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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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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When the quality of service (QoS) of an unmanned air vehicle's (UAV) communications link is poor, and the UAV is tracking a moving target, a trade- off exists between the fidelity and timeliness of information provided from the vehicle to an operator. The authors' 2011 ICCRTS paper showed that an optimal representation scheme for transmitting information from UAV to operator can be found by using information theory. This paper extends that work by introducing an adaptive, autonomous UAV command and control system that autonomously changes the fidelity of information communicated to an operator in response to variances in communications QoS. Results and analysis of hardware-in-the-loop experiments using a UAV that is tracking a moving car are presented. The paper also examines the impact of information decay and network performance on both human tele-operation and on-board autonomous control, comparing the relative performance of tele-operation and autonomy as a function of entropic drag, which is a measurement, in information theory 'bits,' of the rate at which information is lost due to unpredictable changes in the environment. In the experiments described in this paper, entropic drag is produced by the movement of the vehicle being tracked.

关键词：汽车；空气系统；大气污染

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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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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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The objectives of this report are to quantify existing acoustical conditions in Vicksburg National Military Park (VICK) and provide results that can be used for park management and planning. Multiple external sound sources currently impact the soundscape of VICK, including Interstate 20, U.S. Highway 61, Kansas City Southern Railroad, Yazoo Diversion Canal (shipping traffic), and a harbor industrial complex. Inside the park, buses, RVs, motorcycles, and cars create noise along the 16-mile tour road and especially at the Visitor Center and U.S.S. Cairo parking areas. Mississippi Department of Transportation (MDOT) is planning to widen a section of I-20 immediately adjacent to the parks southeast border. MDOT has contracted out the noise analysis for this construction project to Neel-Schaffer, Inc. The company uses 15-minute point measurements and TNM modeling to quantify impacts, but park staff requested more detailed sound monitoring by the Natural Sounds and Night Skies Division.

关键词：汽车；交通安全；沟通系统

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Research has shown that an effective way to reduce impaired driving is to increase the perceived risk of being stopped and arrested by law enforcement if driving while impaired. One of the most successful strategies for doing this is the coupling of intense and highly visible enforcement with publicity about the enforcement campaign. The term high-visibility enforcement (HVE) is used to describe law enforcement efforts aimed at deterring unsafe driving behavior by increasing the public's perception of being caught, arrested, and prosecuted. Two common enforcement strategies of HVE operations are sobriety checkpoints and saturation patrols. Checkpoints concentrate law enforcement officers at the roadside to identify impaired drivers passing through. Saturation patrols involve an increased number of officers patrolling a limited area where impaired driving is prevalent. Both use highly visible elements (such as a concentration of law enforcement officers, bright lights, signs, and marked patrol cars) to heighten their visual impact. Enforcement efforts must be supported by an equal amount of publicity and communications.

关键词：汽车；事故减少；交通安全

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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 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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