1、ROADSIDEDESIGNGUIDE4thEdition 2011 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.American Association of State Highway and Transportation Officials444 North Capitol Street, NW, Suite 249Washington, DC
2、20001202-624-5800 phone/202-624-5806 faxwww.transportation.org 2011 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law. Cover photographs courtesy of Washington DOT and Missouri DOT.Publication Code: RSDG-4 ISB
3、N: 978-1-56051-509-8 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.Executive Committee 20102011OfficersPresident: Susan Martinovich, P.E., NEvADAvice President: Kirk Steudle, P.E., MiCHigANSecretary/Tr
4、easurer: Carlos Braceras, Utahimmediate Past President: VacantRegional RepresentativesREGION Igeorge N. Campbell, Jr., NEW HAMPSHirEBeverley K. Swaim-Staley, MArylANDREGION IIMike Hancock, KENTuCKyrobert St. Onge, SOuTH CArOliNAREGION IIIThomas K. Sorel, MiNNESOTAVacantREGION IVAmadeo Saenz, Jr., TE
5、xASFrancis g. Ziegler P.E., NOrTH DAKOTANon-Voting MembersExecutive Director: John Horsley, AASHTO 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.ivTask Force for Roadside SafetyRegion 1Delaware Drew Bo
6、yceMaryland Teri SoosNew Hampshire Keith A. Cota (Chair)New york richard D. WilderRegion 2Alabama Steven Walker (vice-Chair)georgia Ben BuchanMississippi Steve reeveslouisiana Paul FossierRegion 3iowa David littleKansas rod lacyMissouri Joe JonesOhio Michael BlineRegion 4idaho Damon AllenSouth Dakot
7、a Bernie ClocksinTexas Aurora (rory) MezaCalifornia Kevin HerrittSubcommittee on Bridges and Structures Representativesregion 1: Jiten K. Soneji, Delawareregion 2: vacantregion 3: vacantregion 4: vacantOthersFHWA Nick Artimovich (Secretary), Frank Julian, Ken Opiela, richard AlbinTrB Charles Niessne
8、rOntario Joe Bucik, Mark AytonAASHTO liaison Keith M. Platte 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.vHighway Subcommittee on DesignvACANT, ChairriCHArD lAND, California, vice ChairDAviD A. NiCHO
9、l, FHWA, SecretaryKEiTH M. PlATTE, AASHTO, Staff liaisonAlABAMA, William Adams, rex Bush, Carey KelleyAlASKA, Mark Neidhold, robert A. Campbell AriZONA, Mary viparina ArKANSAS, Michael Fugett, Phillip l. McConnellCAliFOrNiA, Terry l. Abbott COlOrADO, Jeffrey Wassenaar CONNECTiCuT, Michael W. lonerga
10、n, James H. Norman, Timothy M. WilsonDElAWArE, Michael F. Balbierer, James M. Satterfield DiSTriCT OF COluMBiA, Said Cherifi, Zahra Dorriz, Allen Miller FlOriDA, James Mills, David OHagan, Frank SullivangEOrgiA, James “Ben” Buchan, russell McMurry, Brent StoryHAWAii, Julius FrondaiDAHO, loren D. Tho
11、mas, Nestor FernandezilliNOiS, Scott E. StittiNDiANA, Jeff Clanton, Merril E. Dougherty, John E. Wright iOWA, Michael J. Kennerly, David l. little, Deanna Maifield KANSAS, James O. Brewer, robert lacyKENTuCKy, Keith Caudill, Bradley S. Eldridge, Jeff D. Jasper lOuiSiANA, Nicholas Kalivoda iii, David
