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Traffic Congestion (traffic + congestion)
Selected AbstractsAn environment for prosperity and quality living accommodating growth in the Thames ValleyCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 1 2004Hugh Howes The Thames Valley is seen as the powerhouse of the British economy, and one of the best performing regions in Europe. This economic base offers opportunities for expansion with the potential for it to become the knowledge capital of Europe. Business interests view the area as a highly desirable location, not only because of its markets, skills and proximity to the City and Heathrow but also because of its high quality environment. Companies, however, complain of skills shortages, traffic congestion, lack of suitable premises and housing that is affordable to the workforce. Much of the Thames Valley is either Green Belt or Areas of Outstanding Natural Beauty. Furthermore, the availability of future water supplies, the maintenance of the quality of water in the rivers and managing flood risk are also likely to act as constraints on development in the future. How economic growth is to be achieved with minimal additional development and without detriment to the environment is the central question that is likely to dominate planning in the this region over the next few years. Is it possible to achieve more with existing resources? Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment. [source] Hybrid adaptive predictive control for a dynamic pickup and delivery problem including traffic congestionINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2008Cristián E. Cortés Abstract This paper presents a hybrid adaptive predictive control approach to incorporate future information regarding unknown demand and expected traffic conditions, in the context of a dynamic pickup and delivery problem with fixed fleet size. As the routing problem is dynamic, several stochastic effects have to be considered within the analytical expression of the dispatcher assignment decision objective function. This paper is focused on two issues: one is the extra cost associated with potential rerouting arising from unknown requests in the future, and the other is the potential uncertainty in travel time coming from non-recurrent traffic congestion from unexpected incidents. These effects are incorporated explicitly in the objective function of the hybrid predictive controller. In fact, the proposed predictive control strategy is based on a multivariable model that includes both discrete/integer and continuous variables. The vehicle load and the sequence of stops correspond to the discrete/integer variable, adding the vehicle position as an indicator of the traffic congestion conditions. The strategy is analyzed under two scenarios. The first one considers a predictable congestion obtained using historical data (off-line method) requiring a predictive model of velocities distributed over zones. The second scenario that accepts unpredictable congestion events generates a more complex problem that is managed by using both fault detection and isolation and fuzzy fault-tolerant control approaches. Results validating these approaches are presented through a simulated numerical example. Copyright © 2007 John Wiley & Sons, Ltd. [source] Characterization and comparison of traffic flow on reversible roadwaysJOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2010Laurence Lambert Abstract Reversible traffic operations have become an increasingly popular strategy for mitigating traffic congestion associated with the directionally unbalanced traffic flows that are a routine part of peak commute periods, planned special events, and emergency evacuations. It is interesting that despite its widespread and long-term use, relatively little is known about the operational characteristics of this form of operation. For example, the capacity of a reversed lane has been estimated by some to be equal to that of a normal lane while others have theorized it to be half of this value. Without accurate estimates of reversible lane performance it is not possible to confidently gauge the benefits of reversible roadways or model them using traffic simulation. This paper presents the results of a study to measure and evaluate the speed and flow characteristics of reverse-flow traffic streams by comparing them under various operating conditions and locations. It was found that, contrary to some opinions, the flow characteristics of reverse-flowing lanes were generally similar to normally flowing lanes under a variety of traffic volume, time-of-day, location, and type-of-use conditions. The study also revealed that drivers will readily use reversible lanes without diminished operating speeds, particularly as volumes increase. Copyright © 2010 John Wiley & Sons, Ltd. [source] Analysis of travel patterns between road and transit-oriented development areasJOURNAL OF ADVANCED TRANSPORTATION, Issue 1 2010Seungjae Lee Abstract The objectives of this study are to analyze the travel patterns based on social changes between 1996 and 2002, and then to identify main implications in transport policies in the Seoul Metropolitan Area (SMA). In SMA, there are many changes during 6 years. For example, SMA has changed the paradigm of transportation policy from car-oriented policy to public-oriented policy. So, this study examines the general