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Designing Fine Aggregate Mixtures to evaluate fatigue crack growth in asphalt mixtures

Description: "Fatigue cracking is a significant form of pavement distress in flexible pavements. The properties of the sand-asphalt mortars or fine aggregate matrix (FAM) can be used to characterize the evolution of fatigue crack growth and self-healing in asphalt mixtures. This study compares the internal microstructure of the mortar within a full asphalt mixture to the internal microstructure of the FAM specimen. This study also conducts a limited evaluation of the influence of mixture properties and methods of compaction on the engineering properties of the FAM specimens. The results from this study, although limited in number, indicate that in most cases the SGC compacted FAM specimen had a microstructure that most closely resembled the microstructure of the mortar within a full asphalt mixture. Another finding from this study was that, at a given level of damage, the healing characteristic of the three different types of FAM mixes was not significantly different. This indicates that the healing rate is mostly dictated by the type of binder and not significantly influenced by the gradation or binder content, as long as the volumetric distribution of the mastic was the same. In other words, the inherent healing characteristics of the asphalt binder play a more significant role relative to other properties (e.g. volumetrics) in the overall fatigue cracking resistance of the asphalt mixture."
Date: April 2001
Creator: Bhasin, Amit; Motamed, Arash & Izadi, Anoosha

Portable Emission Measurement System-based approach to developing and evaluating driving cycles for air quality assessment

Description: "The first objective is to develop driving cycles for classified roads incorporating both a vehicle's driving activities and its emission characteristics, using the data collected by Portable Emission Measurement System (PEMS), which was neither available nor has ever been used in developing driving cycles. A comprehensive database is established for the collected data and a sophisticated computer program is developed to generate the specific driving cycles. The second objective is to develop an evaluation approach of driving cycles in which Vehicle Specific Power (VSP), a parameter that can readily connect the driving modes with emissions, is used to evaluate how well the driving cycles can represent the driving and emission characteristics on real roads."
Date: April 2010
Creator: Wang, Ziqianli; Shi, Qinyi & Lei, Yu

Impacts of pending federal greenhouse gas legislation on the Texas transportation sector

Description: "This 2010 study, funded by the Southwest Region University Transportation Center, assesses current regulatory attempts to mitigate climate change and how such proposed action would impact the Texas transportation sector economically. Social and political trends suggest the United States may soon join other United Nations Framework Convention on Climate Change (UNFCCC) countries in drafting substantive, national climate change policy. After providing a brief overview of past and present climate efforts taken both nationally and internationally, this paper explores different economic solutions to address the externalities of fossil fuel emissions. Alternatives include command-and-control regulation, a carbon tax, and a cap-and-trade program. Several factors, including the difficulty of quantifying and constraining greenhouse gas emissions downstream at the vehicle tailpipe, suggest a carbon tax levied upon upstream refiners is the most promising market-based alternative to reduce carbon emissions within the United States's transportation sector. Texas business leaders and lawmakers have repeatedly voiced their disapproval of mandatory national carbon controls over the past decade. A crucial factor why much of the Lone Star State's populace remains opposed to climate change action is Texas leads the nation's energy industry, which is decidedly fossil-fuel based and therefore carbon intensive. Prevailing thought is a carbon tax would only elevate fuel prices increasing the cost of residential and commercial activity heavily dependent on motor vehicles. This paper articulates how greenhouse gas legislation may financially impact transportation within the Lone Star State and concludes with ways energy and environmental policymakers can build consensus within Texas to address the carbon externality."
Date: May 2010
Creator: Woodward, James T. & Boske, Leigh B.

A comprehensive examination of heavy vehicle emissions factors

Description: "This report summarized the findings from reviewing the literature on several topics that are related to heavy vehicle emissions including engine and fuel types, vehicle technologies that can be used to reduce or mitigate vehicle emission, the factors that affect vehicle emission, vehicle emissions modeling, and current and future policy requiring accurate accounting of heavy vehicle emission."
Date: August 2010
Creator: Thompson, Melissa Renee; Unnikrishnan, Avinash; Conway, Alison J. & Walton, C. Michael

Network methods for project selection based on optimizing environmental impact

Description: "Traditionally, transportation road networks have been designed for minimal congestion. Unfortunately, such approaches do not guarantee minimal vehicle emissions. Given the negative impacts of vehicle pollutants as well as tighter national air quality standards, it is critical for regions to be able to identify capacity modifications to road networks such that vehicle emission are minimal. This ability combined with land use changes and opportunities for non-auto travel are paramount in helping regions improve air quality."
Date: August 2010
Creator: Duthie, Jennifer Clare; Waller, S. Travis & Ferguson, Erin M.

