Existing research has identified transportation challenges that low-income workers face, including a spatial mismatch between suburban entry level-jobs and urban low-income workers. These studies rely on travel models and secondary data and thus may not capture the temporal or other constraints that low-income workers experience. To better understand mobility patterns and accessibility as experienced, this analysis considers commute choices and perceptions of accessibility. Findings are based on open-ended surveys with 50 low-income workers in New Orleans and its inner suburbs. According to a sizable share of respondents (40%), transportation problems do not preclude applying to jobs. Black and centrally located respondents most commonly did not perceive transportation as a limitation to job opportunities. On the other hand, many respondents did describe an inability to get to suburban job opportunities. Even when missed job opportunities were not reported, almost all respondents cited transportation problems for some locations or activities, especially shopping. Losing a functional automobile was a common reason to change commute mode after Hurricane Katrina, indicating that low-income workers may shift in and out of car ownership, as well change home and job locations. A few respondents mostly active mode users were highly satisfied with their journey to work. Interviewees most commonly desired increased frequency and reliability as critical transit improvements. The mixed findings on perceived job accessibility demonstrate the need to better integrate transportation and workforce research and policy. In addition, more transportation research work on perceptions and actual challenges is needed, including the role of time in workplace demands and physical accessibility. Finally, given dynamic auto ownership status, jobs, and residential patterns, longitudinal study is needed.

关键词：汽车；经验；安全

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The LRT system in Denver, Colorado, connects the downtown with neighborhoods to the North, but primarily stretches southwards, travelling in existing transportation corridors carrying freeways and a heavy rail system. Outside of the downtown areas, the siting of the LRT system alongside the rigid infrastructure that comprises the heavy rail system and the freeway systems severely inhibits pedestrian accessibility to the transit system. To help further understand how the level of accessibility varies across the system, a systematic pedestrian level-of-service index for each station within the system was created that takes into account the formal, as well as informal street networks. This inaccessibility is highly likely to limit the potential that this system may have to generate development near station located that is fully integrated with the LRT system. Primary data collected by surveying households across the metropolitan area revealed very little difference between car ownership rates and weekly VMT of survey respondents living within 12- mile of an LRT station and elsewhere in the metropolitan area. Differentiating between those station areas that were Park-and-Ride (that is, had a park-and-ride lot) versus Walk-and-Ride showed a more nuanced picture. Residents who live in Walk-and-Ride stations do have have lower VMT than those who live in Park-and-Ride station areas and those who do not live near an LRT station. This reinforces the fact that development needs to be more fully integrated with the LRT system in order to achieve some intended goals such as less dependence on automobiles.

关键词：汽车；交互；潜在贡献

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Bus Rapid Transit (BRT) is becoming one of the most popular transit services in the United States. BRT is a viable option for many cities and can offer commuters travel times comparable to those experienced in private cars. With about 100 miles of BRT service scheduled for deployment in future years, Utah Transit Authority (UTA) for the first time is facing questions related to BRT service. How will the service interact with private traffic. Will passengers accept unfamiliar features of the new service. We looked at the new BRT deployment in West Valley City, Salt Lake County, UT. Lacking BRT operational data from the field, but with a need to estimate operational challenges before the actual implementation, we used estimates generated from a microsimulation model. In addition, a series of surveys were conducted to gain feedback from the users of the BRT system. Results from the microsimulation runs show that the new BRT line leads to significant improvements of transit operations, with reductions of close to 20% in travel times and 40% in dwell times. An additional transit signal priority (TSP) feature is estimated to reduce travel times another 15%. The results showed that TSP has minor negative impact on side-street traffic and no impact or minor positive impact on main traffic. Results from the survey's show a high degree of acceptance of the new MAX buses among passengers and drivers. In short, the first BRT system in Utah can be qualified as another success story for the BRT systems in the United States.

关键词：汽车；环境保护；高速公路

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Hybrids, plug-in hybrids, and battery electrics are conservatively estimated to reach a 5 percent national car park by 2030. Drastic increases in the price of gasoline resulting from oil shocks or major shifts in national energy and environmental policy, however, may push Electric Vehicles (EV) quickly beyond this small share. Should such critical changes occur, EVs will be poised to move beyond their current niche to gain wider scale acceptance and integration into transportation and energy infrastructure. EV battery technology has not improved to the degree needed to achieve the same range mobility as conventionally fueled vehicles. Electric powertrain hybridization and incorporation of regenerative systems such as braking and flywheels are steadily, but only incrementally, improving EV fuel efficiency and range performance. New Corporate Average Fuel Economy (CAFE) regulations in the next decade may drive the light-weighting or downsizing of some vehicle categories to achieve more aggressive fuel economy requirements, especially absent a breakthrough in vehicle battery technology. Light-weighting for battery electrics may be critical. Studies indicate that if primary vehicle mass is reduced between 40-59 percent, battery size and cost may be cut by nearly half without reductions in performance.

关键词：汽车；安全；智能交通

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The goal of this proposal is to develop novel modeling techniques to infer individual activity patterns from the large scale cell phone datasets and taxi data from NYC. As such this research offers a paradigm shift from traditional transportation modeling by using large scale, disaggregate data and provides an unique perspective to understand the complex interactions among human behavior, urban environments and traffic patterns. Urban development shapes the transportation systems, it determines what kind of transportation system a city has, and what does it look like. As an important dynamic component in urban systems, activities of transportation systems in turn captures the dynamics of the entire urban systems and enhance of our knowledge about the complex urban systems. This will ultimately contribute to the improvement of level of service and policy making on transportation systems. Taxi as a transportation tool has its unique characteristics. It is capable of capturing urban movement patterns both spatially and temporally since they serve as real time probes in the network. Moreover, we are able to examine the pulse of the city, the gap between supply and demand, real time road congestions and even more. On the other hand, accurate estimation and prediction of urban link travel times are important for improving urban traffic operations and identifying key bottlenecks in the traffic network.

