Results of the 2009-10 Campus Travel Survey

The campus travel survey is a joint effort by the Transportation & Parking Services (TAPS) on campus and the Sustainable Transportation Center, part of the Institute of Transportation Studies at UC Davis, meant to be administered annually each fall by a graduate student at the Institute of Transportation Studies. The main purpose of the survey is to collect annual data on how the UC Davis community travels to campus, including mode choice, vehicle occupancy, distances traveled, and vehicle/bicycle parking. It also offers an opportunity for TAPS to assess awareness of campus transportation services and perceptions of mobility options. This year\u2019s survey is the fourth administration of the Campus Travel Survey, which was first administered in the spring of 2006-07 as a pilot effort

Results of the 2011-12 Campus Travel Survey

The UC Davis campus travel survey, a joint effort by the Transportation and Parking Services and the Institute of Transportation Studies, collects annual data on travel to campus, including mode choice, vehicle occupancy, distances traveled, and carbon emissions. Survey results are used to assess awareness and utilization of campus transportation services and estimate demand for new services designed to promote sustainable commuting. Data also provide researchers with insights about the effects of attitudes and perceptions of mobility options on commute mode choice. Almost half of those physically traveling to campus on a typical day bike to the campus while about one-quarter drive alone. Results indicate that biking is increasing and the amount of carbon dioxide produced by commuters is decreasing

Results of the 2010-11 Campus Travel Survey

The University of California, Davis, collect data each year on how the UC Davis community travels to campus, including mode choice, vehicle occupancy, distances traveled, and vehicle/bicycle parking. It also offers an opportunity for campus transportation services to assess awareness of campus transportation services and perceptions of mobility options. Most respondents live on the campus or in the city of Davis; 41% percent of respondents travel to campus by bike,33% by personal vehicle, 20% percent by public transit and 6% percent by walking. This modal split reflects the well-developed bicycle infrastructure in Davis. No statistically significant change was noted in the modal split between 2008-09 and 2020-11 but the percent of those physically traveling to campus is 3.3 percentage points lower than in 2007-08, an important change for its potential environmental impact and implications for campus planning

Integrated and Data-Driven Transportation Infrastructure Management through Consideration of Life Cycle Costs and Environmental Impacts

ProQuest does not claim copyright in the individual underlying works. Citation: Saboori, A. (2020). Integrated and Data-Driven Transportation Infrastructure Management through Consideration of Life Cycle Costs and Environmental Impacts. UC Davis: Institute of Transportation Studies. Retrieved from https://escholarship.org/uc/item/8hx398vvThe main goal of this dissertation was to develop frameworks, quantitative models, and databases needed to support data-driven, informed, and integrated decision-making in managing the vast transportation infrastructure in California. Such a management system was envisioned to consider both costs and environmental impacts of management decisions, based on full life cycles of the infrastructure, and using reliable, high quality data that well represent local conditions in terms of materials and energy sources, production technologies, design methods, construction practices, and other critical parameters. This PhD research consisted of three parts: (1) development of a comprehensive life cycle inventory (LCI) database for implementation of life cycle assessment (LCA) methodology in transportation infrastructure management in California; (2) evaluation of current and potential sustainability actions at the state and local government levels through the development of frameworks, models, and datasets needed for objective and accurate quantification of the impacts of management decisions; (3) assessment of recycling practices available for pavements at their end of life to quantify changes in environmental impacts compared to conventional methods, considering the effects of recycling through the use stage

Sanitization of Transportation Data: Policy Implications and Gaps

UC-ITS-2020-04Data about mobility provides information to improve city planning, identify traffic patterns, detect traffic jams, and route vehicles around them. This data often contains proprietary and personal information that companies and individuals do not wish others to know, for competitive and personal reasons. This sets up a paradox: the data needs to be analyzed, but it cannot be without revealing information that must be kept secret. A solution is to sanitize the data\u2014i.e., remove or suppress the sensitive information. The goal of sanitization is to protect sensitive information while enabling analyses of the data that will produce the same results as analyses of the unsanitized data. However, protecting information requires that sanitized data cannot be linked to data from other sources in a manner that leads to desanitization. This project reviews typical strategies used to sanitize datasets, the research on how some of these strategies are unsuccessful, and the questions that must be addressed to better understand the risks of desanitization