12、 S. Smith, Chad WinchesterMAiNE, Bradford P. Foley MArylAND, Kirk g. McClelland MASSACHuSETTS, Stanley Wood, Jr.MiCHigAN, Bradley C. WieferichMiNNESOTA, John M. Chiglo, Mukhtar ThakurMiSSiSSiPPi, John M. reese, Amy Mood, C. Keith PurvisMiSSOuri, David B. Nichols, Kathryn P. Harvey MONTANA, Paul r. F
13、erry, lesly TribelhornNEBrASKA, James J. Knott, Ted WatsonNEvADA, Paul Frost, Eric glick, Paul K. SinnottNEW HAMPSHirE, Craig A. green NEW JErSEy, richard JaffeNEW MExiCO, gabriela Contreras-Apodaca, Joe S. garciaNEW yOrK, Daniel DAngeloNOrTH CArOliNA, Deborah M. Barbour, Jay A. Bennett, Art McMilla
14、n NOrTH DAKOTA, roger Weigel OHiO, Dirk gross, Timothy McDonaldOKlAHOMA, Tim Tegeler OrEgON, David Joe Polly, Steven r. lindlandPENNSylvANiA, Brian D. HarePuErTO riCO, luis Santos, Jos E. Santana-PimentelrHODE iSlAND, robert Smith SOuTH CArOliNA, rob Bedenbaugh, Mark lester, Mitchell D. Metts SOuTH
15、DAKOTA, Michael Behm, Mark A. leifermanTENNESSEE, Michael Agnew, Jeff C. Jones, Carolyn Stonecipher TExAS, Mark A. Marek uTAH, Jesse Sweeten, lisa WilsonvErMONT, Kevin MarshiavirgiNiA, robert H. Cary, Mohammad Mirshahi, Barton A. ThrasherWASHiNgTON, Pasco Bakotich, Terry l. Berends, Nancy Boyd, Dave
16、 Olson WEST virgiNiA, gregory Bailey, Jason C. FosterWiSCONSiN, Jerry H. Zogg WyOMiNg, Tony lairdASSOCIATE MEMBERBridge, Port, and Toll NJ TurNPiKE AuTHOriTy, J. lawrence Williams POrT AuTHOriTy OF Ny AND NJ, Scott D. Murrell ASSOCIATE MEMBERFederal uSDA FOrEST SErviCE, Ellen g. laFayetteASSOCIATE M
17、EMBER International AlBErTA, Moh lali BriTiSH COluMBiA, richard voyer KOrEA, Chan-Su “Chris” reem ONTAriO, Joe Bucik SASKATCHEWAN, Sukhy Kent 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law. 2011 by the
18、American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.viiTable of ContentsPRefaCe xxviiChaPTeR 1an InTRoduCTIon To RoadsIde safeTy 1-11.0 HISTORY OF ROADSIDE SAFETY .1-11.1 THE BENEFITS OF ROADSIDE SAFETY 1-11.2 STRATEGIC
19、 PLAN FOR IMPROVING ROADSIDE SAFETY .1-21.3 GUIDE CONTENT AND FORMAT .1-41.4 CRASH TESTING ROADSIDE SAFETY FEATURES AND HARDWARE 1-41.5 THE APPLICATION OF THIS GUIDE .1-6ChaPTeR 2eConomIC evaluaTIon of RoadsIde safeTy 2-12.0 OVERVIEW 2-12.1 BENEFIT/COST ANALYSIS .2-12.1.1 Encroachments 2-22.1.2 Road
20、side Geometry.2-22.1.3 Crash Costs 2-22.2 BENEFIT/COST ANALYSIS PROGRAMS .2-22.3 IN-SERVICE PERFORMANCE EVALUATION 2-3ChaPTeR 3RoadsIde ToPogRaPhy and dRaInage feaTuRes .3-13.0 OVERVIEW 3-13.1 THE CLEAR-ZONE CONCEPT.3-13.2 ROADSIDE GEOMETRY .3-43.2.1 Foreslopes .3-43.2.2 Backslopes .3-63.2.3 Transve
21、rse Slopes .3-63.2.4 Drainage Channels 3-83.3 APPLICATION OF THE CLEAR-ZONE CONCEPT .3-103.3.1 Recoverable Foreslopes 3-113.3.2 Non-Recoverable Foreslopes 3-113.3.3 Critical Foreslopes .3-113.3.4 Examples of Clear-Zone Application on Variable Slopes .3-113.3.5 Clear-Zone Applications for Drainage Ch
