المؤلفون: Wali, Behram, Frank, Lawrence D

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Built Environment and Design, Commerce, Management, Tourism and Services, Urban and Regional Planning, Prevention, Behavioral and Social Science, Clinical Research, Life on Land, Transportation and Freight Services, Logistics & Transportation, Urban and regional planning, Transportation, logistics and supply chains

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/3tm4t067Test

المؤلفون: Rezaei, Nazanin, Todd-Blick, Annika, Fujita, K Sydny, Popovich, Natalie, Needell, Zachary, Poliziani, Cristian, Caicedo, Juan David, Guirado, Carlos, Spurlock, C Anna

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Built Environment and Design, Commerce, Management, Tourism and Services, Urban and Regional Planning, Transportation and Freight Services, Human Geography, Logistics & Transportation, Urban and regional planning, Transportation, logistics and supply chains, Human geography

الوصف: We propose the Individual Experienced Utility-Based Synthesis (INEXUS) accessibility metric, which is developed to leverage an open-source agent-based regional transportation model. We include two specifications: the Potential INEXUS, which relates to an individual's potential set of mode alternatives and the Realized INEXUS, which reflects the optimal mode chosen by the agent. One advantage of using an agent-based approach is that it enables us to estimate individual agent-level behavior and travel needs. This addresses a commonly identified limitation of many existing accessibility metrics, which exhibit insensitivity to the heterogeneity of transportation preferences, opportunities, and constraints across subpopulations. While many system-level outcomes of interest may inform transportation planning, arguably an equally important consideration is that the system provides adequate and equitable access to goods and services for the broad spectrum of those traveling along its network. In many cases, average results do not reflect the experience of a majority – or even a significant – portion of the population. We apply our methods in a case study of alternative ridehail price scenarios to demonstrate the value of INEXUS distributions in evaluating differences in accessibility within and between population groups.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/1dr5z4bmTest

المؤلفون: Handy, Susan

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Engineering, Civil Engineering, Commerce, Management, Tourism and Services, Urban and Regional Planning, Transportation and Freight Services, Logistics & Transportation, Transportation, logistics and supply chains, Civil engineering

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/2ts440v3Test

المؤلفون: Venkataram, Prashanth S, Flynn, Justin A, Bhuiya, Musfiqur Rahman, Barajas, Jesus M, Handy, Susan

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Built Environment and Design, Commerce, Management, Tourism and Services, Urban and Regional Planning, Urban and regional planning, Transportation, logistics and supply chains

الوصف: We comprehensively review typical problems that people with disabilities face when using local transportation modes. We show how specific problems with each mode can affect many different disability subgroups at once and can affect or be affected by problems with other modes. Academic literature about transportation for adults with disabilities skews toward walking, driving one's own motor vehicle, using a ridehailing or taxi service, using a carsharing service as a driver, and using public transit, so this review focuses primarily but not exclusively on those modes. We frame these problems using the terms that we introduced in a previous work. Provider-view availability refers to where & when a transportation mode is present or legal to use. Immediate usability refers to features of a mode's vehicles or infrastructure, where and when such vehicles and infrastructure are present, that help or hurt a user. User-view availability captures how serious problems with immediate usability for some users can prevent them from using those modes at all, make some aspects of provider-view availability moot for them. Cumulative usability refers to problems with a mode that arise over frequent use, longer trips, or more complicated trips, that may discourage a user from using that mode. We explain how modes that have similar requirements, present or absent, for the user to drive or to make a first-/last-mile connection exhibit consequently similar problems with provider-view availability, immediate usability, user-view availability, and cumulative usability.

الوصول الحر: https://escholarship.org/uc/item/7k33r75vTest

المؤلفون: Kuncheria, Anu, Walker, Joan L, Macfarlane, Jane

المصدر: Transportation Letters. 15(10)

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Engineering, Civil Engineering, Commerce, Management, Tourism and Services, Sustainable Cities and Communities, vehicle routing, neighborhood impacts, traffic impact analysis, route choice, large scale urban simulation, city evaluation, Transportation, logistics and supply chains, Civil engineering

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/75n03323Test

المؤلفون: Venkataram, Prashanth S, Flynn, Justin A, Bhuiya, Musfiqur Rahman, Barajas, Jesus M, Handy, Susan

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Built Environment and Design, Commerce, Management, Tourism and Services, Urban and Regional Planning, Disability, Accessibility, Policy, Mobility, Proximity, Urban and regional planning, Transportation, logistics and supply chains

