1、 Harold E. Linnenkohl, President Commissioner Georgia Department of Transportation American Association of State Highway and Transportation Officials John Horsiey Executive Director September 2006 To recipients of the Roadside Design Guide: Chapter 6 Updafe Instructions Chapter 6 of the Roadside Des
2、ign Guide, entitled “Median Barriers,“ has been revised to include updated guidance on the use of median barrier. Additional changes to the chapter include a new section on High-Tension Cable Barrier Systems and guidance on the placement of cable barrier. Please replace the corresponding sections of
3、 the 2002 Third Edition of the Roadside Design Guide with the following pages to ensure that your edition is both accurate and current: + Front cover and spine + + Chapter 6 + Index Front Matter, including Table of Contents, List of Figures, and List of Tables The enclosed CD-ROM includes the entire
4、 Roadside Design Guide with the revised Front Matter, Chapter 6, and Index incorporated. To keep your Guide correct and up-to-date, please replace the CD-ROM that came with the 2002 Third Edition of the Roadside Design Guide with the enclosed CD-ROM. Executive Office: 444 N. Capitol St., N.W., Suite
5、 249, V=hinn+nn n r 7m*l a=“ CoanocC amarlea “PilllllywI!, Y.“. LWWW I Telephone (202) 624-5800 Telefax (202) 624-5806 www.transportation.org Roadside Design Guide www.transportation.org O 2006 by the American Association of State Highway and Transportation Officiais. All rights reserved. Printed in
6、 the United States of America. This book, or parts thereof, may not be reproduced in any form without written permission of the publishers. ISBN: 1-56051-349-7 Publication Code: RSDGCHP-3 Executive Committee 2005 - 2006 President: Harold Linnenkohl, Georgia Vice President: David Sprynczynatyk, North
7、 Dakota Secretary-Treasurer: Larry King, Pennsylvania REGIONAL REPRESENTAm REGION I Jim Capaldi, Rhode Island, One-Year Term Robert Flanagan, Maryland, Two-Year Term REGION II: Harold Linnenkohl, Georgia, One-Year Term Joe McInnes, Alabama, Two-Year Term REGION Iit Frank Busalacchi, Wisconsin, One-Y
8、ear Term Carol Molnau, Minnesota, Two-Year Term WION W. David Sprynczynatyk, Noah Dakota, One-Year Term Victor Mendez, Two-Year Term NON-VOTING MEMBERS Immediate Past President: John Njord, Utah Executive Director: John Horsley, Washington, DC iii Highway Subcommittee on Design 2006 Alabama, Don T.
9、Arkle, P. E. Steven E. Walker, P. E. Mark Neidhold Robert Campbell Mary Viparina Phillip L. McConnell, P. E. Charles D. Clements, P. E. Mark Leja, P. E. Kevin E. Hanley, P. E. Mithilesh “Mitch” Kumar Gary W. Meacham Arthur W. Gruhn Michael W. Lonergan James H. Norman Michael H. Simmons Michael E Bal
10、bierer James M. Satterield, IV District of Columbia, Kathleen Penney Zahra Dorriz Allen Miller Robert W. Greer Jim Mills, P. E. David OHagan, P. E. James “Ben” Buchan, P. E. Babs Abubakari, P. E. Brent Story, P. E. Gary C. P. Choy Julius Fronda Loren D. Thomas Damon Allen Alaska, Arizona, Arkansas,
11、California, Colorado, -_ - Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Chairman: Allen D. Biehler, Pennsylvania Secretary: Dwight A. Home, FHWA Vice Chairman: Robert L. Walters, Arkansas AASHTO Staff Liaison: Jim McDonnell, P. E. Illinois, Indiana, Michael Hine Gerald Mroczka, P. E. Jeff
12、 Clanton, P. E. Michael J. Kennerly David L. Little Deanna Maifield James O. Brewer, P. E. Richard G Adams, P. E. LaMonte C. Armstrong, P. E. David Kratt, P. E. Jeff D. Jasper, P. E. Robert D. Martin, P. E. Nicholas Kalivado, III, P. E. Lloyd E. Porta, Jr. Jerome A. Casey, P. E. Kirk G McClelland Ro
13、bert D. Douglass John Blundo, P. E. Stanley W. Wood, Jr. Mark A. Van Port Fleet, P. E. Mukhtar Thakur David Foster John B. Pickering, P. E. C. Keith Purvis, P. E. David B. Nichols Kathryn P. Harvey Paul R. Ferry Lesly Tribelhorn Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Mich
14、igan, Minnesota, Mississippi, Missouri, Montana, iv Nebraska, Don Turek Dawn Allyn James J. Knott Frank Csiga, Jr., P. E. Ruedy Edgington Rand Pollard, P. E. Paul K. Sinnott, P. E. Craig A. Green Kiran B. Pate1 Brian Strizki Gabriela Contreras- Apodaca Joe S. Garcia Dennis Valdez Philip J. Clark, P.