22、annels and Backslopes .3-123.3.6 Clear Zone for Auxiliary Lanes and Freeway Ramps 3-123.4 DRAINAGE FEATURES .3-123.4.1 Curbs 3-133.4.2 Cross-Drainage Structures 3-13 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of appl
23、icable law.viii3.4.2.1 Traversable Designs .3-143.4.2.2 Extension of Structure .3-143.4.2.3 Shielding .3-163.4.3 Parallel Drainage Features .3-163.4.3.1 Eliminate the Structure 3-163.4.3.2 Traversable Designs .3-163.4.3.3 Relocate the Structure3-183.4.3.4 Shielding .3-193.4.4 Drop Inlets .3-193.5 Ex
24、AMPLES OF THE CLEAR-ZONE CONCEPT TO RECOVERABLE FORESLOPES 3-19ChaPTeR 4sIgn, sIgnal, and lumInaIRe suPPoRTs, uTIlITy Poles, TRees, and sImIlaR RoadsIde feaTuRes 4-14.0 OVERVIEW 4-14.1 ACCEPTANCE CRITERIA FOR BREAKAWAY SUPPORTS .4-24.2 DESIGN AND LOCATION CRITERIA FOR BREAKAWAY AND NON-BREAKAWAY SUP
25、PORTS 4-24.3 SIGN SUPPORTS 4-44.3.1 Overhead Sign Supports 4-44.3.2 Large Roadside Sign Supports .4-44.3.3 Small Roadside Sign Supports .4-74.4 MULTIPLE POST SUPPORTS FOR SIGNS .4-104.5 LUMINAIRE SUPPORTS .4-104.5.1 Breakaway Luminaire Supports 4-104.5.2 High-Level Lighting Supports .4-124.6 TRAFFIC
26、 SIGNAL SUPPORTS .4-124.7 SUPPORTS FOR MISCELLANEOUS DEVICES 4-134.7.1 Railroad Crossing Warning Devices .4-134.7.2 Fire Hydrants .4-134.7.3 Mailbox Supports 4-134.8 UTILITY POLES .4-134.9 TREES .4-15ChaPTeR 5RoadsIde BaRRIeRs .5-15.0 OVERVIEW .5-15.1 PERFORMANCE REQUIREMENTS 5-15.1.1 FHWA Acceptanc
27、e Letters .5-35.1.2 Standard Barrier Hardware Guide .5-35.2 BARRIER RECOMMENDATIONS 5-35.2.1 Roadside Geometry and Terrain Features 5-45.2.2 Roadside Obstacles 5-95.2.3 Bystanders, Pedestrians, and Bicyclists 5-10 2011 by the American Association of State Highway and Transportation Officials.All rig
28、hts reserved. Duplication is a violation of applicable law.ix5.2.4 Motorcycles and Barrier Design 5-105.3 TEST LEVEL SELECTION FACTORS .5-105.4 STRUCTURAL AND SAFETY CHARACTERISTICS OF ROADSIDE BARRIERS .5-115.4.1 Standard Sections of Roadside Barriers .5-115.4.1.1 Low-Tension Cable .5-135.4.1.2 Hig
29、h-Tension Cable .5-145.4.1.3 W-Beam (Weak Post) .5-145.4.1.4 Ironwood Aesthetic Guardrail .5-155.4.1.5 Box Beam (Weak Post) 5-155.4.1.6 Blocked-Out W-Beam (Strong Post) .5-165.4.1.7 Midwest Guardrail System (MGS) .5-185.4.1.8 Proprietary W-Beam Guardrail Systems5-205.4.1.8.1 Gregory Mini Spacer (GMS
30、) Guardrail System 5-215.4.1.8.2 Trinity T-31 Guardrail System 5-215.4.1.8.3 NU-GUARD 31 by Nucor Steel Marion, Inc. .5-225.4.1.9 Blocked-Out Thrie-Beam .5-235.4.1.9.1 Blocked-Out Thrie-Beam (Wood and Steel Strong Post) 5-235.4.1.9.2 Modified Thrie-Beam 5-235.4.1.9.3 Trinity T-39 Guardrail System .5