الوصف: Transportation planning researchers use the term “accessibility” to characterize the ability of people to reach jobs, school, healthcare and other services and activities. Disability scholars use that term to characterize the ability of people with disabilities to use transportation modes where and when present. In the United States of America (US), transportation policymakers’ use of the latter definition only for minimal legal compliance at the expense of the former definition, without synthesizing both definitions, has led to real-world negative consequences for transportation for people with disabilities, including when new train lines lead to consolidation of bus routes and in regulatory debates about how ridehailing services may serve people with disabilities. Thus, in the context of transportation policy, we propose a new set of terms that, when used consistently, can more accurately distinguish these concepts. These terms are “provider-view availability”, referring to where & when a transportation mode is present or legal to use, “immediate usability”, referring to the ease of interacting with a vehicle or (physical or digital) infrastructure upon encountering it, “user-view availability”, referring to how some people cannot start trips on a given mode due to severe problems with immediate usability, and “cumulative usability”, referring to the challenges that users of a certain mode may face more often as trip times or distances increase. We argue that transportation policymakers in the US could more accurately characterize holistic problems with transportation facing people with disabilities by consistently using these terms and thereby mitigate similar negative consequences going forward.

الوصول الحر: https://escholarship.org/uc/item/1tg0g954Test

المؤلفون: Xu, Xiaodan, Yang, Hung-Chia, Jeong, Kyungsoo, Bui, William, Ravulaparthy, Srinath, Laarabi, Haitam, Needell, Zachary A, Spurlock, C Anna

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Built Environment and Design, Commerce, Management, Tourism and Services, Urban and Regional Planning

الوصف: Understanding and forecasting complex freight mode choice behavior under various industry, policy, and technology contexts is essential for freight planning and policymaking. Numerous models have been developed to provide insights into freight mode selection; most use discrete choice models such as multinomial logit (MNL) models. However, logit models often rely on linear specifications of independent variables despite potential nonlinear relationships in the data. A common challenge for researchers is the absence of a heuristic and efficient method to discern and define these complex relationships in logit model specifications. This often results in models that might be deficient in both predictive power and interpretability. To bridge this gap, we develop an MNL model for freight mode choice using the insights from machine learning (ML) models. ML models can better capture the nonlinear nature of many decision-making processes, and recent advances in “explainable AI” have greatly improved their interpretability. We showcase how interpretable ML methods help enhance the performance of MNL models and deepen our understanding of freight mode choice. Specifically, we apply SHapley Additive exPlanations (SHAP) to identify influential features and complex relationships to improve the MNL model’s performance. We evaluate this approach through a case study for Austin, Texas, where SHAP results reveal multiple important nonlinear relationships. Incorporating those relationships into MNL model specifications improves the interpretability and accuracy of the MNL model. Findings from this study can be used to guide freight planning and inform policymakers about how key factors affect freight decision-making.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/0qr0917sTest

المؤلفون: BAIK, BOK, EVEN‐TOV, OMRI, HAN, RUSSELL, PARK, DAVID

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Commerce, Management, Tourism and Services, Peace, Justice and Strong Institutions, real effects, Dodd-Frank Act, conflict minerals disclosures, nonfinancial disclosure, corporate social responsibility, responsible sourcing, ESG, due diligence, supply chain, resource curse, Accounting, Auditing and Accountability, Banking, Finance and Investment, Accounting, Accounting, auditing and accountability, Banking, finance and investment

الوصف: ABSTRACT: Section 1502 of the Dodd–Frank Act requires SEC‐registered issuers to conduct supply chain due diligence and submit conflict minerals disclosures (CMDs) that indicate whether their products contain tantalum, tin, tungsten, or gold (3TG) sourced from the Democratic Republic of the Congo (DRC) or its neighboring countries (“covered countries”). Consistent with the reputational cost hypothesis, we find that heightened public attention to CMDs increases responsible sourcing. After Section 1502 takes effect, we find higher demand for 3TG products processed in certified smelters, decreased conflicts in covered countries’ mining regions relative to other regions, and reduced sensitivity of conflict risk to conflict minerals’ price spikes. Finally, we find that conflicts decrease in Eastern DRC territories with prevalent 3T (tantalum, tin, and tungsten) mines but increase in territories with prevalent gold mines. Overall, our findings highlight the real effects of enhanced supply chain transparency regulation.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/4c41h659Test

المؤلفون: Garber, Michael D, Watkins, Kari E, Flanders, W Dana, Kramer, Michael R, Lobelo, RL Felipe, Mooney, Stephen J, Ederer, David J, McCullough, Lauren E