15、 E. Daniel D Angelo, P. E. Richard W. Lee, P. E. Jay A. Bennett, P. E. Deborah M. Barbour Art McMillian Mark Gaydos Cash Misel Dirk Gross Timothy McDonald Tim Tegeler Thomas J. Lauer R. Scott Christie, P. E. Brian D. Hare, P. E. Ariel Prez Jos E. Santana-Pimente1 J. Michael Bennett, P. E. Robert 1.
16、Pratt, P. E. John V. Walsh, P. E. Joel Gengler Joe J. Feller Jeff C. Jones Mark Holloran Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Puerto Rico, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermo
17、nt, Mark A. Marek James C. McMinimee Kevin Marshia, P. E. Scott Rogers Mohammed Mirshahi Barton A. Thrasher, P. E. Harold Peterfeso, P. E. FchardAlbin, P. E. Ken L. Smith, P. E., CVS Jason C. Foster Gregory Bailey Jerry H. Zogg, P. E. Paul P. Bercich Tony Laird viiginia, Washington, West Virginia, W
18、isconsin, Wyoming, U.S. DOT Member Federal Aviation Administration, Rick Marineili, P. E. Associate Member - Bridge, Port, and Toll New Jersey Turnpike Authority, Pennsylvania Turnpike Commission, Port Authority of New York and New Jersey, J. Lawrence Williams Barry L. Troup, P. E. Scott D. Murre11
19、Associate Member - Federal USDA Forest Service, Ellen G LaFayette Associate Member - International Alberta, Allan Kwan British Columbia, Richard Voyer Ontario, Joseph A. Bucik Saskatchewan, Sukhy Kent AASHTO Staff Liaison Jim McDonnell, P. E. V Task Force for Roadside Safety - 2006 Richard B. Albin
20、Mark C. Ayton Drew Boyce Ben Buchan Joe Bucik Bernie Clocksin Keith A. Cota (Chair) Dean Focke Gregg C. Fredrick Harry Lee James Joe Jones Rodney D. Lacy David L. Little Mark A. Marek Aurora Meza Richard D. Powers (Secretary) Steve Reeves Jiten Soneji James P. Tenaglia Steven Walker (Vice Chair) Ric
21、hard D. Wilder Randy Cannon Mack Christensen B. Patrick Collins E Daniel Davis Monique R. Evans Earle S. Freedman Charles A. Goessel Billy Hattaway Kenneth E Hurst N. Kent Israel Douglas E. McCIure Patrick L. McDaniel Arthur D. Perkins Ronald J. Seitz George J. Stelzmiller Nick Artimovich Ken E Kobe
22、tsky Charles E McDevitt James T. McDonnell Charles W. Niessner Harry Taylor Current Members Washington Ontario Delaware Georgia Ontario South Dakota New Hampshire Ohio Wyoming Mississippi Missouri Kansas Iowa Texas Texas FHWA Mississippi Delaware Pennsylvania Alabama New York Contributing Former Mem
23、bers South Carolina Utah Wyoming Arizona Ohio Maryland New Jersey Fionda Kansas Louisiana South Carolina Missouri New York Kansas North Dakota Advisors FHWA AASHTO FHWA AASHTO TRB/“Rp FHWA 1998 -Present 1999 - Present 2002 -Present 1999 -Present 1997 -Present 2003 - Present 1992 -Present 2004 -Prese
24、nt 2001 -Present 2001 -Present 2004 -Present 200 1 - Present 1992 - Present 1986 -Present 2001 -Present 1986 -Present 2002 - Present 2004 -Present 2001 -Present 1997 - Present 200 1 - Present 1998 - 2001 1998 - 2005 1996 - 200 1 1996 - 2003 2001 -2004 1998 - 2003 1985 -2002 1999-2001 1992 - 2001 199
25、8 -2005 1992 - 2003 1997 - 2004 1986-2001 1991 -2001 1994 - 2003 1998 - Present 1997 - Present 2000 - Present 2000 - Present 1986 - 2004 1986 - 2006 vi PREFACE The Roadside Design Guide is developed and maintained by the AASHTO Subcommittee on Design, Technical Committee for Roadside Safety. The gui
26、de presents a synthesis of current information and operating practices related to roadside safety and is written in dual units-metric and U.S. Customary units. The 2006 edition of the guide supersedes the 1996 AASHTO publication of the same name and includes an update to Chapter 6, “Median Barriers,
