I involves a review of the current PMIS and recommendations for modifying and improving analytical processes in the system. Phase II involves developing pavement performance models for the system. Finally, Phase III involves developing improved decision trees for the system's needs estimate process.

The first project task involved developing a synthesis on how states define and measure pavement scores; that synthesis was published in February 2009. The other Phase I tasks for this project are currently ongoing; the results of all remaining tasks will be documented in the final report for this project.

This report is available for free download (7.8 MB): http://tti.tamu.edu/documents/0-6386-2.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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Research Digest Item 19 Development of the Texas Revenue Estimator and Needs Determination System (T.R.E.N.D.S.) Model : FY 2010 Activities TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6395-TI-2 • 2011 The T.R.E.N.D.S. model provides transportation planners, policy makers, and the public a tool to forecast revenues and expenses for the Texas Department of Transportation for the period 2010 through 2035 based on a user-defined level of transportation investment. The user, through interactive windows, can control a number of variables related to assumptions regarding statewide transportation needs, population growth rates, fuel efficiency, federal reimbursement rates, inflation rates, taxes, fees, and other elements. The output is a set of tables and graphs showing a forecast of revenues, expenditures, and fund balances for each year of the analysis period based on the user-defined assumptions. During FY 2010, a new module providing local option revenue projections was added. The analysis area for this module is the Metropolitan Planning Organization (MPO).

This report is available for free download (1.5 MB): http://tti.tamu.edu/documents/0-6395-TI-2.pdf Item 20 Rural Planning Organizations -- Their Role in Transportation Planning and Project Development in Texas : Technical Report TEXAS A&M UNIVERSITY. TEXAS TRANSPORTATION INSTITUTE (TTI)

TTI 6483-1 • 2011 While a formal planning and programming process is established for urbanized areas through Metropolitan Planning Organizations, no similar requirement has been established for rural areas. Currently, under the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users, states are required to consult with non-metropolitan local officials in transportation planning and programming. The consultation process between state Departments of Transportation (DOT) and non-metropolitan local officials is not prescribed in the planning rules, and consultation practices vary widely among each state's DOT. Historically, the Texas Department of Transportation (TxDOT) has worked in cooperation with each individual rural county to plan and program projects. This has often resulted in a county-by-county project lists that the TxDOT districts must try to fashion into a regional strategy or plan. A need exists to examine the concept of rural planning organizations and research their use in Texas to determine if a formal rural planning organization may offer a means to improve transportation planning and programming. The objective of this research is to identify and examine rural planning organizations, their structure and operation, and their role in transportation planning and programming. The project will include a review of current processes used by TxDOT and other agencies to plan and program transportation projects in rural areas.

This report is available for free download (11.5 MB): http://tti.tamu.edu/documents/0-6483-1.pdf

__________________________________________________________________________________ Research and Technology Implementation Office

November 2011

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