31、-245.4.1.10 Merritt Parkway Aesthetic Guardrail .5-255.4.1.11 Backed Timber Guardrail 5-265.4.1.12 Concrete Barriers .5-265.4.1.13 CUSHIONWALL II Crash Cushion System 5-295.4.1.14 Stone Masonry Wall/Precast Masonry Wall .5-295.4.2 Long-Span Guardrail Systems .5-305.4.3 Transition Designs 5-315.5 SEL
32、ECTION GUIDELINES 5-325.5.1 Barrier Performance Capability 5-325.5.2 Barrier Deflection Characteristics 5-335.5.3 Site Conditions .5-385.5.4 Compatibility .5-385.5.5 Life-Cycle Costs 5-385.5.6 Maintenance .5-385.5.6.1 Routine Maintenance 5-385.5.6.2 Crash Maintenance 5-385.5.6.3 Material and Storage
33、 Requirements .5-395.5.6.4 Simplicity of Barrier Design 5-395.5.7 Aesthetic and Environmental Considerations .5-395.5.8 Field Experience .5-39 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.x5.6 PLACEME
34、NT RECOMMENDATIONS 5-395.6.1 Barrier Offset 5-405.6.2 Terrain Effects .5-435.6.2.1 Curbs 5-435.6.2.1.1 Curb/Guardrail Combinations for Strong-Post W-Beam Guardrail 5-445.6.2.1.2 Crash Tested Curb/Guardrail Combinations .5-455.6.2.2 Slopes 5-465.6.3 Flare Rate 5-485.6.5 Grading for Terminals 5-595.6.
35、6 Guardrail Placed in a Radius 5-605.6.7 Guardrail Posts in Rigid Foundations .5-615.6.7.1 Guardrail Posts in Rock Formations.5-615.6.7.2 Guardrail Posts in Mow Strips .5-615.7 UPGRADING SYSTEMS 5-665.7.1 Structural Inadequacies .5-665.7.2 Design/Placement Inadequacies 5-665.7.3 Establishing Priorit
36、ies of Upgrading Needs .5-66ChaPTeR 6medIan BaRRIeRs .6-16.0 OVERVIEW .6-16.1 PERFORMANCE REQUIREMENTS 6-16.2 GUIDELINES FOR MEDIAN BARRIER APPLICATION .6-16.3 PERFORMANCE LEVEL SELECTION PROCEDURES .6-36.4 STRUCTURAL AND SAFETY CHARACTERISTICS OF MEDIAN BARRIERS .6-36.4.1 Crashworthy Median Barrier
37、 Systems .6-36.4.1.1 Weak-Post W-Beam Median Barrier .6-56.4.1.2 Low-Tension Cable Barrier 6-56.4.1.3 High-Tension Cable Barrier 6-66.4.1.4 Box-Beam Median Barrier .6-96.4.1.5 Blocked-Out W-Beam (Strong Post) .6-96.4.1.6 Blocked-Out Thrie-Beam (Strong Post) 6-106.4.1.7 Modified Thrie-Beam Median Bar
38、rier .6-106.4.1.8 Concrete Barrier 6-116.4.1.9 QuickchangeMoveable Barrier System .6-146.4.2 End Treatments .6-146.4.3 Transitions .6-166.5 SELECTION GUIDELINES 6-166.5.1 Barrier Performance Capability 6-166.5.2 Barrier Deflection Characteristics 6-166.5.3 Compatibility .6-16 2011 by the American As
39、sociation of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.xi6.5.4 Costs .6-176.5.5 Maintenance .6-176.5.6 Aesthetic and Environmental Considerations .6-176.5.7 Field Experience .6-176.6 PLACEMENT RECOMMENDATIONS 6-176.6.1 Terrain Effect
40、s .6-176.6.1.1 Median Section I .6-186.6.1.2 Median Section II 6-186.6.1.3 Median Section III .6-196.6.2 Fixed Objects within the Median .6-206.7 UPGRADING SYSTEMS 6-21ChaPTeR 7BRIdge RaIlIngs and TRansITIons .7-17.0 OVERVIEW 7-17.1 PERFORMANCE REQUIREMENTS .7-17.2 GUIDELINES .7-27.3 APPROPRIATE TES
