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路边/中央分隔带护栏的能量吸收器的使用评价
Several types of elastomeric energy absorbers were evaluated for use in a Manual for Assessing Safety Hardware (MASH) Test Level 4 (TL-4) energy-absorbing, urban roadside/median barrier. Twelve dynamic bogie tests were conducted on 60- and 80-durometer EPDM rubber cylinders. Five dynamic bogie tests were conducted on marine shear fenders. One dynamic test was conducted on a 27-ft (8.2-m) long installation of 2-in. (51-mm) thick EPDM rubber cylinders spaced at 8 ft (2.4 m) on center and attached to the front face of a 32-in. (813-mm) tall, concrete New Jersey-shaped barrier with a continuous 6-in. x 12-in. (152-mm x 305-mm) steel tubular front rail. One dynamic test was conducted on a 28-ft (8.5-m) long installation of 11.-in. (295-mm) tall marine shear fender posts spaced at 8 ft (2.4 m) on center with a 6.-in. (171-mm) tall, upper timber rail. Both barrier concepts showed promising results. Several static tests were conducted on the marine shear fenders at hot, cold, and room temperatures to evaluate its effect on energy-absorber behavior.
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改善我们对公路拥堵和定价如何影响旅游需求的理解
Driver response to congestion and road pricing is an essential element to forecasting the future use of roadway systems and estimating the effect that pricing has on demand and route choice. Though many studies have been conducted in the past and revenue studies are routinely done for proposed toll roads, there is still a need for improving the behavioral basis for forecast. The objective of this project was to develop mathematical descriptions of the full range of highway user behavioral responses to congestion, travel time reliability, and pricing. These descriptions were achieved by mining existing data sets. The report estimates a series of nine utility equations, progressively adding variables of interest. This research explores the effect on demand and route choice of demographic characteristics, car occupancy, value of travel time, value of travel time reliability, situational variability, and an observed toll aversion bias. The primary audience for this research is professionals who develop travel demand and traffic forecasts. Policy makers may also have an interest in the behavioral findings that could have policy implications. Equations for commercial drivers were not developed since their routes are normally determined, in part, by contracts and company policies.
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交通部门的节能策略
Transit administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem.This study describes how transit agencies are reducing energy use and is based on survey responses from 51 diverse agencies across the country, a literature review of a variety of academic and professional publications, and case examples of four agencies.
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交通运输领域智能系统介绍
Urban mobility is not only one of the pillars of modern economic systems, but also a key issue in the quest for equality of opportunity, once it can improve access to other services. Currently, however, there are a number of negative issues related to traffic, especially in mega-cities, such as economical issues (cost of opportunity caused by delays), environmental (externalities related to emissions of pollutants), and social (traffic accidents). Solutions to these issues are more and more closely tied to information and communication technology. Indeed, a search in the technical literature (using the keyword "urban traffic" to filter out articles on data network traffic) retrieved the following number of articles (as of December 3, 2013): 9,443 (ACM Digital Library), 26,054 (Scopus), and 1,730,000 (Google Scholar). Moreover, articles listed in the ACM query relate to conferences as diverse as MobiCom, CHI, PADS, and AAMAS. This means that there is a big and diverse community of computer scientists and computer engineers who tackle research that is connected to the development of intelligent traffic and transportation systems. It is also possible to see that this community is growing, and that research projects are getting more and more interdisciplinary.
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增加损坏驾驶执法能见度:六个案例研究
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.