travel pattern changes in the SMA and compares the travel patterns of regions invested in road construction (road-invested areas) with those of regions invested in transit (transit-invested areas). Study results show that while road investment had little effect on reducing congestion, the number of cars decreased in transit-invested areas due to the modal shift to transit modes. This study suggests that transit-oriented policies should be utilized as a solution to overcome severe traffic congestion. Copyright © 2010 John Wiley & Sons, Ltd. [source] Observing freeway ramp merging phenomena in congested trafficJOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2007Majid Sarvi This work conducts a comprehensive investigation of traffic behavior and characteristics during freeway ramp merging under congested traffic conditions. On the Tokyo Metropolitan Expressway, traffic congestion frequently occurs at merging bottleneck sections, especially during heavy traffic demand. The Tokyo Metropolitan Expressway public corporation, generally applies different empirical strategies to increase the flow rate and decrease the accident rate at the merging sections. However, these strategies do not rely either on any behavioral characteristics of the merging traffic or on the geometric design of the merging segments. There have been only a few research publications concerned with traffic behavior and characteristics in these situations. Therefore, a three-year study is undertaken to investigate traffic behavior and characteristics during the merging process under congested situations. Extensive traffic data capturing a wide range of traffic and geometric information were collected using detectors, videotaping, and surveys at eight interchanges in Tokyo Metropolitan Expressway. Maximum discharged flow rate from the head of the queue at merging sections in conjunction with traffic and geometric characteristics were analyzed. In addition, lane changing maneuver with respect to the freeway and ramp traffic behaviors were examined. It is believed that this study provides a thorough understanding of the freeway ramp merging dynamics. In addition, it forms a comprehensive database for the development and implementation of congestion management techniques at merging sections utilizing Intelligent Transportation System. [source] Towards statistical multicriteria decision modelling: a first approachJOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 6 2002Yves De Smet Abstract Many real life situations result from decisions taken by a very large number of decision makers. Among them, we may cite road traffic congestion, crowding during shopping, equity market behaviour, distribution of holiday destinations, etc. Furthermore, these decisions often depend on the optimisation of several conflicting criteria. In this paper, we introduce a new multicriteria tool based on Markov chains to model and manage these macroscopic phenomena. Finally, the road traffic congestion problem will be considered to illustrate the applicability of our approach. Copyright © 2003 John Wiley & Sons, Ltd. [source] Employers as Mediating Institutions for Public Policy: The Case of Commute Options ProgramsPOLICY STUDIES JOURNAL, Issue 4 2005Leisha DeHart-Davis Scholars have recently noted the role that employers can play as "mediating institutions" for public policy. Mediating institutions connect the private lives of individuals with public policy concerns by communicating societal norms to members and providing social contexts that encourage a commitment to these norms. Despite the potential importance of employers as mediating institutions for public policy, little scholarly attention has been devoted to employer mediation behavior. Accordingly, this study examines two research questions. What factors influence an employer's willingness to mediate policy problems? And how effective are employers as mediating institutions? The mediation behaviors of interest relate to employer efforts to mitigate traffic congestion and air quality problems by enabling employee "commute options," which are alternatives to single-occupancy vehicle commuting to work. Drawing on theories of organization behavior, the study hypothesizes that self-interest, organizational control, and association membership will affect willingness to provide commute options. The study also hypothesizes that employers providing commute options will have lower percentages of employees that drive to work alone. Both sets of hypotheses are supported by statistical analyses of data from a cross-sectional mail survey of metropolitan Atlanta organizations. [source] THE 200 KM CITY: BRISBANE, THE GOLD COAST, AND SUNSHINE COASTAUSTRALIAN ECONOMIC HISTORY REVIEW, Issue 1 2009Peter Spearritt Brisbane; infrastructure; Southeast Queensland; traffic; urban planning Since the 1970s, several Southeast Queensland coastal towns in areas marketed as the ,Gold Coast' and the ,Sunshine Coast' have merged with each other and joined with Brisbane to become one of the world's longest urban coastal strips. The population of this 200 km long city is fast approaching three million. This urban pattern reflects the preferences of many Australians about where and in what type of housing they would like to live. The unplanned nature of this growth raises several policy challenges relating to resource use and traffic congestion. [source] | |||||||||||||