A Funding Compromise Can Set Transportation on Path Towards Sustainability [Policy Brief]

DTRT13-G-UTC29A number of proposals have sought to address aspects of securing or reforming state and federal transportation funding. This policy brief summarizes findings from a white paper that assembles the most prominent of these proposals and reviews them in the context of sustainable transportation: funding sustainability, environmental sustainability, and social justice. Taken together, these strategies would set transportation on the path toward sustainability

Steel Reinforcement Section Loss Guidance Tables

(c) 1003320 (wo) 12The strength and durability of reinforced concrete (RC) bridges are adversely affected by the deterioration of their structural members. When investigating bridges in need of maintenance and repair, the deterioration due to the corrosion of steel rebars is commonly found to be a primary source of structural damage and degradation. To ensure the safety and performance of RC bridges while reducing their direct and indirect costs, an accurate estimate of the extent of reinforcement section loss has central importance for a wide spectrum of engineers and decision-making authorities. This research project investigated the steps required to achieve such rebar section loss estimates. To achieve this purpose, field assessments of rebar section loss were correlated with available predictive models and later calibrated to condition-specific field data. The outcome, which has been delivered in the form of steel reinforcement section loss guidance tables, directly contributes to understanding variability in rebar section loss when making loss predictions for use in structural evaluation. This facilitates planning preventive and/or corrective actions tailored to the condition state of deteriorating bridge elements

Laboratory and Field Evaluation of a Composite Glued-Laminated Girder to Deck Connection

Buchanan County, Iowa, has been working with the National Center for Wood Transportation Structures and a timber fabricator to develop the next-generation timber bridge. The goal is to increase the structural efficiency of timber bridges and increase longevity by (1) creating a composite deck-girder system and (2) using an epoxy overlay. These design elements have the potential to increase viable bridge options for use not only on Iowa\u2019s roadways, but nationally and internationally as well. The bridge system developed for this research was a composite glue-laminated (glulam) girder-deck system utilizing epoxy for the connection and an epoxy overlay wearing surface on the deck. This design was investigated through small- and large-scale laboratory testing of the composite epoxy connection and a field demonstration bridge built utilizing this girder to deck connection detail and epoxy overlay. The small-scale tests showed that the best overall joint connection is an epoxy and lag bolt connection. The joints with epoxy at least tripled the shear capacity of the lag bolt joint, and addition of mechanical fasteners to the epoxy connection marginally increased performance. The large-scale laboratory tests showed a small increase in the load capacity and movement of the neutral axis when the deck panels are affixed to the girders, both of which indicate potential composite action. Furthermore, the epoxied connection exhibited an improved composite connection over the lag bolt connection. Three live load tests on the field demonstration bridge in 2015, 2016, and 2017 indicated that transverse load distribution for all load cases was adequate. The composite action observed was not likely substantial enough to be accounted for in design. The chip seal shows signs of cracking at the transverse deck panel joints, but because of the epoxy the joints remain sealed and show no signs of moisture intrusion on the underside of the deck. The epoxy wearing surface on the deck performed better as an impermeable joint filler than a wearing surface

Reducing the Carbon Footprint of Heavy-Duty Trucks through Eco-Driving [Policy Brief]

DTRT13-G-UTC29This policy brief summarizes findings from a research report that examines the fuel-savings and GHG emissions impacts of various eco-driving practices

What to Make of Biofuels? Understanding the Market from 2010 to the Present, and Projecting Ahead to 2030 Given Current Policies [Policy Brief]

A research team at the University of California, Davis examined the track record of the past decade for clues as to why this happened, and looked forward to 2030 to point to how current policies are likely to still fall short in delivering low-carbon biofuels that can reach scales needed for these hard-to-decarbonize sectors. The findings highlight barriers to low-carbon biofuel development that would safeguard against unintended consequences such as additional emissions from land use changes or higher food prices that can come from competition with the use of crops for fuel. This policy brief summarizes the findings from that research and provides policy implications

Results of the 2014-2015 Campus Travel Survey

The UC Davis Campus Travel Survey is a joint effort by the Transportation & Parking Services (TAPS) and the Sustainable Transportation Center, part of the Institute of Transportation Studies at UC Davis. Since 2007 the survey has been administered 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 carbon emissions. Over the past seven years, the travel survey results have been used to assess awareness and utilization of campus transportation services and estimate demand for new services designed to promote sustainable commuting at UC Davis. Data from the campus travel survey have also provided researchers with valuable insights about the effects of attitudes and perceptions of mobility options on commute mode choice. This year\u2019s survey is the eighth administration of the campus travel survey. The 2014-15 survey was administered online in October 2014, distributed by email to a stratified random sample of 30,815 students, faculty, and staff (out of an estimated total population of 42,405). About 14 percent (4,224 individuals) of those contacted responded to this year\u2019s survey, with 11.4 percent actually completing it. For the statistics presented throughout this report, the authors weighed the responses by role (freshman, sophomore, junior, senior, Master\u2019s student, PhD student, faculty, and staff) and gender so that the proportion of respondents in each group reflects their proportion in the campus population

Results of the 2013-2014 Campus Travel Survey

The UC Davis Campus Travel Survey is a joint effort by the Transportation & Parking Services (TAPS) and the Sustainable Transportation Center, part of the Institute of Transportation Studies at UC Davis. Since 2007 the survey has been administered 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 carbon emissions. Over the past six years, the travel survey results have been used to assess awareness and utilization of campus transportation services and estimate demand for new services designed to promote sustainable commuting at UC Davis. Data from the campus travel survey have also provided researchers with valuable insights about the effects of attitudes and perceptions of mobility options on commute mode choice. This year\u2019s survey is the seventh administration of the campus travel survey. The 2013-14 survey was administered online in October 2013, distributed by email to a stratified random sample of 27,798 students, faculty, and staff (out of an estimated total population of 42,115). About 14.5 percent (4,025 individuals) of those contacted responded to this year\u2019s survey, with 13.2 percent actually completing it. For the statistics presented throughout this report, the authors weighed the responses by role (freshman, sophomore, junior, senior, Master\u2019s student, PhD student, faculty, and staff) and gender so that the proportion of respondents in each group reflects their proportion in the campus population

Freight Efficiency Strategies: Operational Modernization at Distribution Nodes

This White Paper concludes with recommendations that inform next steps in the development of the California Sustainable Freight Action Plan

A Funding Compromise Can Set Transportation on Path Towards Sustainability

DTRT13-G-UTC29A number of proposals in the past year have sought to address aspects of securing or reforming state and federal transportation funding. This white paper assembles the most prominent of these proposals and reviews them in the context of sustainable transportation: funding sustainability, environmental sustainability, and social justice. Funding recommendations include a one-time use of corporate taxes to allow states to reduce the backlog of maintenance needs. The federal gas tax would be continued and indexed to inflation. Greenhouse gas (GHG) reduction targets would be set for each state and states would be allowed to \u2018buy down\u2019 their gas tax as they reduce their GHG emissions. States would be given pricing and tolling authority and have the authority to implement a vehicle miles traveled (VMT) tax. States would also assume responsibility for all roads. Taken together, these strategies would set transportation on the path toward sustainability

From LOS to VMT: Repurposing Impact Fee Programs Since Adoption of SB 743

Caltrans 65A0686 Task Order 049 USDOT Grant 69A3551747114This white paper assesses how cities are modifying transportation impact fees in response to Senate Bill (SB) 743, adopted in 2013 to orient environmental review of transportation impacts of development projects and plans in California to support sustainable development. SB 743 and its implementing guidelines eliminated \u201clevel of service\u201d (LOS) standards for automobile traffic delay as an environmental impact to be addressed under the California Environmental Quality Act (CEQA), recommending instead that localities and other lead agencies responsible for CEQA review analyze, and if possible, mitigate impacts on vehicle miles traveled (VMT) instead. As cities proceed to implement SB 743, some are going further than the minimum required to analyze and mitigate for VMT at the development project level. Instead, they are also pursuing \u201cprogrammatic\u201d approaches, including altering citywide impact fees imposed on developers, to support more systematic analysis and mitigation than is possible at the project level alone. Based on public documents research and interviews with consultants and planners, this paper identifies three basic approaches that cities are taking to design impact fees in conjunction with their policy approaches for addressing SB 743: first, to design impact fee programs that fund VMT-reducing projects, but without employing a VMT \u201cnexus\u201d (the nexus is the basis for identifying impacts to be addressed by the program); second, to employ a VMT nexus for identifying facilities need and cost allocation; and third, to design a fee program that links to systematic CEQA-reviewed VMT analysis in the General Plan and/or other related CEQA-reviewed citywide policy documents. In this latter approach, cities may or may not design their fee program to fund VMT-reducing projects; indeed, this approach may help facilitate a more traditional, LOS-based fee program. This outcome can happen if a city analyzes VMT systematically for the General Plan, and then adopts a \u201cstatement of overriding considerations\u201d under CEQA, which allows for development projects to \u201ctier\u201d off the programmatic environmental review so as to avoid the need for conducting cumulative VMT impacts analysis. This approach may facilitate more systematic integration of VMT and LOS analysis at the citywide level, but it does not support SB 743 goals for supporting VMT-reducing projects and programs