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2A-i July, 2012
Chapter 2A. GENERAL2A.1 Function and Purpose of Signs .............................................................................................2A-12A.2 Definitions ............................................................................................................................2A-12A.3 Standardization of Application .............................................................................................2A-12A.4 Excessive Use of Signs .........................................................................................................2A-12A.5 ClassificationofSigns ..........................................................................................................2A-22A.6 Design of Signs .....................................................................................................................2A-22A.7 RetroreflectivityandIllumination ........................................................................................2A-32A.8 MaintainingMinimumRetroreflectivity ..............................................................................2A-52A.9 Shapes ...................................................................................................................................2A-52A.10 Sign Colors ...........................................................................................................................2A-52A.11 Dimensions ...........................................................................................................................2A-72A.12 Symbols ................................................................................................................................2A-72A.13 Word Messages ......................................................................................................................2A-102A.14 Sign Borders .........................................................................................................................2A-112A.15 Enhanced Conspicuity for Standard Signs ...........................................................................2A-112A.16 Standardization of Location ..................................................................................................2A-132A.17 OverheadSignInstallations ..................................................................................................2A-172A.18 Mounting Height ...................................................................................................................2A-172A.19 LateralOffset ........................................................................................................................2A-182A.20 Orientation ............................................................................................................................2A-192A.21 Posts and Mountings .............................................................................................................2A-192A.22 Maintenance ..........................................................................................................................2A-192A.23 MedianOpeningTreatmentsforDividedHighwayswithWideMedians ...........................2A-19
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Chapter 2A. GENERALTABLE OF CONTENTS
FIGURESFigure2A-1 ExamplesofEnhancedConspicuityforSigns .......................................................................2A-12Figure2A-2 ExamplesofHeightsandLateralLocationsofSignInstallations .........................................2A-14Figure2A-3 ExamplesofLocationsforSomeTypicalSignsatIntersections ...........................................2A-15Figure2A-4 RelativeLocationsofRegulatory,Warning,andGuideSignsonanIntersectionApproach 2A-16
TABLESTable2A-1 IlluminationofSignElements ...............................................................................................2A-4Table2A-2 RetroreflectionofSignElements ...........................................................................................2A-4Table2A-3 MinimumMaintainedRetroreflectivityLevels......................................................................2A-6Table2A-4 UseofSignShapes ................................................................................................................2A-8Table2A-5 CommonUsesofSignColors ................................................................................................2A-9
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2A-1
2A.3 Standardization of Application Support
It is recognized thaturban trafficconditionsdiffer fromthoseinruralenvironments,andinmanyinstancessignsareappliedandlocateddifferently.Wherepertinentandpractical,thisManual sets forth separate recommendations forurbanand rural conditions. Guidance
Signsshouldbeusedonlywherejustifiedbyengineeringjudgmentorstudies,asprovidedinSection1A.9.
Results from trafficengineering studies of physical andtraffic factors should indicate the locationswhere signsaredeemednecessaryordesirable.
Roadwaygeometricdesignandsignapplicationshouldbecoordinatedsothatsigningcanbeeffectivelyplacedtogivethe roaduser anynecessary regulatory,warning, guidance,andotherinformation.
StandardEachstandardsignshallbedisplayedonlyforthespecific
purposeasprescribed in thisManual.Determinationof theparticular signs to be applied to a specific condition shallbemadeinaccordancewiththeprovisionssetforthinPart2. Before any new highway, private road open to publictravel(seedefinitioninSection1A.13),detour,ortemporaryrouteisopenedtopublictravel,allnecessarysignsshallbein place. Signs required by road conditions or restrictionsshallberemovedwhenthoseconditionsceasetoexistortherestrictionsarewithdrawn.
2A.4 Excessive Use of Signs Guidance
Regulatory and warning signs should be usedconservativelybecausethesesigns,ifusedtoexcess,tendtolose their effectiveness. Ifused, route signsanddirectionalguide signs should be used frequently because their usepromotesefficientoperationsbykeepingroadusersinformedof their location.
December,2011
2A.1 Function and Purpose of Signs Support
This Manual contains Standards, Guidance, and Options for the signingof all typesof highways, andprivate roadsopentopublictravel.Thefunctionsofsignsaretoprovideregulations, warnings, and guidance information for roadusers.Words, symbols, and arrows are used to convey themessages.Signsarenottypicallyusedtoconfirmrulesoftheroad.DetailedsignrequirementsarelocatedinthefollowingChapters of Part 2:
Chapter 2B – Regulatory Signs, Barricades, and Gates Chapter2C–WarningSignsandObjectMarkersChapter 2D – Guide Signs for Conventional Roads Chapter2E–GuideSignsforFreewaysandExpresswaysChapter 2F – Toll Road Signs Chapter 2G – Preferential and Managed Lane Signs Chapter2H–GeneralInformationSignsChapter2I–GeneralServiceSignsChapter2J–SpecificService(Logo)SignsChapter 2K – Tourist-Oriented Direction Signs Chapter2L–ChangeableMessageSignsChapter2M–RecreationalandCulturalInterestArea
Signs Chapter2N–EmergencyManagementSigns
StandardBecausetherequirementsandstandardsforsignsdepend
ontheparticulartypeofhighwayuponwhichtheyaretobeused, thedefinitions for freeway, expressway, conventionalroads, and special purpose road given in Section 1A.13 shall apply in Part 2.