27、” which replaces Chapter 6 of the 2002 edition. In this guide, the roadside is defined as that area beyond the traveled way (driving lanes) and the shoulder (if any) of the roadway itself. Consequently, roadside delineation, shoulder surface treatments, and similar on- roadway safety features are no
28、t extensively discussed. While it is a readily accepted fact that safety can best be served by keeping motorists on the road, the focus of the guide is on safety treatments that minimize the likelihood of serious injuries when a driver runs off the road. A second noteworthy point is that this docume
29、nt is a guide. It is not a standard, nor is it a design policy. It is intended for use as a resource document from which individual highway agencies can develop standards and policies. While much of the material in the guide can be considered universal in its application, there are several recommend
30、ations that are subjective in nature and may need modification to fit local conditions. However, it is important that significant deviations from the guide be based on operational experience and objective analysis. To be consistent with AASHTOs A Policy on Geometric Design of Highways and Streets, d
31、esign speed is as the basic speed parameter to be used in this guide. However, since the design speed is often selected based on the most restrictive physical features found on a specific project, there may be a significant percent- age of a project length where that speed will be exceeded by a reas
32、onable and prudent driver. Conversely, there will be other instances where roadway conditions will prevent most motorists from driving as fast as the design speed. Because roadside safety design is intended to minimize the consequences of a motorist leaving the roadway inadvertently, the designer sh
33、ould consider the speed at which encroachments are most likely to occur when selecting an appropriate roadside design standard or feature. Design values are presented in this document in both metric and U.S. Customary units. The relationship between the metric and US. Customary values is neither an
34、exact (soft) conversion nor a completely rational- ized (hard) conversion. The metric values are those that would have been used had the guide been presented exclusively in metric units; the U.S. Customary values are those that would have been used if the guide had been presented exclusively in U.S.
35、 Customary units. Therefore, the user is advised to work entirely in one system and not to attempt to convert directly between the two. The reader is cautioned that roadside safety is a rapidly changing field of study, and changes in policy, criteria, and technology are certain to occur after this d
36、ocument is published. Efforts should be made to incor- porate the appropriate current design elements into the project development. Comments from users of this guide on suggested changes or modifications resulting from further developmental work or hands-on experi- ence are appreciated. All such com
37、ments should be addressed to the American Association of State Highway and Transportation Officials, Engineering Program, 444 North Capitol Street NW, Suite 249, Washington, DC 20001. Table of Contents PREFACE . vii LISTOFFIGURES xvii LIST OF TABLES . xxii CHAPTER 1: AN INTRODUCTION TO ROADSIDE SAFE
38、TY 1 .o 1.1 1.2 1.3 1.4 1.5 HISTORY OF ROADSIDE SAFETY 1-1 THE BENEFITS OF ROADSIDE SAFETY 1-1 THE FORGIVING ROADSIDE CONCEET 1-2 THE CONTENT AND FORMAT . 1-3 CRASHTESTING ROADSIDE SAFETY FEATURES AND APPURTENANCES 1-3 THE APPLICATION OF THIS GUIDE 1-4 CHAPTER 2: ROADSIDE SAFETY AND ECONOMICS 2.0 OV
