Army Concept for Space and Lightsat

This paper explains the Army\u27s role in space both now and in the future, and how space capabilities support joint Air/Land Battle doctrine across the full spectrum of conflict. It concludes with a focus on the Army\u27s requirements for the use of lightsats

Benefits, Costs, and Financing of Truck-Only Highway Lanes

As increasing amounts of intercity freight are transported by trucking firms, the possibility of constructing truck-only lanes along selected rural Interstate highways warrants consideration. On heavily traveled sections, there is potential for improvements in safety and productivity if such lanes were added. In this paper, we explore the conditions under which investment in truck-only lanes could be considered and what sorts of benefits may accrue to both occupants of passenger vehicles and to operators of heavy trucks. Then we examine the available evidence regarding the nature and magnitude of these benefits to gain insight into the willingness of highway users to pay for these lanes. We conclude that the willingness to pay for truck-only lanes on the part of occupants of passenger vehicles appear to be quite limited and that support for these lanes on the part of trucking firms is likely to depend upon their being allowed to operate longer-combination vehicles (LCVs) on them. Trucking firms could be assessed tolls to travel in truck-only lanes, with these tolls representing some fraction of the increased productivity gained through being allowed to operate LCVs. Finally, we pose several questions that would need to be answered before an investment in truck-only lanes might be considered along a given Interstate segment

Highway Performance and Time-Sensitive Industries

Communities and states are using every means available to them to attract and retain economic activity. One such strategy is to plan for the changing needs of new and existing businesses. In the past two decades, firms have come to view time as one of their most precious resources. Some businesses have adopted efficiently timed production methods like just-in-time, in which inventory and safety stock are minimized; deliveries of intermediate goods at all stages of production are synchronized with suppliers so that at no point do products linger. Highway projects that reduce unanticipated delays enhance the ability of time sensitive businesses to maintain closely timed production and sales schedules. Perhaps the most important type of delay in this context is that produced by incidents, which are events that disrupt normal traffic flow. In addition to accidents, incidents include stalled vehicles, debris on the road, or other impediments to orderly flow. While they are rare events, incidents do happen, and they can greatly affect travel times, especially on roads operating at near capacity. Highway improvements can reduce the likelihood of incidents and reduce the severity of impacts when incidents do occur. How to measure increases in highway system performance for time-sensitive businesses when these systems are upgraded is a focus of this monograph. We begin by examining the changes in the business environment that precipitated the movement toward time-sensitive production. Then, from an extensive survey, we conclude that although businesses in Iowa are somewhat less time-sensitive than businesses in many other places, Iowa’s businesses anticipate tighter production schedules in the future. We show how traffic incidents and incident-produced congestion erode highway performance for time-sensitive industries. An analysis of the causes and consequences of incident-produced delays provides the foundation for our model of incident-produced delay, which we have developed to gauge highway performance for time-sensitive firms. This research was a joint effort between researchers at the University of Iowa Public Policy Center and Iowa State University’s Department of Transportation and Logistics. The Iowa Department of Transportation provided funding for this project

Multicriteria evaluation on accessibility-based transportation equity in road network design problem

This paper investigates the performance of accessibility-based equity measurements in transportation and proposes a multiobjective optimization model to simulate the trade-offs between equity maximization and cost minimization of network construction. The equity is defined as the spatial distribution of accessibilities across zone areas. Six representative indicators were formulated, including GINI coefficient, Theil index, mean log deviation, relative mean deviation, coefficient of variation, and Atkinson index, and incorporated into an equity maximization model to evaluate the performance sensitivity. A bilevel multiobjective optimization model was proposed to obtain the Pareto-optimal solutions for link capacity enhancement in a stochastic road network design problem. A numerical analysis using the Sioux Falls data was implemented. Results verified that the equity indicators are quite sensitive to the pattern of network scenarios in the sense that the level of equity varies according to the amount of overall capacity enhancement as well as the assignment of improved link segments. The suggested multiobjective model that enables representing the Pareto-optimal solutions can provide multiple options in the decision making of road network design.</p

Forecasting environmental equity: Air quality responses to road user charging in Leeds, UK

Sustainable development requires that the goals of economic development, environmental protection and social justice are considered collectively when formulating development strategies. In the context of planning sustainable transport systems, trade-offs between the economy and the environment, and between the economy and social justice have received considerable attention. In contrast, much less attention has been paid to environmental equity, the trade-off between environmental and social justice goals, a significant omission given the growing attention to environmental justice by policy makers in the EU and elsewhere. In many countries, considerable effort has been made to develop clean transport systems by using, for example, technical, economic and planning instruments. However, little effort has been made to understand the distributive and environmental justice implications of these measures. This paper investigates the relationship between urban air quality (as NO2) and social deprivation for the city of Leeds, UK. Through application of a series of linked dynamic models of traffic simulation and assignment, vehicle emission, and pollutant dispersion, the environmental equity implications of a series of urban transport strategies, including road user cordon and distance based charging, road network development, and emission control, are assessed. Results indicate a significant degree of environmental inequity exists in Leeds. Analysis of the transport strategies indicates that this inequity will be reduced through natural fleet renewal, and, perhaps contrary to expectations, road user charging is also capable of promoting environmental equity. The environmental equity response is however, sensitive to road pricing scheme design

The future role of Scottish local government economic development

Since 1979 local authorities have been subjected to two main pressures from central government: increasing control over the range and type of services that can be provided; and greater emphasis on the private sector's role. So far, beyond being affected by the general financial constraints that local government has been placed under, the economic development services that many local authorities provide have escaped largely unscathed. This situation seems now likely to change radically as a result of three measures. These are:- a) the Local Government and Housing Bill; b) Scottish Enterprise; and c) changes to the structure of local government. When considered in isolation these measures contain much that is attractive and which could produce a more effective economic development service; for example, a specific power to carry out economic development and the creation of an integrated training and enterprise development service. However the argument that is put forward in this paper is that these measures have to be seen as complementary. They are part of an overall strategy intended to result in a major reduction in local government's local economic development activities

Network Centrality of Metro Systems

Whilst being hailed as the remedy to the world’s ills, cities will need to adapt in the 21st century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no “winner takes all”) unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities

The Boundaries of Justice: The Challenges of Environmental Justice Assessments for Transportation Projects

Over recent decades, federal guidelines for transportation projects have required increasing attention to impacts on communities. Executive Order 12898 requires federal agencies to conduct environmental justice (EJ) assessments to determine if negative effects from projects will fall disproportionately on minority or low-income populations. Yet transportation agencies have not given specific guidance on the method for conducting such assessments. Therefore practitioners and researchers apply a variety of analytical techniques. This paper uses a case study of a planned road widening project in Daytona Beach, Florida, to compare the various methods currently used in EJ assessments. The choice of reference area and of method for determining the decision threshold for a finding of disproportionality are shown to have important implications for the outcome of an assessment. Because the spatial distribution of racial/ethnic and low-income groups will vary widely from place to place, practitioners and transportation agencies should not decide on the precise method, but carefully consider the characteristics and distribution of the data being used and select the method that most fairly represents the data distribution. Conducting genuine EJ assessments is not only required by federal regulations, but can head off conflicts, better reveal the true costs of projects, and allow for more equitable distribution of costs and benefits by better targeting mitigation efforts. Thus rather than shying away from EJ assessments, transportation agencies and practitioners should continue to explore methods and approaches.Master of City and Regional Plannin