Performance analysis of the "zoning" strategies for Americans with Disabilities Act paratransit services

Description: "The objective of this research is to provide a more in-depth evaluation and comparison between centralized and decentralized zoning strategies for the city of Houston, Texas, by developing a simulation model to evaluate the effect of zoning strategies on the productivity and service quality for the ADA paratransit service."
Date: August 2010
Creator: Shen, Chung-Wei & Quadrifoglio, Luca

Predicting the incremental effects on transit ridership due to Bus-On-Shoulder operations

Description: "Bus-On-Shoulder (BOS) operations are an extremely effective method for increasing the quality of a bus service; allowing for a bus to use a freeway shoulder as a bypass lane not only decreases bus travel time but also increases the bus service's overall performance. BOS has also been found to increase bus ridership. The modern BOS system began in the Minneapolis-Saint Paul area almost 20 years ago. Using the extensive data available from Minneapolis-Saint Paul, ridership changes due to BOS operations were explored. The data showed that with 90% confidence, ridership will increase by at least 4.5% and as much as 14.3%. This paper also explores how the citizens of Austin, Texas would respond to a BOS operation on local freeways. A stated preference survey was administered to a sample of Austin commuters. It was determined that potential riders would desire a time savings of 7 or more minutes. Typically it is challenging for persons to accurately predict time savings, therefore it was concluded that for a BOS operation to be successful it was necessary for a there to be a perceived time savings."
Date: August 2010
Creator: Machemehl, Randy B. & Pappas, Elani

Transportation for humanity: meeting the needs in the colonias

Description: "The goal of the research was to access the current transportation challenges facing residents of the colonias and determine the feasibility of vehicle procurement through donations or at-cost purchases from a variety of entities and/or individuals to support the program, and recommendations for alternative funding mechanisms to support the local community centers in their efforts to provide transportation to the colonias population."
Date: September 2010
Creator: Storey, Beverly B. & Jasek, Debbie

An evaluation of the effects of transit oriented development in a suburban environment

Description: "Transit-Oriented Development (TOD) refers to dense, pedestrian-friendly, livable communities that have good transit as a nucleus. While transit facilities are missing in most suburban towns and the residents are heavily dependent on their vehicles, it is wondered whether residents would take advantage if public facilities were available. This paper presents information about some vital aspects of TOD when viewed in suburban communities."
Date: October 2010
Creator: Lewis, Carol Abel & Lastrape, Krystal M.

Examining the Role of Trip Length in Commuter Decisions to Use Public Transportation

Description: Report that examines traveler trip lengths across transit modes, work trip duration frequency distributions and mode share distributions in 7 major cities, 8 Combined Statistical Areas and one Metropolitan Statisical Area and found the effects of increasing population and transit mdoe gvariety on work trip travel time and travel distance.
Date: October 2010
Creator: Yu, Yao & Machemehl, Randy

Partnering with AVID to create transportation scholars

Description: "The goal of this project was to team with the Advancement Via Individual Determination (AVID) program in local schools to stimulate student awareness of transportation and engineering careers and to encourage interest in the science, technology, engineering, and mathematics (STEM) fields."
Date: October 2010
Creator: Jasek, Debbie & Finley, Melisa D.

Quantitative characterization of microstructure of asphalt mixtures

Description: "The main objective of this study was to quantitatively characterize the three dimensional micro-structure of the asphalt binder withing the fine aggregate matrix of an asphalt mixture and compare the influence of binder content, coarse aggregate gradation, and fine aggregate gradation on this micro-structure."
Date: October 2010
Creator: Badgekar, Swapneel; Bhasin, Amit & Izadi, Anoosha

Export growth, energy costs, and sustainable supply chains

Description: "The report examines sustainable supply chains in North America and the role played by rail inter-modal operations in lowering ten-mile fuel and emission costs. It examines whether current systems favor imports over exports - a current complaint from some shippers - and whether the development of inland inter-modal ports offers a solution to moving future freight into and out of large metropolitan areas."
Date: November 2010
Creator: Harrison, Rob & Seedah, Dan