tailieunhanh - Assessing and Managing the Ecological Impacts of Paved Roads

There are 4 million miles of roads in the United States. One hundred years ago, roads were primarily unpaved and had half the number of miles of the present . road system. As the system grew, roads became wider and more complex structurally to provide for more and heavier traffic. New construction technology and greater structural stability were needed to improve the road system. All phases of road development—from construction and use by vehicles to maintenance—affect physical and chemical soil conditions, water flow, and air and water quality. Roads alter habitats, increase wildlife mortality, and disperse nonnative pest species of plants and animals. At larger scales, roads affect wildlife migration. | Assessing and Managing the Ecological Impacts of Paved Roads Free Executive Summary http catalog Free Executive Summary Assessing and Managing the Ecological Impacts of Paved Roads Committee on Ecological Impacts of Road Density National Research Council ISBN 978-0-309-10088-5 324 pages 6 x 9 paperback 2005 This free executive summary is provided by the National Academies as part of our mission to educate the world on issues of science engineering and health. If you are interested in reading the full book please visit us online at http catalog . You may browse and search the full authoritative version for free you may also purchase a print or electronic version of the book. If you have questions or just want more information about the books published by the National Academies Press please contact our customer service department toll-free at 888-624-8373. All phases of road development from construction and use by vehicles to maintenance affect physical and chemical soil conditions water flow and air and water quality as well as plants and animals. Roads and traffic can alter wildlife habitat cause vehicle-related mortality impede animal migration and disperse nonnative pest species of plants and animals. Integrating environmental considerations into all phases of transportation is an important evolving process. The increasing awareness of environmental issues has made road development more complex and controversial. Over the past two decades the Federal Highway Administration and state transportation agencies have increasingly recognized the importance of the effects of transportation on the natural environment. This report provides guidance on ways to reconcile the different goals of road development and environmental conservation. It identifies the ecological effects of roads that can be evaluated in the planning design construction and maintenance of roads and offers several recommendations to help better understand