41、T LEVEL SELECTION CONSIDERATIONS 7-27.4 CRASH-TESTED RAILINGS 7-27.4.1 NCHRP 350 TL-1 through TL-4 Bridge Railings 7-47.4.2 MASH TL-5 and TL-6 Bridge Railings .7-57.5 SELECTION GUIDELINES .7-67.5.1 Railing Performance 7-67.5.2 Compatibility 7-77.5.3 Costs 7-77.5.4 Field Experience 7-77.5.5 Aesthetic
42、s 7-77.5.6 Protective Screening at Overpasses .7-77.6 PLACEMENT RECOMMENDATIONS .7-87.6.1 Considerations for Urban and Low-Volume Roads 7-87.7 UPGRADING OF BRIDGE RAILINGS 7-107.7.1 Identification of Potentially Obsolete Systems 7-107.7.2 Upgrading Systems .7-117.7.2.1 Concrete Retrofit (Safety Shap
43、e or Vertical) .7-117.7.2.2 W-Beam or Thrie-Beam Retrofits .7-127.7.2.3 Metal Post-and-Beam Retrofits 7-137.8 TRANSITIONS .7-14ChaPTeR 8end TReaTmenTs 8-18.0 OVERVIEW 8-18.1 PERFORMANCE REQUIREMENTS .8-1 2011 by the American Association of State Highway and Transportation Officials.All rights reserv
44、ed. Duplication is a violation of applicable law.xii8.1.1 FHWA Acceptance Letters .8-28.1.2 Guide to Standardized Barrier Hardware .8-28.2 ANCHORAGE DESIGN CONCEPTS .8-28.3 TERMINAL DESIGN CONCEPTS 8-38.3.1 Compatibility of Terminals with Flexible and Semi-Rigid Barrier Systems 8-38.3.2 Performance
45、Characteristics of Terminals 8-48.3.2.1 Energy-Absorbing vs. Non-Energy-Absorbing Terminals 8-48.3.2.2 Flared versus Tangent Terminals .8-48.3.2.3 Length-of-Need Point .8-48.3.3 Site Grading Considerations for Terminals 8-48.3.3.1 Advance Grading 8-58.3.3.2 Adjacent Grading .8-58.3.3.3 Runout Distan
46、ce Grading .8-68.3.4 Terminals 8-78.3.5 Terminals for Cable Barrier Systems 8-78.3.5.1 Three-Strand Cable Terminal .8-78.3.5.2 Terminals for High-Tension Cable Barrier Systems .8-88.3.6 Terminals for W-Beam Guardrail Systems .8-98.3.6.1 Buried-in-Backslope Terminal 8-108.3.6.2 Flared W-Beam Terminal
47、s 8-118.3.6.2.1 Eccentric Loader Terminal (ELT) .8-118.3.6.2.2 Modified Eccentric Loader Terminal (MELT) 8-128.3.6.2.3 Flared Energy-Absorbing Terminal (FLEAT) 8-128.3.6.2.4 Slotted Rail Terminal (SRT-350) .8-128.3.6.2.5 x-Tension Guardrail End Terminal .8-138.3.6.3 Tangent W-Beam Terminals .8-148.3
48、.6.3.1 Extruder Terminal (ET-Plus) 8-148.3.6.3.2 Sequential Kinking Terminal (SKT-350) .8-158.3.6.3.3 x-Tension Guardrail Terminal .8-168.3.6.4 Terminals for 787-mm 31-in. Height Steel Beam Guardrail Systems 8-168.3.6.5 Median Terminals .8-168.3.6.5.1 Brakemaster 350 .8-168.3.6.5.2 Crash Cushion Att
49、enuating Terminal (CAT-350) 8-188.3.6.5.3 FLEAT Median Terminal (FLEAT-MT) .8-188.3.6.5.4 x-Tension Median Attenuator System (x-MAS) 8-188.3.7 Terminals for Box-Beam Guardrail 8-198.3.7.1 Wyoming Box-Beam End Terminal (WY-BET) 8-208.3.7.2 Bursting Energy Absorbing Terminal (BEAT) .8-208.4 CRASH CUSHION DESIGN CONCEPTS 8-21 2011 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.xiii8.4.1 Design Principles .8-228.4.1.1 Work-Energy Principle