Modeling Bioenergy Supply Chains: Feedstocks Pretreatment, Integrated System Design under Uncertainty

Biofuels have been promoted by governmental policies for reducing fossil fuel dependency and greenhouse gas emissions, as well as facilitating regional economic growth. Comprehensive model analysis is needed to assess the economic and environmental impacts of developing bioenergy production systems. For cellulosic biofuel production and supply in particular, existing studies have not accounted for the inter-dependencies between multiple participating decision makers and simultaneously incorporated uncertainties and risks associated with the linked production systems. This dissertation presents a methodology that incorporates uncertainty element to the existing integrated modeling framework specifically designed for advanced biofuel production systems using dedicated energy crops as feedstock resources. The goal of the framework is to support the bioenergy industry for infrastructure and supply chain development. The framework is flexible to adapt to different topological network structures and decision scopes based on the modeling requirements, such as on capturing the interactions between the agricultural production system and the multi-refinery bioenergy supply chain system with regards to land allocation and crop adoption patterns, which is critical for estimating feedstock supply potentials for the bioenergy industry. The methodology is also particularly designed to incorporate system uncertainties by using stochastic programming models to improve the resilience of the optimized system design. The framework is used to construct model analyses in two case studies. The results of the California biomass supply model estimate that feedstock pretreatment via combined torrefaction and pelletization reduces delivered and transportation cost for long-distance biomass shipment by 5% and 15% respectively. The Pacific Northwest hardwood biofuels application integrates full-scaled supply chain infrastructure optimization with agricultural economic modeling and estimates that bio-jet fuels can be produced at costs between 4 to 5 dollars per gallon, and identifies areas suitable for simultaneously deploying a set of biorefineries using adopted poplar as the dedicated energy crop to produce biomass feedstocks. This application specifically incorporates system uncertainties in the crop market and provides an optimal system design solution with over 17% improvement in expected total profit compared to its corresponding deterministic model

Fuels and Fuel Technologies for Powering 21st Century Passenger and Freight Rail: Simulation-Based Case Studies in a U.S. Context

The last century brought a shift in rail propulsion from the (typically) coal-powered steam engine to a combination of the diesel-electric locomotive and the electrified locomotive running under electrified overhead lines. While, no doubt, an advance over the earlier technology, the two incumbent technologies are not without their shortcomings. In the current era, rapid technological developments and increased concerns about climate change have also spurred interest away from the internal combustion engine and the use of fossil fuels in various applications. These same technologies hold promise in a rail context, a mode of transportation that relies on a smaller number of more centralized operators. With the tremendous investment of time, cost, and other resources that can go into a pilot experiment of a fuel technology and, often, related regulatory processes, it makes sense to determine the key candidates for such pilots. A major goal of this work is to help industry and government narrow down the key technologies, in terms of cost, viability, and environmental impacts, and simultaneously identify the challenges that may be encountered by a given technology that otherwise appears to hold significant promise. This study focuses on a U.S. context, and on the period between 2022 and 2038. Passenger and freight rail routes and systems were examined, each with different characteristics, via simulations of a single rail trip, A general environmental analysis was also performed on freight switcher locomotive activity. The fuels examined included diesel, natural gas, Fischer-Tropsch diesel, hydrogen, and, in a passenger rail and switcher context, diesel and hydrogen powertrains paired with batteries to take in regenerative braking energy. The study finds cost reductions with both natural gas and (natural gas-derived) Fischer-Tropsch diesel, but with limited environmental benefits. Hydrogen via fuel cell has significant promise to reduce GHG and criteria pollutant emissions. That technology\u2019s costs, both fuel and equipment, are highly uncertain; however, the study finds that, with lower bound projected costs, it could be competitive with diesel-electric costs; in the case of passenger rail, hybridization with batteries is also compelling. Hybridized hydrogen also was found to demonstrate a clear environmental benefit in switcher locomotive applications

