The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.
This Low-Volume Roads Engineering Best Management Practices Field Guide is intended to provide an overview of the key planning, location, design, construction, and maintenance aspects of roads that can cause adverse environmental impacts and to list key ways to prevent those impacts. Best Management Practices are general techniques or design practices that, when applied and adapted to fit site-specific conditions, will prevent or reduce pollution and maintain water quality. BMPs for roads have been developed by many agencies since roads often have a major adverse impact on water quality, and most of those impacts are preventable with good engineering and management practices. Roads that are not well planned or located, not properly designed or constructed, not well maintained, or not made with durable materials often have negative effects on water quality and the environment.
When accidents happen, drivers are blamed for the mishap. When drivers consistently fail at certain locations, it then becomes obvious that the problem lies not with them, but with the geometry of the road itself. Because accidents are not evenly distributed throughout the road network, locations with high accident rates are a clear indication that there are other factors involved, besides driver error, which are characterized by the road itself. In most countries, two-lane rural roads make up about 90 percent of rural networks and they account for over 60 percent of highway fatalities worldwide, approximately 500,000 people per year. The methodology described in this book will support the achievement of quantified measures of: design consistency; operating speed consistency; and, driving dynamic consistency. The safety criteria are then combined into an overall safety module for a simplified general overview of the safety evaluation process. The authors also encourage the coordination of safety concerns with important economic, environmental and aesthetic considerations. This book will be an invaluable aid to educators, students, consultants, highway engineers and administrators, as well as scientists in the fields of highway design and traffic safety engineering.
Research indicates that up to 28% of crashes are due to the road environment. The most important objective of road safety audit is to minimize crashes, and to minimize the severity of any crashes that may occur on a new road project. The series of CAREC road safety engineering manuals came from the endorsement of the CAREC Road Safety Strategy 2017–2030 by member countries. The strategy supports and encourages CAREC authorities to plan, design, construct, and maintain safe roads. This manual also explains the road safety audit process as it can apply in CAREC road projects. It provides information about the audit process for those who undertake the audits (practitioners) and for those who manage the audit process (policy makers).
Road asset management is one of the top priorities of the Central Asia Regional Economic Cooperation (CAREC) Transport and Trade Facilitation Strategy 2020. The implementation of performance-based road maintenance contracts (PBCs)—an essential element of road asset management—promotes effective and efficient maintenance of road networks. Well-designed PBCs keep roads in predefined good condition at relatively low cost. This guide aims to help policy makers in CAREC member countries understand and implement PBCs. After a brief history of the development of PBCs, it discusses the various types of PBCs and their relative advantages and disadvantages. It highlights PBC implementation in selected developed, developing, and transitional countries, including CAREC member countries, to illustrate best practices.
"Since the publication of the first edition of the Access Management Manual, the context for transportation planning and roadway design in the United States has been transformed. Transportation agencies and local governments are under growing pressure to integrate land use and transportation policy and achieve a more sustainable, energy-efficient transportation system. This second edition of the manual responds to these developments by addressing access management comprehensively, as a critical part of network and land use planning. The content is interdisciplinary, with guidance pertinent to various levels of government as well as to pedestrians, bicyclists, and motorized vehicles, including trucks and buses, and is strongly grounded in decades of research, engineering science, and professional experience. Greater emphasis is placed on appropriate location of access, and guidance is refined to provide appropriate consideration of context and community issues. Substantial updates aid state and local agencies in managing access to corridor development effectively. Specific guidance on network and circulation planning and modal considerations is included, as well as guidance on effective site access and circulation design. A chapter on corridor management reinforces these concepts with a framework for application of access management in different contexts, along with appropriate strategies for each context. There are also new chapters on network planning, regional access management policies and programs, interchange area access management, auxiliary lane warrants and design, and right-of-way and access control. The manual concludes with an extensive menu of access management techniques and information on their application"--Provided by publisher.