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Health Sciences, Commerce, Management, Tourism and Services, Life on Land, Bicycle infrastructure, Strava, Case-control studies, Bicycling safety, Atlanta, Georgia, Causal inference, Public Health and Health Services, Urban and Regional Planning, Transportation and Freight Services, Urban and regional planning, Transportation, logistics and supply chains, Public health

الوصف: Bicycling has individual and collective health benefits. Safety concerns are a deterrent to bicycling. Incomplete data on bicycling volumes has limited epidemiologic research investigating safety impacts of bicycle infrastructure, such as protected bike lanes. In this case-control study, set in Atlanta, Georgia, USA between 2016-10-01 and 2018-08-31, we estimated the incidence rate of police-reported crashes between bicyclists and motor vehicles (n = 124) on several types of infrastructure (off-street paved trails, protected bike lanes, buffered bike lanes, conventional bike lanes, and sharrows) per distance ridden and per intersection entered. To estimate underlying bicycling (the control series), we used a sample of high-resolution bicycling data from Strava, an app, combined with data from 15 on-the-ground bicycle counters to adjust for possible selection bias in the Strava data. We used model-based standardization to estimate effects of treatment on the treated. After adjustment for selection bias and confounding, estimated ratio effects on segments (excluding intersections) with protected bike lanes (incidence rate ratio [IRR] = 0.5 [95% confidence interval: 0.0, 2.5]) and buffered bike lanes (IRR = 0 [0,0]) were below 1, but were above 1 on conventional bike lanes (IRR = 2.8 [1.2, 6.0]) and near null on sharrows (IRR = 1.1 [0.2, 2.9]). Per intersection entry, estimated ratio effects were above 1 for entries originating from protected bike lanes (incidence proportion ratio [IPR] = 3.0 [0.0, 10.8]), buffered bike lanes (IPR = 16.2 [0.0, 53.1]), and conventional bike lanes (IPR = 3.2 [1.8, 6.0]), and were near 1 and below 1, respectively, for those originating from sharrows (IPR = 0.9 [0.2, 2.1]) and off-street paved trails (IPR = 0.7 [0.0, 2.9]). Protected bike lanes and buffered bike lanes had estimated protective effects on segments between intersections but estimated harmful effects at intersections. Conventional bike lanes had estimated harmful effects along segments and at intersections.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/3v24n6chTest

المؤلفون: Borup, Rod L, Weber, Adam Z, Myers, Deborah J, Neyerlin, KC, Kusoglu, Ahmet, Ahluwalia, Rajesh, Mukundan, Rangachary, Cullen, David A, Spendelow, Jacob S, Kleen, Gregory

المصدر: ECS Meeting Abstracts, vol MA2023-02. (37)

مصطلحات موضوعية: Transportation, Logistics and Supply Chains, Engineering, Civil Engineering, Commerce, Management, Tourism and Services, Affordable and Clean Energy

الوصف: While significant advances have been made and early commercial fuel cell light-duty vehicles (LDVs) are starting to be produced, fuel cells in the heavy-duty-vehicle (HDV) transportation sector (including trucks, long-haul semitrailers, maritime, trains, etc.) are nascent, despite the fact that advantages of fuel cells compared to both diesel and electric powertrains are very compelling in terms of emissions, charging time, efficiency, power-to-weight ratio, among others. However, the fuel-cell technology for HDVs requires a paradigm shift in fuel-cell research and development compared to LDVs, where the emphasis becomes efficiency and improvements in durability instead of a focus on increased power densities and lower cell costs. Heavy-duty applications require significantly longer vehicle lifetimes (>25,000 hours/1,000,000 miles for heavy-duty trucks), and therefore require improved fuel cell durability compared to light-duty vehicles. In 2020, HFTO formed the Million Mile Fuel Cell Truck Consortium (M2FCT) that includes a core team of five national laboratories to overcome durability and efficiency challenges in PEMFCs for heavy-duty applications with an initial focus on long-haul trucks. While targets and testing protocols have been developed for light-duty vehicles, the same level of targets and testing protocols have not been established for heavy-duty transportation. With operational times of greater than > 25,000 hours required, the need for well-developed accelerated stress tests (ASTs) is amplified. Results from these ASTs demonstrate the need for more durable electrode layers and well-controlled potential variations. This presentation will provide an overview of the DOE’s Fuel Cell R&D approach, highlighting past and current activities, as well as strategies to enable fuel cell competiveness for heavy-duty applications. Acknowledgments This work was funded through the DOE M2FCT Consortium with thanks to DOE EERE HFTO, Fuel Cell Technologies Office. Team Leader: Dimitrios Papageoropoulos and Technical Development Manager: Greg Kleen.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/0b60p9p4Test