8 research outputs found
Recommended from our members
Generalized Costs of Travel by Solo and Pooled Ridesourcing vs. Privately Owned Vehicles, and Policy Implications
The emergence of “3 Revolutions” in transportation (automation, electrification and shared mobility) presents a range of questions regarding how consumers will travel in the future, and under what conditions there may be rapid adoption of various services. These include individual on-demand taxi-style services, shared mobility in pooled services, and use of public transit, all with or without drivers. There is now enough data and estimates on the costs of these service combinations, and in some cases ridership data, to consider how consumers are making choices and could do so in the future as things evolve. This project involved: (a) reviewing existing literature and data on consumer mode and vehicle choice; (b) developing new “generalized cost” estimates that combine monetary and non-monetary (e.g., hedonic) components of travel choice, notably incorporating value of time; and (c) conducting a comparison of monetary and generalized trip cost for a range of trip types across travel options in the near term (2020) and longer term (2030-35). Three main travel options were considered: privately owned vehicles, ridesourced solo trips, and ridesourced pooled trips. Consideration of internal combustion vs. battery electric and, in the longer term, automated technology was also core to the analysis. The trips considered include urban and suburban types in the San Francisco metro area, using actual trip characteristics. The results suggest that in the near-term, solo ridesourcing is likely to be perceived as significantly more expensive (in terms of monetary and time costs) than pooled ridesourcing or solo private vehicle trips except for those with a very high value of time. Solo ridesourcing does better in dense, slow, urban trips than in faster suburban trips. In the longer term, with automated driverless vehicles, solo ridesourcing could become the cheapest mode for many travelers in a range of situations. This report includes an initial consideration of the implications of these policies for affecting travel choices, presumably to push choices toward pooled ridesourcing as a sustainable option. VMT-based pricing, pricing that could be adjusted with vehicle occupancy, and parking-related approaches are described. A large price signal might be needed to shift travel, given some of the differences in generalized cost found in this analysis
Recommended from our members
Green Charging of Electric Vehicles Under a Net-Zero Emissions Policy Transition in California
California has many aggressive climate policies, primarily aimed at individual sectors. This study explores untapped policy opportunities for interactions between sectors, specifically between the transportation and the electricity grid. As electric vehicles become more prevalent, their impact on the electricity grid is directly related to the aggregate patterns of vehicle charging. Even without vehicle-to-grid services, shifting of charging patterns can be a potentially important resource to alleviate issues such as renewable intermittency. This study compares, through modeling, projected emissions reductions from managed vs. unmanaged charging. The lion’s share of emissions reduction in the light-duty transportation sector in California will come from electrification, with a cumulative 1 billion tons of CO2 reduction through 2045. Decarbonization of the current grid leads to an additional savings of 125 million tons of CO2 over the same time-period. Potential state policies to exploit synergies between transportation electrification and grid decarbonization could reduce cumulative emissions by another 10 million tons of CO2. These policies include strategic deployment of charging infrastructure, pricing mechanisms, standardizing grid interaction protocols, and supporting grid infrastructure requirements
Recommended from our members
Generalized Costs of Travel by Solo and Pooled Ridesourcing vs. Privately Owned Vehicles, and Policy Implications
The emergence of “3 Revolutions” in transportation (automation, electrification and shared mobility) presents a range of questions regarding how consumers will travel in the future, and under what conditions there may be rapid adoption of various services. These include individual on-demand taxi-style services, shared mobility in pooled services, and use of public transit, all with or without drivers. There is now enough data and estimates on the costs of these service combinations, and in some cases ridership data, to consider how consumers are making choices and could do so in the future as things evolve. This project involved: (a) reviewing existing literature and data on consumer mode and vehicle choice; (b) developing new “generalized cost” estimates that combine monetary and non-monetary (e.g., hedonic) components of travel choice, notably incorporating value of time; and (c) conducting a comparison of monetary and generalized trip cost for a range of trip types across travel options in the near term (2020) and longer term (2030-35). Three main travel options were considered: privately owned vehicles, ridesourced solo trips, and ridesourced pooled trips. Consideration of internal combustion vs. battery electric and, in the longer term, automated technology was also core to the analysis. The trips considered include urban and suburban types in the San Francisco metro area, using actual trip characteristics. The results suggest that in the near-term, solo ridesourcing is likely to be perceived as significantly more expensive (in terms of monetary and time costs) than pooled ridesourcing or solo private vehicle trips except for those with a very high value of time. Solo ridesourcing does better in dense, slow, urban trips than in faster suburban trips. In the longer term, with automated driverless vehicles, solo ridesourcing could become the cheapest mode for many travelers in a range of situations. This report includes an initial consideration of the implications of these policies for affecting travel choices, presumably to push choices toward pooled ridesourcing as a sustainable option. VMT-based pricing, pricing that could be adjusted with vehicle occupancy, and parking-related approaches are described. A large price signal might be needed to shift travel, given some of the differences in generalized cost found in this analysis