Performance Assessment of Asphalt Mixes Containing Reclaimed Asphalt Pavement and Tire Rubber

The pavement community, including both agencies and industries, is moving toward more sustainable pavement designs and pavement network management. Increasing amounts of recycled materials, both reclaimed asphalt pavement (RAP) and recycled tire rubber, are expected to be used in new pavement construction projects in the future to reduce the use of virgin binder and aggregates. The main concern of using recycled materials in new asphalt pavement is the potential negative effect on the performance. Thus, the primary objective of this dissertation is to improve the current laboratory testing technologies and performance assessment approaches for characterizing the performance-related properties of asphalt mixes containing recycled materials and to improve understanding of how these properties affect the performance of asphalt pavements so that they can be designed and constructed better

The Reciprocal Relationship between Children and Young Adults\u2019 Travel Behavior and Their Travel Attitudes, Skills, and Norms

At a fundamental level, individuals require specific competencies to travel. These include skills, knowledge, attitudes, and norms, which together form the construct of travel \u201cmotility.\u201d Though the effects of possessing these basic travel competencies on travel behavior have been studied to varying degrees in isolation, motility has not been well studied as a cohesive unit nor as an outcome of interest. In this dissertation, I seek to understand how individuals\u2019 travel experiences build their motility. I examine two longitudinal panels, with schoolchildren in Davis, CA and with undergraduate students attending the University of California, Davis, both focusing on bicycling motility. I find that early bicycling behavior is associated with increased probability of possessing positive bicycling attitudes, a high level of bicycling skill, and perceptions of bicycling as a normal, acceptable mode of travel. In my third dissertation study, I investigate driving motility through a study of driver\u2019s licensing delay. Licensure relates to motility directly and indirectly: getting a driver\u2019s license directly increases motility, while not getting a driver\u2019s license may indirectly lead to increases in motility for non-driving modes, since teenagers without driver\u2019s licenses are likely to gain experiences bicycling, walking, or taking public transit. In recent decades, increasing numbers of American teenagers have chosen to delay or forego licensure; I study the factors that influence the decision to delay through a retrospective survey of students, staff, and faculty at the University of California, Davis. I find that graduated driver\u2019s licensing laws, walkable residential locations, and driver\u2019s licensing attitudes (which vary by generation) are associated with the timing of driver\u2019s licensing. Combined with the results of my other two studies, this suggests that the teenagers who choose to delay driver\u2019s licensing may gain valuable, motility-building experiences with sustainable alternative modes of travel

Simulating Life with Personally-Owned Autonomous Vehicles through a Naturalistic Experiment with Personal Drivers

UC-ITS-2018-09Forty-three households in the Sacramento region representing diverse demographics, modal preferences, mobility barriers, and weekly vehicle miles traveled (VMT) were provided personal chauffeurs for one or two weeks to simulate travel behavior with a personally-owned, fully autonomous vehicle (AV). During the chauffeur week(s), the total number of trips increased on average by 25 percent, 85 percent of which were \u201czero-occupancy\u201d (ZOV) trips (when the chauffeur is the only occupant). Average VMT for all households increased by 60 percent, over half of which came from ZOV trips. VMT increased most in households with mobility barriers and those with less auto-dependency but least in higher VMT households and families with children. Transit, ridehailing, biking, and walking trips dropped by 70 percent, 55 percent, 38 percent, and 10 percent, respectively. The results highlight how AVs can enhance mobility, but also adversely affect the transportation system