2A.2 DefinitionsSupport
Definitions that are applicable to signs are given inSections 1A.13 and 1A.14.
PART 2. SIGNSChapter 2A. GENERAL
2A-2December, 2011
Uniformityindesignshallincludeshape,color,dimensions,legends,borders,andilluminationorretroreflectivity.
Standardization of these designs does not preclude furtherimprovementbyminorchangesintheproportionororientationofsymbols,widthofborders,orlayoutofwordmessages,butallshapesandcolorsshallbeasindicated.
All symbols shall be unmistakably similar to ormirrorimagesoftheadoptedsymbolsigns,allofwhichareshowninthe MnDOT Standard Signs and Markings Manual and the Federal “StandardHighwaySigns”book (seeSection1A.11). Symbols and colors shall not be modified unlessotherwisestatedherein.Allsymbolsandcolorsforsignsnotshown in the“StandardHighwaySigns”bookshall followtheproceduresforexperimentationandchangedescribedinSection 1A.10.
OptionAlthoughthestandarddesignofsymbolsignscannotbe
modified, theorientationof thesymbolmaybechanged tobetterreflectthedirectionoftravel,ifappropriate.
StandardWhereastandardwordmessageisapplicable,thewording
shallbeashereinprovidedinthisManual.Insituationswherewordmessagesarerequiredotherthan
thoseprovidedinthisManual,thesignsshallbeofthesameshapeandcolorasstandardsignsofthesamefunctionaltype.
Option State and local highway agenciesmaydevelop special
wordmessagesignsinsituationswhereroadwayconditionsmake it necessary to provide road users with additionalregulatory,warning,orguidanceinformation,suchaswhenroadusersneedtobenotifiedofspecialregulationsorwarnedaboutasituationthatmightnotbereadilyapparent.Unlikecolorsthathavenotbeenassignedorsymbolsthathavenotbeen approved for signs, newwordmessage signsmaybeusedwithouttheneedforexperimentation.
StandardExcept as provided in the option below and except for
the Carpool Information (D12-2) sign (see Section 2I.11),Internet addresses and e-mail addresses, including domainnames and uniform resource locators (URL), shall not bedisplayed on any sign, supplemental plaque, sign panel(including logo sign panels on Specific Service signs) orchangeablemessagesigns.
2A.5 ClassificationofSignsStandard
Signsshallbedefinedbytheirfunctionasfollows:A. Regulatory signs give notice of traffic laws or
regulations. B. Warningsignsgivenoticeofasituationthatmight
notbereadilyapparent.C. Guidesignsshowroutedesignations,destinations,
directions, distances, services, points of interest, and other geographical, recreational, or cultural information.
SupportObjectmarkersaredefinedinSection2C.63.
2A.6 Design of Signs Support
ThisManualshowsmanytypicalstandardsignsandobjectmarkers approved for use on streets, highways, bikeways,and pedestrian crossings.
In the specifications for individual signs and objectmarkers,thegeneralappearanceofthelegend,color,andsizeareshownintheaccompanyingtablesandillustrations,andarenotalwaysdetailedinthetext.
Detailed drawings of standard signs, object markers,alphabets,symbolsandarrows(seeFigure2D-2)areshownin the MnDOT “Standard Signs and Markings Manual”and the Federal “Standard Highway Signs andMarkings”book.Section1A.11containsinformationregardinghowtoobtainthesepublications.
Thebasicrequirementsofasignarethatitbelegibletothoseforwhomitisintendedandthatitbeunderstandableintimetopermitaproperresponse.Desirableattributesinclude:
A. Highvisibilitybydayandnight;andB. Highlegibility(adequatelysizedletters,symbols,or
arrows,andashortlegendforquickcomprehensionbyaroaduserapproachingasign).
Standardizedcolorsandshapesarespecifiedso that theseveralclassesof trafficsignscanbepromptly recognized.Simplicityanduniformityindesign,position,andapplicationareimportant.
StandardThe term legend shall include all word messages and
symboldesignsthatareintendedtoconveyspecificmeanings.
2A-3 December, 2011
OptionSignelementsmaybeilluminatedbythemeansshownin
Table2A-1.Retroreflection of sign elements may be by the means
showninTable2A-2.Light Emitting Diode (LED) units may be used
individually within the legend or symbol of a sign and intheborderofasign,exceptforChangeableMessageSigns,to improve the conspicuity, increase the legibility of signlegendsandborders,orprovideachangeablemessage.