Recommended from our members
State-of-the-Knowledge White Paper Series: How Zero-Emission Vehicle Incentives and Related Policies Affect the Market
How, and how effectively, different electric vehicle (EV) related policies will work is an immediate and important question for California as the state updates its EV policies. Adding urgency, Assembly Bill (AB) 615, which was signed by the Governor, requires the California Air Resources Board (CARB) to produce a report by December 2018 on related topics, in consultation with the University of California Institute of Transportation Studies (UC ITS). Senate Bill (SB) 498, also signed, also requires CARB reporting with somewhat different but overlapping topics. The need is to define the state of the research on policies to support EV deployment in a manner that is directly usable by California in updating policies. The specific need for CARB is material estimates of these factors (called out in AB 615): "impact of income caps, increased rebates for low-income consumers, and increased outreach on the electric vehicle market, as well as a quantification of emissions reductions attributable to the Clean Vehicle Rebate Project."This white paper is one in a series summarizing recent research findings for the state of California. The topic of the series is evaluating the important components of electric vehicle adoption and its effects. The goals of these white papers are to: 1. Synthesize the best published and on-going research available on each topic; 2. Highlight important research gaps and propose areas for future research; 3. Provide the reader with a framework for understanding the various dimensions of each topic; 4. Make a clear link between research findings and policy implications, if possible; and 5. Be accessible to an informed and interested, but non-technical audience
A Pilot Randomized Controlled Clinical Trial to Assess Tolerance and Efficacy of Navy Bean and Rice Bran Supplementation for Lowering Cholesterol in Children
Background: Navy beans and rice bran demonstrate efficacy to regulate serum cholesterol in hypercholesterolemic adults; however, the cardiovascular disease (CVD) protective properties of these foods in children are unknown and merit investigation. Objective: The objectives were to determine whether cooked navy bean powder (NBP) and/or heat-stabilized rice bran (RB) supplementation is tolerable, improves dietary fiber intake in children, and modulates lipid profiles. Methods: Children aged 8 to 13 years at risk for CVD due to abnormal lipids were recruited. Elevated cholesterol levels were defined as total cholesterol ≥180 mg/dL and high-density lipoprotein (HDL) <60 mg/dL; low-density lipoprotein (LDL) ≥100 mg/dL and HDL <60 mg/dL; or non-HDL >100 mg/dL and HDL <60 mg/dL. Participants completed a pilot 4-week, randomized controlled, 4-arm dietary intervention. They consumed study-provided muffins or a smoothie daily that included 0 g NBP or RB (control), 17.5 g NBP, 15 g RB, or a combination 9 g NBP + 8 g RB. Fasting blood was collected at baseline and week 4. Participants also completed 3-day food logs and gastrointestinal health questionnaires. Results: Thirty-eight children completed the trial (n = 9 control, n = 10 NBP, n = 9 RB, and n = 10 NBP + RB groups). Only 3 participants withdrew due to noncompliance of required food consumption. Participants in the intervention groups significantly increased intake of NBP and RB at week 4 (p≤.01). The NBP and NBP + RB groups increased total fiber intake from baseline to week 4 (p=.02 and p=<.01, respectively). HDL-cholesterol was higher in NBP-group participants compared to control at week 4 ( P = .02). Conclusion: Increasing NBP and/or RB intake is tolerable for children, and our findings suggest higher daily intakes are needed for a longer duration to induce favorable changes across multiple serum lipid parameters
Robotic-Assisted Total Knee Arthroplasty Can Increase Frequency of Achieving Target Limb Alignment in Primary Total Knee Arthroplasty for Preoperative Valgus Deformity
Background: Robotic-assisted total knee arthroplasty (rTKA) has been shown to reduce the number of alignment outliers and to improve component positioning compared to manual TKA (mTKA). The primary purpose of this investigation was to compare the frequency of achieving target postoperative limb alignment and component positioning for rTKA vs mTKA. Methods: A retrospective comparative study was performed on 250 patients undergoing primary TKA by 2 fellowship-trained arthroplasty surgeons. Surgeon A performed predominantly rTKA (103 cases) with the ROSA system (Zimmer Biomet, Warsaw, IN) and less frequently mTKA (44 cases) with conventional instrumentation. Surgeon B performed only mTKA (103 cases). Target limb alignment for surgeon A was 0° for all cases and for surgeon B was 2° varus for varus knees and 0° for valgus knees. Radiographic measurements were determined by 2 reviewers. Target zone was set at ± 2 degrees from the predefined target. Results: When comparing rTKA to mTKA performed by different surgeons, there were no differences in the percentage within the target zone (57.28% vs 53.40%, P = .575), but rTKA did result in a greater percentage for cases with preoperative valgus (71.42% vs 44.12%, P = .031). Patient-reported Outcomes Measurement Information System Global-10 physical scores were statistically higher at both 3 (P = .016) and 6 months (P = .001) postoperatively for rTKA compared to mTKA performed by different surgeons. Conclusions: Although experienced surgeons can achieve target limb alignment correction with similar frequency when comparing rTKA to mTKA for all cases, rTKA may achieve target limb alignment with more accuracy for preoperative valgus deformity. Level of Evidence: Retrospective Cohort Study, Level III
Book of Abstracts: 2019 Health Equity Summer Research Summit Organized by the Center of Excellence in Health Equity, Training and Research, Baylor College of Medicine, Houston, Texas 77030, USA on June 18th, 2019
Copyright © 2020 Harris. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited