This thesis examines the vehicle design and sales mix changes necessary to double the average fuel economy of new U.S. cars and light-trucks by model year 2035. To achieve this factor of two target, three technology options that are available and can be implemented on a large scale are evaluated: (1) channeling future vehicle technical efficiency improvements to reducing fuel consumption rather than improving vehicle performance, (2) increasing the market share of diesel, turbocharged gasoline and hybrid electric gasoline propulsion systems, and (3) reducing vehicle weight and size.The illustrative scenarios demonstrate the challenges of this factor-of-two improvement --major changes in all these three options would need to be implemented before the target is met. Over the next three decades, consumers will have to accept little further improvements in acceleration performance, a large fraction of new light-duty vehicles sold must be propelled by alternative powertrains, and vehicle weight must be reduced by 20-35% from today. The additional cost of achieving this factor-of-two target would be about 20% more than a baseline scenario where fuel consumption does not change from today's values, although these additional costs would be recouped within 4 to 5 years from the resulting fuel savings.Thus, while it is technically feasible to halve the fuel consumption of new vehicles in 2035, aggressive changes are needed and additional costs will be incurred. Results from this study imply that continuing the current trend of ever increasing performance and size will have to be reversed if significantly lower vehicle fuel consumption is to be achieved.
Transportation officials are increasingly faced with challenging decisions about how to design, plan, and manage infrastructure to confront changes in climate and extreme weather events. An understanding of which impacts affect infrastructure and at what point damage begins to occur is a critical step toward assessing overall vulnerability and risk. However, few resources exist to help managers and designers identify key thresholds and indicators of sensitivity to weather and climate impacts. This paper introduces a sensitivity matrix, a tool developed for the U.S. Department of Transportation's Gulf Coast Study, Phase 2, adaptation pilot project in Mobile, Alabama. This matrix is an important step toward a more comprehensive understanding of relationships between climate and transportation. Transportation planners can use this matrix to screen for assets that are particularly sensitive and, therefore, potentially vulnerable to climate change. Where possible, the matrix includes key thresholds at which damage may be observed. This resource can assist the transportation community in conducting climate vulnerability and risk assessments. This sensitivity matrix reveals three main conclusions about the sensitivity of the transportation system to climate stressors. First, transportation assets tend to be more sensitive to extreme events than to incremental changes in the mean of climate variables. Second, services such as maintenance, traffic conveyance, and safety often are more sensitive to climate stressors than are physical assets. Finally, an asset is often sensitive to stressors whose occurrence is relatively unlikely in comparison with typical weather variability.
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