StandardExcept as provided in the Option below, neither
individualLEDsnorgroupsofLEDsshallbeplacedwithinthebackgroundareaofasign.
Ifused,theLEDsshallhaveamaximumdiameterof1/4inchandshallbethefollowingcolorsbasedonthetypeofsign:
A. Whiteorred,ifusedwithSTOPorYIELDsigns.B. White, if used with regulatory signs other than
STOPorYIELDsigns.C. Whiteoryellow,ifusedwithwarningsigns.D. White,ifusedwithguidesigns.E. White, yellow, or orange, if usedwith temporary
trafficcontrolsigns.F. Whiteoryellow,ifusedwithschoolareasigns.
Ifflashed, allLEDunits shallflash simultaneously at arateofmorethan50andlessthan60timesperminute.
The uniformity of the sign design shall be maintainedwithout any decrease in visibility, legibility, or drivercomprehensionduringeitherdaytimeornighttimeconditions.
OptionForSTOPandYIELDsigns,LEDsmaybeplacedwithin
theborderorwithinoneborderwidthwithinthebackgroundof the sign.
For STOP/SLOW paddles (see Section 6E.03) used byflaggersandtheSTOPpaddles(seeSection7D.05)usedbyadult crossing guards, individual LEDs or groups of LEDs maybeused.
SupportOthermethodsofenhancingtheconspicuityofstandard
signsaredescribedinSection2A.15.Informationregarding theuseof retroreflectivematerial
on the sign support is contained in Section 2A.21.
GuidanceUnlessotherwiseprovided in thisManual foraspecific
sign, and except as provided in the Option below, phonenumbersofmorethanfourcharactersshouldnotbeusedonany sign, supplemental plaque, sign panel (including logopanelsonlogosigns)orchangeablemessagesign.
OptionInternetaddressese-mailaddresses,ortelephonenumbers
withmore than fourcharactersmaybedisplayedonsigns,supplemental plaque, signpanels, and changeablemessagesigns that are intended for viewing only by pedestrians,bicyclists, occupants of parked vehicles, or drivers ofvehiclesonlow-speedroadwayswhereengineeringjudgmentindicatesthatanareaisavailablefordriverstostopoutofthetrafficflowtoreadthemessage.
StandardPictographs (see definition in Section 1A.13) shall
not be displayed on signs except as specifically providedin this Manual. Pictographs shall be simple, dignified,and devoid of any advertising. When used to represent a political jurisdiction (such as aState, county, ormunicipalcorporation) thepictographshallbe theofficialdesignationadoptedbythejurisdiction.Whenusedtorepresentacollegeoruniversity,thepictographshallbetheofficialsealadoptedby the institution. Pictorial representations of university orcollegeprogramsshallnotbepermitted tobedisplayedona sign.
2A.7 RetroreflectivityandIlluminationSupport
There are many materials currently available forretroreflection and variousmethods currently available fortheilluminationofsignsandobjectmarkers.Newmaterialsandmethodscontinuetoemerge.Newmaterialsandmethodscanbeusedaslongasthesignsandobjectmarkersmeetthestandardrequirementsforcolor,bothbydayandbynight.
StandardRegulatory,warning,andguidesignsandobjectmarkers
shall be retroreflective (see Section 2A.08) or illuminatedtoshow thesameshapeandsimilarcolorbybothdayandnight,unlessotherwiseprovidedinthetextdiscussioninthisManual for a particular sign or group of signs.
The requirements for sign illumination shall not beconsidered to be satisfied by street, highway, or strobelighting.
2A-4July, 2013
MeansofIllumination SignElementtoBeIlluminated
Light behind the sign face. • Symbolorwordmessage• Background• Symbol,wordmessage,andbackground(through
atranslucentmaterial)
Attachedorindependentlymountedlightsourcedesignedtodirectessentiallyuniformilluminationonto the sign face.
• Entire sign face
Lightemittingdiodes(LEDs) • Symbolorwordmessage• Portions of the sign border
Otherdevices,ortreatmentsthathighlightthesignshape,color,ormessage:
LuminoustubingFiber opticsIncandescent light bulbsLuminescentpanels
• Symbolorwordmessage• Entire sign face
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Table 2A-1 Illumination of Sign Elements
MeansofRetroreflection SignElement
Reflector“buttons”orsimilarunits • Symbol• Wordmessage• Border
Amaterialthathasasmooth,sealedoutersurfaceoveramicrostructurethatreflectslight
• Symbol• Wordmessage• Border• Background
Table 2A-2 Retroreflection of Sign Elements
2A-5 July, 2012
D. BlanketReplacement–Allsignsinanarea/corridor,orofagiventype,shouldbereplacedatspecifiedintervals. This eliminates the need to assessretroreflectivityortrackthelifeofindividualsigns.Thereplacementintervalisbasedontheexpectedsignlife,comparedtotheminimumlevels,fortheshortestlifematerialusedontheaffectedsigns.
E. ControlSigns–Replacementofsigns in thefieldisbasedontheperformanceofasampleofcontrolsigns.The control signsmight be a small samplelocated in a maintenance yard or a sample ofsignsinthefield.Thecontrolsignsaremonitoredtodetermine theendof retroreflective life for theassociated signs. All field signs represented bythe control sample should be replaced before theretroreflectivity levelsof thecontrolsamplereachtheminimumlevels.
F. OtherMethods–Othermethodsdevelopedbasedonengineeringstudiescanbeused.
SupportAdditionalinformationaboutthesemethodsiscontained
in the 2007 Edition of FHWA’s “Maintaining Traffic SignRetroreflectivity”(seeSection1A.11).
OptionHighwayagenciesmayexcludethefollowingsignsfrom
theretroreflectivitymaintenanceguidelinesdescribedinthisSection:
A. Parking,Standing,andStoppingsigns(R7andR8series)
B. Walking/Hitchhiking/Crossing signs (R9 series,R10-1throughR10-4b)
C. Acknowledgmentsigns,includingMemorialsignsD. AllsignswithblueorbrownbackgroundsE. Bikewaysigns thatare intendedforexclusiveuse
bybicyclistsorpedestrians2A.9 Shapes Standard
Particular shapes, as shown in Table 2A-4, shall beusedexclusivelyforspecificsignsorseriesofsigns,unlessotherwiseprovidedinthetextdiscussioninthisManualforaparticular sign or class of signs.
2A.10 Sign Colors Thecolorstobeusedonstandardsignsandtheirspecific
use on these signs shall be as provided in the applicableSections of this Manual. The color coordinates and values shall be as described in 23 CFR, Part 655, Subpart F,Appendix..
2A.8 MaintainingMinimumRetroreflectivity
SupportRetroreflectivityisoneofseveralfactorsassociatedwith
maintainingnighttimesignvisibility(seeSection2A.22).
StandardPublicagenciesorofficialshavingjurisdictionshalluse
an assessment ormanagementmethod that is designed tomaintain sign retroreflectivity at or above the minimumlevelsinTable2A-3.
ComplianceDate:June13,2014
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SupportCompliance with the above Standard is achieved by
havingamethodinplaceandusingthemethodtomaintainthe minimum levels established in Table 2A-3. Providedthatanassessmentormanagementmethodisbeingused,anagencyorofficialhavingjurisdictionwouldbeincompliancewith the above Standard even if there are some individualsignsthatdonotmeettheminimumretroreflectivitylevelsataparticularpointintime.Guidance
Except for those signs specifically identified in thefollowingOption,oneormoreofthefollowingassessmentor management methods should be used to maintain signretroreflectivity:
A. VisualNighttimeInspection–Theretroreflectivityof an existing sign is assessed by a trained signinspector conducting a visual inspection from amovingvehicleduringnighttimeconditions.Signsthatarevisuallyidentifiedbytheinspectortohaveretroreflectivitybelowtheminimumlevelsshouldbereplaced.
B. Measured Sign Retroreflectivity – Signretroreflectivity is measured using aretroreflectometer. Signs with retroreflectivitybelowtheminimumlevelsshouldbereplaced.
C. Expected Sign Life – When signs are installed, the installationdateislabeledorrecordedsothattheageofasignisknown.Theageofthesigniscomparedto the expected sign life. The expected sign life is based on the experience of sign retroreflectivitydegradation inageographicareacompared to theminimumlevels.Signsolderthantheexpectedlifeshouldbereplaced.
2A-6December, 2011
Sign Color
SheetingType(ASTMD4956-04)
AdditionalCriteria
Beaded Sheeting PrismaticSheeting
I II III III,IV,VI,VII,VIII,IX,X
White on GreenW*; G≥7 W*; G≥15 W*; G≥25 W≥250; G≥25 Overhead
W*; G≥7 W≥120; G≥15 Post-Mounted
Black on Yellow Y*; O* Y≥50; O≥50 ②
Black on Orange Y*; O* Y≥75; O≥75 ③
White on Red W≥35; R≥7 ④
Black on White W≥50 --
① The minimum maintained retroreflectivity levels shown in this table are in units of cd/lx/m2 measured at an observation angle of 0.2o and an entrance angle of -4.0o.② For text and fine symbol signs measuring at least 48 inches and for all sizes of bold symbol signs.③ For text and fine symbol signs measuring less than 48 inches.④ Minimum Sign Contrast ratio > 3:1 (white retroreflectivity - red retroreflectivity).
* This sheeting type shall not be used for this color for this application except as noted in 2A.8.
BoldSymbolSigns
• W1-1, -2 -- Turn and Curve• W1-3, -4 -- Reverse Turn and Curve• W1-5 -- Winding Road• W1-6, -7 -- Large Arrow• W1-8 -- Chevron• W1-10 -- Intersection in Curve• W1-11 -- Hairpin Curve• W1-15 -- 270 Degree Loop• W2-1 -- Cross Road• W2-2, -3 -- Side Road• W2-4, -5 -- T and Y Intersection• W2-6 -- Circular Intersection• W2-7, -8 -- Double Side Roads
• W3-1 -- Stop ahead• W3-2 -- Yield Ahead• W3-3 -- Signal Ahead• W4-1 -- Merge• W4-2 -- Lane Ends• W4-3 -- Added Lane• W4-5 -- Entering Roadway Merge• W4-6 -- Entering Roadway Added Lane• W6-1, -2 -- Divided Highway Begins and Ends• W6-3 -- Two-Way Traffic• W10-1, -2, -3 -4, -11, -12 -- Grade Crossing Advance Warning
• W11-2 -- Pedestrian Crossing• W11-3, -4, 16 thru 22 -- Large Animals• W11-5 -- Farm Equipment• W11-6 -- Snowmobile Crossing• W11-7 -- Equestrian Crossing• W11-8 -- Fire Station• W11-10 -- Truck Crossing• W12-1 -- Double Arrow• W16-5p, -6p, -7p -- Pointing Arrow
Plaques• W20-7 -- Flagger• W21-1 -- Worker
FineSymbolSigns-SymbolsignsnotlistedasBoldSymbolSigns.
Special Cases
• W3-1 -- Stop Ahead: Red retroreflectivity ≥ 7• W3-2 -- Yield Ahead: Red retroreflectivity ≥ 7; White retroreflectivity ≥ 35• W3-3 -- Signal Ahead: Red retroreflectivity ≥ 7; Green retroreflectivity ≥ 7• W3-5 -- Speed Reduction: White retroreflectivity ≥ 50• For non-diamond shaped signs such as W14-3 (No Passing Zone), W4-4p (Cross Traffic Does Not Stop), or W13-1P, -2, -3, -6, -7 (Speed Advisory Plaques,
use the largest sign dimension to determine proper minimum retroreflectivity level.
Table 2A-3 Minimum Maintained Retroreflectivity Levels
2A-7 December, 2011
SupportAs a quick reference, common uses of sign colors are
shown inTable 2A-5.Color schemes on specific signs areshownintheillustrationslocatedineachappropriateChapter.
WheneverwhiteisspecifiedinthisManual,the MnDOT “Standard Signs and Markings Manual”, or in the Federal “StandardHighwaySignsand Markings” book (see Section 1A.11)asacolor, it isunderstoodtoincludesilver-coloredretroreflectivecoatingsorelementsthatreflectwhitelight.
ThecolorscoralandlightbluearebeingreservedforusesthatwillbedeterminedinthefuturebytheFederalHighwayAdministration.
Information regarding color coding of destinations onguide signs, including community wayfinding signs, iscontained in Chapter 2D.
OptionThe approved fluorescent version of the standard red,
yellow,green,ororangecolormaybeusedasanalternativeto the corresponding standard color.
2A.11 DimensionsSupport
The MnDOT “Standard Signs and Markings Manual” and the Federal“StandardHighwaySignsandMarkings”book(seeSection1A.11)prescribedesigndetailsforuptofivedifferentsizesdependingon the typeof trafficfacility,includingbikeways.Smallersizesaredesignedtobeusedonbikewaysandsomeotheroff-roadapplications.Largersizesaredesignedforuseonfreewaysandexpressways,andcanalso be used to enhance road user safety and convenienceonotherfacilities,especiallyonmulti-lanedividedhighwaysandonundividedhighwayshavingfiveormorelanesoftrafficand/orhighspeeds.Theintermediatesizesaredesignedtobeusedonotherhighwaytypes.
StandardThestandardsigndimensionsprescribedinAppendix C of
this Manual and in the Federal“StandardHighwaySigns”book (seeSection 1A.11) shall be used unless engineeringjudgmentdeterminesthatothersizesareappropriate.Exceptasprovidedintheoptionbelow,whereengineeringjudgmentdeterminesthatsizessmallerthantheprescribeddimensionsareappropriateforuse,thesigndimensionsshallnotbelessthan theminimumdimensionsspecified inAppendix C of this Manual.ThesizesshownintheMinimumcolumnsthataresmaller than thesizesshownin theConventionalRoadcolumnsinthevarioussignsize
tables in this Manual shall only be used on low-speedroadways, alleys, and private roads open to public travelwhere the reduced legend size would be adequate for theregulationorwarningorwherephysicalconditionsprecludethe use of larger sizes.
OptionForalleyswithrestrictivephysicalconditionsandvehicle
usagethatlimitsinstallationoftheminimumsizesign(ortheConventionalRoadsizesignifnoMinimumsizeisshown),boththesignheightandthesignwidthmaybedecreasedbyup to 6 inches.Guidance The sizes shown in the Freeway andExpressway columnsinthevarioussignsizetablesinthisManualshouldbeusedon freeways and expressways, and for other higher-speedapplications based upon engineering judgment, to providelargersignsforincreasedvisibilityandrecognition.
ThesizesshownintheOversizedcolumnsinthevarioussignsizetablesinthisManualsizeshouldbeusedforthosespecial applications where speed, volume, or other factorsresult in conditions where increased emphasis, improvedrecognition,orincreasedlegibilityisneeded,asdeterminedbyengineeringjudgmentorstudy.
Increasesabovetheprescribedsizesshouldbeusedwheregreaterlegibilityoremphasisisneeded.Ifsignslargerthanthe prescribed sizes are used, the overall sign dimensionsshouldbeincreasedin6-inchincrements.
StandardWhere engineering judgment determines that sizes that
aredifferentthantheprescribeddimensionsareappropriateforuse,standardshapesandcolorsshallbeusedandstandardproportionsshallberetainedasmuchaspractical.Guidance
Whensupplementalplaquesareinstalledwithlargersizedsigns, a corresponding increase in the size of the plaque and its legend should also be made. The resulting plaque sizeshouldbeapproximately in the same relativeproportion tothe larger sized sign as the conventional sized plaque is to the conventional sized sign.
2A.12 SymbolsStandard
Symboldesignsshallinallcasesbeunmistakablysimilarto those shown in this Manual, the MnDOT “Standard Signs and Markings Manual”, and the Federal “Standard HighwaySignsandMarkings”book(seeSection1A.11).
2A-8December, 2011
Shape Signs
Octagon Stop *
Equilateral Triangle (1 point down) Yield *
Circle Grade Crossing Advance Warning *
Pennant Shape / Isosceles Triangle (longer axis horizontal)
No Passing *
Pentagon (pointed up) School Advance Warning Sign (squared bottom corners) *County Route Sign (tapered bottom corners) *
Crossbuck(two rectangles in an “X” configuration)
Grade Crossing *
Diamond Warning Series
Rectangle (including square) Regulatory SeriesGuide Series **Warning Series
Trapezoid Recreational and Cultural Interest Area SeriesNational Forest Route Sign
*Thissignshallbeexclusivelytheshapeshown.**Guideseriesincludesgeneralservice,specificservice,tourist-orienteddirectional,generalinformation,recreationalandculturalinterestarea,andemergencymanagementsigns.
Table 2A-4 Use of Sign Shapes
2A-9 December, 2011
Type of Sign
Legend Background
Blac
k
Gre
en
Red
Whi
te
Yello
w
Ora
nge
Fluo
resc
ent
Yello
w-G
reen
Fluo
resc
ent
Pink
Blac
k
Blue
Brow
n
Gre
en
Ora
nge*
Red
*
Whi
te
Yello
w*
Purp
le
Fluo
resc
ent
Yello
w-G
reen
Fluo
resc
ent
Pink
Regulatory X X X X X X
Prohibitive X X X X
Permissive X X
Warning X X
Pedestrian X X X
Bicycle X X X
Guide X X
Interstate Route X X X X
State Route X X
US Route X X
County Route X X X X X
Forest Route X X
Street Name X X
Destination X X
Reference Location X X
Information X X X
Evacuation Route X X
Road User Service X X
Recreational X X X
Temporary Traffic Control X XIncident Management X X XSchool X X
ETC Account Only X ****X
Changeable Message Signs
Regulatory ***X X
Warning X Temporary Traffic Control X X
Guide X **X
Motorist Services X **X
Incident Management X X School, Pedestrian Bicycle X X
*Fluorescentversionsofthesebackgroundcolorsmayalsobeused.**ThesealternativebackgroundcolorswouldbeprovidedbyblueorgreenlightedpixelssuchthattheentireCMSwouldbelighted,notjustthelegend.
***Redisusedonlyforthecircleandslashorotherredelementsofasimilarstaticregulatorysign.****TheuseofthecolorpurpleonsignsisrestrictedpertheprovisionsofSection2F.3,Standard,firstparagraph.
Table 2A-5 Common Uses of Sign Colors
2A-10December, 2011
SupportSection 2M.07 contains provisions for the use of
recreational and cultural interest area symbols to indicateprohibitedactivitiesoritemsinnon-roadapplications.
2A.13 Word MessagesStandard
Except asprovided inSection2A.6, allwordmessagesshall use standard wording and letters as shown in thisManual, the MnDOT “Standard Signs and Markings Manual”, and the Federal “StandardHighwaySignsandMarkings”book(seeSection1A.11).Guidance
Word messages should be as brief as possible and thelettering should be large enough to provide the necessarylegibilitydistance.Aminimumratioof1inchofletterheightper30feetoflegibilitydistanceshouldbeused.
Abbreviations (see Section 1A.15) should be kept to aminimum.
