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A brief summary of road traffic‐related elasticity estimates as reported in the international literature is given. An indication of the orders of magnitude of these elasticities is outlined and the variation in estimates commonly found is emphasized. The results of previous extensive surveys are collated, but a wider scope of traffic‐related research is provided by reviewing recent work and including research that has received less attention. A variety of elasticity measures related to car travel, car ownership, freight traffic and fuel demand are reported. Based on the review, some important themes underpinning the demand for road traffic are revealed.  相似文献   
2.
Historically, human systems integration (HSI) and other operational issues are not addressed during the science and technology (S&T) phase because the focus is on technology development. That view is to solve the "tough science" first, and the rest is simple application by a program office or operational forces. An imbalance between technology development efforts and total system performance considerations, e.g., total ownership cost, workload, manning, training, operational concept, skills, and human performance, leads to suboptimal solutions at best, and at worst prevents the technology's benefits from transitioning out of S&T at all. If HSI is not addressed during the S&T phase, the responsibility falls to the acquisition programs to ensure that operator, maintainer, and total system performance are optimized in the final design. By this point, cost and schedule constraints can make this prohibitive, limiting the options to either using a legacy system or accepting the technology with suboptimal performance and high life-cycle costs (because design problems lead to manpower, training, and human error problems). However, if the S&T community uses HSI in their technology readiness level evaluation criteria, the Department of Defense can reduce its out-year costs and recapitalize that funding to buy required weapons systems and platforms while still reaping the tactical benefits that a new technology offers.  相似文献   
3.
Abstract

Policymakers and analysts concerned with coastal issues often need economic value information to evaluate policies that affect beach recreation. This paper presents economic values associated with beach recreation in San Diego County generated from a recreation demand model that explains a beach user's choice of which beach to visit. These include estimates of the economic values of a beach day, beach closures, and beach amenities.  相似文献   
4.
With several successful cases world‐wide, bus rapid transit (BRT) has reemerged as a cost‐effective transportation alternative for urban mobility. Despite the resurgence of BRT, there is a world‐wide paucity of research examining its ability to spur and development. By estimating spatial hedonic price functions, the paper determines the extent to which access to BRT stations in Bogotá, Colombia, currently are capitalized into land values. Results suggest that for every 5 min of additional walking time to a BRT station, the rental price of a property decreases by between 6.8 and 9.3%, after controlling for structural characteristics, neighbourhood attributes and proximity to the BRT corridor. Evaluated at the average walking time to a BRT station, this effect translates into an elasticity of between ??0.16 and ??0.22. Although these estimates cannot be attributable directly to the presence of the BRT system because a cross‐sectional design is used, they suggest that the land market in Bogotá values access to BRT station locations.  相似文献   
5.
Beach erosion presents a hazard to coastal tourism facilities, which provide the main economic thrust for most Caribbean small islands (CSIs). Ad hoc approaches to addressing this problem have given way to the integrated coastal zone management (ICZM) approach, which recommends data collection, analysis of coastal processes, and assessment of impacts. UNESCO's Coast and Beach Stability in the Caribbean (COSALC) project has provided most CSIs with an opportunity to monitor their beaches and collect over 10 years of data. Research has been directed at integrating these data with geographic information systems (GIS) and other information technologies to develop a prototype beach analysis and management system (BAMS) for CSIs. This article presents the results of phase I development of this effort, which includes the development of tools for integrating spatial and non-spatial coastal data, estimating long-term beach erosion/accretion and sand volume change trends at individual beaches, identifying erosion-sensitive beaches, and mapping beach erosion hazards. The Southeast Peninsula, St. Kitts, is used as a case study to develop these tools and demonstrate system functionality.  相似文献   
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Stresses impacting the coastal zone in the Asia-Pacific region are briefly reviewed under the headings of sustainable coastal activities, coastal ecosystem management, community/resource interactions, coastal resource economics and sustainability, coastal area planning, and integrated coastal policies. Recent contributions on mitigation of these stresses are introduced, with emphasis on the Coastal Zone Asia-Pacific Conference, held in Bangkok, May 2002, where various innovative approaches to research, education, information sharing, and coastal policies aiming at improving the state of the coastal areas were presented. These include the roles of community in integrated coastal management; tools and planning for management of coastal areas; education program and capacity building; and the establishments of national and regional frameworks for integrated coastal management. As appropriate information and its transfer are critical to these processes, an analysis is presented of the content of the database on coastal projects in the region, highlighting areas of research interests, funding sources, and achievements. Another database on coastal ecosystems, currently under development, is presented as an example of the type of resource that can be expected to help advance our knowledge and ability to improve the management of coastal areas. Overall, these tools should allow us, given the political will, to improve the state of coastal areas.  相似文献   
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