Category HIGHWAY ENGINEERING HANDBOOK

The Highway Engineering Handbook has been developed by knowledgeable engineers to serve as a comprehensive reference source for those involved in highway design. This handbook is broad in scope, presenting information on topics ranging from environmental issues to value engineering, from the design of culverts, lighting, and noise walls to the design of safety systems, retaining walls, and bridges. In addition, such fundamental subjects as location and pavement design are fully discussed.

This volume should be useful to a wide range of personnel involved in highway design and construction, including consulting engineers; engineers employed by departments of transportation in federal, state, and local governments; those involved with turnpike authorities; and engineering educators. Both experienced practitioners and serious students will find the information presented here useful and easy to apply. It should enable the engineer to create a design that fulfills the requirements of the highway user: a safe, smooth, durable, aesthetically pleasing, environmentally sensitive, and economical highway system.

Contributors to this handbook are experienced highway engineers, consultants, or educators. They are leading authorities in their subject areas. The guiding principle of this book is to present practical information that has direct application to situations encountered in the field. Efforts were made to coordinate the information with that of the American Association of State Highway and Transportation Officials (AASHTO). Metric units are used where feasible to ease the transition to that system.

The material in this book follows a logical sequence. It begins with a discussion of environmental issues, a fundamental consideration in modern highway design. This is followed by a chapter on location, design, and traffic that includes extensive examples of typical standard treatments. A subject critical to building and maintaining durable systems, pavement design and rehabilitation, is then presented. Following this, aspects of bridge engineering are discussed to aid in the selection of bridge type and material for a durable design. The essentials of culvert design are then offered, as well as information on the various culvert types available. Next, a discussion of roadway safety addresses the latest options for providing for errant vehicles that leave the traveled way. A wealth of information follows on signing and lighting highways, subjects that also are closely related to highway safety. A comprehensive chapter next addresses the selection and design of retaining walls and considers both generic and proprietary systems. Walls to reduce traffic noise and screen unsightly areas are then considered. Finally, a chapter on value engineering and life cycle cost presents fundamental insights into these areas, as well as application examples, to encourage cost-effective design.

The contributors and editors are indebted to their colleagues and a variety of sources for the information presented. Credit is given in references throughout the text to the extent feasible.

The reader is cautioned that independent professional judgment must be exercised when information given in this handbook is applied. Anyone making use of this information assumes all liability arising from such use.

Roger L. Brockenbrough, P. E.

Kenneth J. Boedecker, Jr., P. E.

FACTORS FOR CONVERSION TO SI UNITS OF MEASUREMENT

This new edition of the handbook has been updated throughout to reflect continuing changes and improvements in design trends and specifications. The chapter on bridge engineering has been revised to provide more comprehensive treatment of this important topic. The chapter on culverts and drainage provides updated hydraulic design information as well as the latest approved methods for the structural design of concrete, steel, and plastic pipes. The chapter on retaining walls has been expanded with new information on mechanically stabilized earth walls, including a section on bridge abutment walls. Significant new information has been added to the chapter on value engineering to reflect the current roles of the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Engineers (AASHTO); additional examples of applications have been included, too.

Regrettably, this edition of the handbook marks the passing of Kenneth Boedecker, a friend and colleague active in highway engineering applications for many years. His contributions, particularly in the development of improved specifications for drainage pipe and other products, are gratefully acknowledged.

Finally, the reader is cautioned that independent professional judgment must be exercised when information set forth in this handbook is applied. Anyone making use of this information assumes all liability arising from such use. Readers are encouraged to use the latest edition of the referenced specifications, because they provide more complete information and are subject to frequent change.

Roger L. Brockenbrough, P. E.

Improvements in highway design methods and practices are reflected in this Third Edition of the handbook. The chapter on environmental issues has been updated throughout in view of ever-evolving regulations in that area. The chapter on highway design includes information from the latest AASHTO “Green Book.” The trend to replace bridges with spans up to about 60 ft (18 m) with stiffened special long-span corrugated steel and precast concrete drainage structures is documented in the chapter on culverts. The chapter on safety systems shows the trend to use median barriers over wider median widths than in the past. Metric units have been added throughout the text and in tables and figures wherever feasible.

The reader is cautioned that independent professional judgment must be exercised when information set forth in this handbook is applied. Anyone making use of this information assumes all liability arising from such use. Readers are encouraged to use the latest edition of referenced specifications and guides, because they provide more complete information and are subject to frequent change.

Roger L. Brockenbrough, P. E.