Wordmessagesshouldnotcontainperiods,apostrophes,questionmarks, or other punctuationor characters that arenot letters,numerals,orhyphensunlessnecessary toavoidconfusion.
Thesolidus(slantedlineorforwardslash)isintendedtobeusedforfractionsonlyandshouldnotbeusedtoseparatewordsonthesamelineoflegend.Instead,ahyphenshouldbeusedforthispurpose,suchas“TRUCKS-BUSES.”
StandardFractions shall be displayed with the numerator and
denominatordiagonallyarrangedabout thesolidus(slantedlineor forwardslash).Theoverallheightof the fraction ismeasuredfromthetopofthenumeratortothebottomofthedenominator, each of which is vertically aligned with theupper and lower endsof the solidus.Theoverall heightofthefractionshallbedeterminedbytheheightofthenumeralswithin the fraction,andshallbe1.5 times theheightofanindividualnumeralwithinthefraction.
SupportThe MnDOT “Standard Signs and Markings Manual”
and the Federal “Standard Highway Signs and Markings” book (see Section 1A.11) contain details regarding the layouts of fractions on signs.
Newsymboldesignsshall be submitted to theFederalHighway Administration for adoption based on researchevaluations to determine road user comprehension, signconspicuity,andsignlegibility.
SupportSometimes a change from word messages to symbols
requiressignificanttimeforpubliceducationandtransition.Therefore, thisManual sometimes includes the practice ofusingeducationalplaquestoaccompanynewsymbolsigns.Guidance
New warning or regulatory symbol signs not readilyrecognizable by the public should be accompanied by aneducational plaque.
OptionEducationalplaquesmaybeleftinplaceaslongasthey
areinserviceablecondition.State and/or local highway agencies may conduct
researchstudiestodetermineroadusercomprehension,signconspicuity,andsignlegibility.Guidance
Although most standard symbols are oriented facingleft,mirror imagesof thesesymbols shouldbeusedwherethe reverseorientationmightbetter convey to roadusers adirectionofmovement.
StandardAsymbolusedforagivencategoryofsigns(regulatory,
warning,orguide)shallnotbeusedforadifferentcategoryofsigns,exceptasspecificallyauthorizedinthisManual.
Exceptasprovidedinthefollowingoption,arecreationalandculturalinterestareasymbol(seeChapter2M)shallnotbe used on streets or highways outside of recreational andcultural interest areas.
Arecreationalandculturalinterestareaguidesignsymbol(see Chapter 2M) shall not be used on any regulatory orwarningsignonanystreet,road,orhighway.
OptionA recreational and cultural interest area guide sign
symbol(seeSection2M.04)maybeusedonahighwayguidesign outside of a recreational and cultural interest area to supplementacomparablewordmessage forwhich there isnoapprovedsymbolforthatmessageinChapters2Bthrough2Ior2N.
2A-11 December, 2011
SupportSection 2D.4 contains information regarding the
acceptablemethodsofmodifyingthelengthofawordforagiven letter height and series.
2A.14 Sign Borders Standard
Unless otherwise provided, each sign illustrated in thisManualshallhaveaborderofthesamecolorasthelegend,atorjustinsidetheedge.
Thecornersofthesignshallberounded,exceptforSTOPsigns. Guidance
Adarkborderonalightbackgroundshouldbesetinfromtheedge,whilealightborderonadarkbackgroundshouldextend to the edge of the sign.A border for 30-inch signswith a light background shouldbe from1/2 to 3/4 inch inwidth,1/2inchfromtheedge.Forsimilarsignswithalightborder,awidthof1inchshouldbeused.Forothersizes,theborderwidthshouldbeofsimilarproportions,butshouldnotexceedthestroke-widthofthemajorletteringofthesign.Onsignsexceeding72x120 inches insize, thebordershouldbe2incheswide,oronlargersigns,3incheswide.ExceptforSTOPsignsandasotherwiseprovidedinSection2E.16,thecornersofthesignshouldberoundedtoaradiusthatisconcentricwiththatoftheborder.
2A.15 EnhancedConspicuityforStandardSigns
OptionBaseduponengineeringjudgment,wheretheimprovement
oftheconspicuityofastandardregulatory,warning,orguidesignisdesired,anyofthefollowingmethodsmaybeused,as appropriate, to enhance the sign’s conspicuity (see Figure 2A-1):
A. Increasing the size of a standard regulatory,warning,orguidesign.
B. Doubling-upofastandardregulatory,warning,orguidesignbyaddingasecondidenticalsignontheleft-handsideoftheroadway.
C. Adding a solid yellow or fluorescent yellowrectangular “header panel” above a standardregulatory sign, with the width of the panelcorresponding to the width of the standardregulatory sign.A legendof“NOTICE,”“STATELAW,”orotherappropriate textmaybeadded inblackletterswithintheheaderpanelforaperiodoftimedeterminedbyengineeringjudgment.