39、ERVIEW . 2-1 2.1 BENEFITKOST ANALYSIS . 2-1 2.1.1 Encroachments 2-2 2.1.2 Roadside Geometry 2-2 2.1.3 Crash Costs 2-2 2.2 BENEFIT/COST ANALYSIS PROGRAMS . 2-2 CHAPTER3: ROADSIDE TOPOGRAPHYAND DRAINAGE FEATURES 3.0 3.1 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.4 OVERVIEW . 3-1 T
40、HE CLEAR ROADSIDE CONCEPT 3-1 ROADSIDE GEOMETRY . 3-2 Foreslopes 3-2 Backslopes . 3-8 Transverse Slopes . 3-8 Drainage Channels 3-10 Recoverable Foreslopes 3-13 Non-Recoverable Foreslopes . 3-13 Critical Foreslopes . 3-13 APPLICATION OF THE CLEAR-ZONE CONCEPT 3-11 Examples of Clear-Zone Application
41、on Variable Slopes 3-13 Clear-Zone Applications for Drainage Channels and Backslopes . 3-13 DRAINAGE FEATURES 3-14 ix 3.4.1 3.4.2 3.4.2.1 3.4.2.2 3.4.2.3 3.4.3 3.4.3.1 3.4.3.2 3.4.3.3 3.4.3.4 3.4.4 Curbs 3-14 Cross-Drainage Structures 3-15 Traversable Designs . 3-15 Extension of Structure . 3-17 Shi
42、elding 3-17 Parallel Drainage Features 3-17 Eliminate the Structure 3-17 Traversable Designs . 3-18 Relocate the Structure . 3-19 Shielding 3-19 Drop Inlets . 3-19 CHAPTER 4: SIGN. SIGNAL. AND LUMINAIRE SUPPORTS. UTILITY POLES. TREES. AND SIMILAR ROADSIDE FEATURES 4.0 4.1 4.2 4.3 4.3.1 4.3.2 4.3.3 4
43、.4 4.5 4.6 4.6.1 4.6.2 4.6.3 4.6.4 4.6.5 4.7 4.8 OVERVIEW . 4-1 ACCEPTANCE CRITJZRIAFOR BREAKAWAY SUPPORTS 4-2 DESIGN AND LOCATION CRITERIA FOR BREAKAWAY AND NON-BREAKAWAY SUPPORTS 4-2 SIGN SUPPORTS . 4-3 Overhead Signs 4-4 Large Roadside Signs 4-4 Small Roadside Signs 4-8 MULTIPLE POST SUPPORTS FOR
44、 SIGNS 4-10 BREAKAWAY LUMINAIRE SUPPORTS 4-10 SUPPORTS FOR TRAFFIC SIGNALS AND MISCELLANEOUS TRAFFIC SERVICE DEVICES 4-13 Traffic Signals 4-13 Motorist-Aid Callboxes . 4-13 Railroad Crossing Warning Devices 4-13 Fire Hydrants . 4-14 Mailbox Supports 4-14 UTEITYPOLES . 4-14 TREES . 4-15 CHAPTl3R 5 RO
45、ADSIDE BARRIERS 5.0 OVERVIEW . 5-1 5.1 PERFORMANCE REQUIREMENTS . 5.1 5.1.1 Current Crash Test Criteria 5-1 5.1.2 Barrier Classifications . 5-1 5.2 WARRANTS 5-2 5.2.1 Embankments . 5-2 5.2.2 Roadside Obstacles . 5-2 5.2.3 Bystanders. Pedestrians, and Bicyclists 5-3 5.2.4 Motorcycles and Barrier Desi
46、gn . 5-5 5.3 PERFORMANCE LEVEL SELECTION FACTORS . 5-8 X 5.4 5.4.1 5.4.1.1 5.4.1.2 5.4.1.3 5.4.1.4 5.4.1.5 5.4.1.6 5.4.1.6.1 5.4.1.6.2 5.4.1.6.3 5.4.1.7 5.4.1.8 5.4.1.9 5.4.1.10 5.4.2 5.4.3 5.5 5.5.1 5.5.2 5.5.3 5.5.4 5.5.5 5.5.6 5.5.6.1 5.5.6.2 5.5.6.3 5.5.6.4 5.5.7 5.5.8 5.6 5.6.1 5.6.2 5.6.2.1 5.
47、6.2.2 5.6.3 5.6.4 5.7 5.7.1 5.7.2 5.7.3 STRUCTURAL AND SAFETY CHARACTERISTICS OF ROADSIDE BARRZERS 5-8 Standard Sections of Roadside Barriers 5-9 Three-Strand Cable 5-9 W-Beam (Weak Post) 5-9 Ironwood Aesthetic Guardrail 5-12 Box Beam (Weak Post) 5-12 Blocked-Out W-Beam (Strong Post) 5-12 Blocked-Ou
48、t Thrie-Beams . 5-15 Blocked-Out Thrie-Beam (Wood Strong Post) 5-15 Blocked-Out Thrie-Beam (Steel Strong Post) 5-16 Modified Thrie-Beam . 5-16 Merritt Parkway Aesthetic Guardrail 5-17 Steel-Backed Timber Guardrail 5-18 Concrete Barriers . 5-18 Stone Masonry Wall/Precast Masonry Wall . 5-21 Long-Span
49、, Double-Nested Guardrail Systems . 5-23 Transition Designs 5-23 SELECTION GUIDELINES 5-23 Barrier Performance Capability . 5-23 Barrier Deflection Characteristics 5-24 Site Conditions 5-26 Compatibility 5-26 Life-Cycle Costs 5-26 Maintenance 5-26 Routine Maintenance 5-26 Crash Maintenance 5-26 Material and Storage Requirements . 5-26 Simplicity of Barrier Design 5-26 Aesthetic and Environmental Considerations . 5-27 Field Experience . 5-27 PLACEMENT RECOMMENDATIONS 5-27 Lateral Offset . 5-27 Terrain Effects 5-29 Curbs 5-29 Slope