关键词：汽车；大规模数据集；GPS

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关键词：汽车；轻型汽车技术；二氧化碳排放

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Catalytic converters (CATCONs) are required by Federal law to be installed in nearly all gasoline- and diesel-fueled onroad vehicles used in the United States. About 85 percent of the light-duty vehicles and trucks manufactured worldwide are equipped with CATCONs (Ashok Kumar, Director, A1 Specialized Services & Supplies, Inc., written commun. July 10, 2012). These vehicles include buses, cars, light- and heavy-duty trucks, and motorcycles. Many offroad vehicles, such as trail bikes and all-terrain recreational vehicles, are also equipped with CATCONs, but offroad vehicles are not addressed in this paper (Manufacturers of Emission Controls Association, 2008). Portions of the CATCONs (called monoliths) are recycled for their platinum-group metal (PGM) content and for the value of the stainless steel they contain. The cerium contained in the monoliths, however, is disposed of along with the slag produced from the recycling process. Although there is some smelter capacity in the United States to treat the monoliths in order to recover the PGMs, a great percentage of monoliths is exported to Europe and South Africa for recycling, and a lesser amount is exported to Japan. There is presently no commercial-scale capacity in place domestically to recover cerium from the monoliths. Recycling of cerium or cerium compounds from the monoliths could help ensure against possible global supply shortages by increasing the amount that is available in the supply chain as well as the number and geographic distribution of the suppliers. It could also reduce the amount of material that goes into landfills.

关键词：汽车；催化转换器；铈元素

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Understanding the diverse PHEV purchase behaviors among prospective new car buyers is key for designing efficient and effective policies for promoting new energy vehicle technologies. The ORNL MA3T model developed for the U.S. Department of Energy is described and used to project PHEV purchase probabilities by different consumers. MA3T disaggregates the U.S. household vehicle market into 1458 consumer segments based on region, residential area, driver type, technology attitude, home charging availability and work charging availability and is calibrated to the EIA's Annual Energy Outlook. Simulation results from MA3T are used to identify the more likely PHEV buyers and provide explanations. It is observed that consumers who have home charging, drive more frequently and live in urban area are more likely to buy a PHEV. Early adopters are projected to be more likely PHEV buyers in the early market, but the PHEV purchase probability by the late majority consumer can increase over time when PHEV gradually becomes a familiar product.

关键词：汽车；插电式混合动力；市场分析

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The Hybrid III dummy is a common standard test device for automotive car crash and mine blast (shock) events, which is validated and accepted by the crash test community. The Hybrid III 50th percentile male Anthropomorphic Test Device is also required by STANAG 4569 for injury assessment for mine detonation tests. The Test Device for Human Occupant Restraint (THOR) 50th percentile male advanced crash dummy is a next generation anthropomorphic test device that incorporates significantly improved biofidelity in all major parts and has expanded injury assessment capabilities beyond its predecessors, including the Hybrid III Anthropomorphic Test Device. Comparative evaluation of THOR versus Hybrid III dummies will bring additional insight and understanding of THOR injury prediction capabilities and biofidelity, specifically for vertical shock and mine blast events.

关键词：汽车；冲击；对比分析

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The risk of motor vehicle crashes (MVCs) associated with on-the-job operation of motor vehicles or exposure to road traffic hazards affects millions of workers in the United States, and this risk cuts across all industries and occupations. MVCs are consistently the leading cause of worker fatalities, affecting workers who drive all types of motor vehicles during their work day . passenger cars, heavy trucks, fire apparatus, and many others. A wide variety of interventions may be applied to prevent work-related MVCs: administrative controls such as seat belt policies, distracted-driving policies, pre-trip vehicle checks, driver training, reduced travel, and fatigue management; and engineering controls such as more crashworthy vehicles, advanced driver assistance systems, or active safety systems. Questions remain as to which are the most effective interventions to protect workers from risks of work-related MVCs. Through strategic planning, research, collaborations with stakeholders, and communication of research results and prevention, the National Institute for Occupational Safety and Health (NIOSH) is working to ensure that recommended solutions to prevent work-related MVCs and resulting injuries are based on sound research and are clearly communicated to employers and workers. The NIOSH Center for Motor Vehicle Safety (CMVS) is the focal point for activities within the Institute that address this pressing occupational safety problem. The CMVS was designated in December 2010 to strengthen and sustain the Institute's research and prevention activities to reduce work-related motor vehicle crashes and resulting injuries. It is a 'virtual' Center through which researchers from across the Institute and external partners from government, non-governmental organizations (NGOs), academia, labor, and industry bring complementary expertise to identify crash risk factors, develop and evaluate workplace interventions to prevent crashes, and communicate the results to employers and other stakeholders. The NIOSH CMVS is guided by the vision that: All workers who are exposed to hazards of motor vehicle traffic while working have the highest possible levels of protection from the risk of motor vehicle crashes and resulting injuries. The primary purpose of the 5-year strategic plan for the NIOSH CMVS is to define the priority areas for research and prevention initiatives through 2018.

关键词：事故预防；环境暴露；风险；通信

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