GuidanceWhen initials are used to represent an abbreviation for
separatewords(suchas“US”foraUnitedStatesroute),theinitialsshouldbeseparatedbyaspaceofbetween1/2and3/4of the letter height of the initials.
WhenanInterstaterouteisdisplayedintextforminsteadofusingtherouteshield,ahyphenshouldbeusedforclarity,suchas“I-50.”
StandardAllsignletteringshallbeinupper-caselettersasprovided
intheMnDOT“StandardSignsandMarkingsManual”andtheFederal“StandardHighwaySignsandMarkings”book(see Section 1A.11)), unless otherwise provided in thisManualforaparticularsignortypeofmessage.
The sign lettering for names of places, streets, andhighwaysshallbecomposedofacombinationoflower-caseletterswithinitialupper-caseletters.
SupportLetter height is expressed in terms of the height of an
upper-caseletter.Formixed-caselegends(thosecomposedofaninitialupper-caseletterfollowedbylower-caseletters),theheightofthelower-caselettersisderivedfromthespecifiedheightof the initialupper-case letterbasedonaprescribedratio. Letter heights for mixed-case legends might beexpressedintermsofboththeupper-andlowercaseletters,orintermsoftheinitialupper-caseletteralone.Whentheheightof a lower-case letter is specified or determined from theprescribedratio,thereferenceistothenominalloopheightoftheletter.Thetermloopheightreferstotheportionofalower-caseletterthatexcludesanyascendingordescendingstemsortailsoftheletter,suchaswiththeletters“d”or“q.”The nominal loop height is equal to the actual height of anon-roundedlower-caseletterwhoseformdoesnotincludeascendingordescendingstemsortails,suchastheletter“x.”The roundedportionsofa lower-case letterextendslightlyabove and below the baselines projected from the top andbottomofsuchanonroundedlettersothattheappearanceofauniformletterheightwithinawordisachieved.Theactualloopheightofaroundedlower-caseletterisslightlygreaterthan the nominal loop height and this additional height isexcludedfromtheexpressionofthelower-caseletterheight.
StandardWhen a mixed-case legend is used, the height of the
lower-case letters shall be 3/4 of the height of the initialupper-case letter.
TheuniqueletterformsforeachoftheStandardAlphabetseries shall not be stretched, compressed, warped, orotherwisemanipulated.
2A-12December, 2011
J. Addinglightemittingdiode(LED)unitswithinthesymbolorlegendofasignorborderofastandardregulatory,warning,orguide sign,asprovided inSection 2A.07.
K. Adding a strip of retroreflective material to thesignsupport incompliancewith theprovisionsofSection 2A.21.
L. Usingothermethods that are specifically allowedfor certain signs as described elsewhere in thisManual.
SupportSign conspicuity improvements can also be achieved
byremovingnon-essentialand illegalsigns fromtheright-ofway(seeSection1A.8),andbyrelocatingsignstoprovidebetterspacing.
StandardTheNEWplaque(seeSection2C.62)shallnotbeused
alone. Strobelightsshallnotbeusedtoenhancetheconspicuity
ofhighwaysigns.
Figure 2A-1 Examples of Enhanced Conspicuity for Signs
D. AddingaNEWplaque(seeSection2C.62)abovea new standard regulatory orwarning sign, for aperiodoftimedeterminedbyengineeringjudgment,tocallattentiontothenewsign.
E. Addingoneormore redororangeflags (clothorretroreflectivesheeting)aboveastandardregulatoryorwarningsign,withtheflagsorientedsoastobeat 45 degrees to the vertical.
F. Addingasolidyellow,asolidfluorescentyellow,oradiagonallystripedblackandyellow(orblackandfluorescentyellow)stripofretroreflectivesheetingat least 3 inches wide around the perimeter of astandardwarningsign.Thismaybeaccomplishedby affixing the standard warning sign on abackgroundthatis6incheslargerthanthesizeofthestandardwarningsign.
G. Addingawarningbeacon(seeSection4L.03)toastandard regulatory (other than a STOP or a Speed Limitsign),warning,orguidesign.
H. Adding a speed limit sign beacon (see Section4L.04)toastandardSpeedLimitsign.
I. Adding a stop beacon (see Section 4L.05) to aSTOP sign.
2A-13 December, 2011
SupportTheclearzoneisthetotalroadsideborderarea,starting
at theedgeof the traveledway,available forusebyerrantvehicles. The width of the clear zone is dependent upontraffic volumes, speeds, and roadside geometry.Additionalinformationcanbefoundinthe“AASHTORoadsideDesignGuide”(seeSection1A.11).Guidance
With the increase in traffic volumes and the desireto provide road users regulatory, warning, and guidanceinformation,anorderofpriorityforsigninstallationshouldbeestablished.
SupportAnorderofpriorityisespeciallycriticalwherespaceis
limitedforsigninstallationandthereisademandforseveraldifferent types of signs. Overloading road users with toomuchinformationisnotdesirable.Guidance
Because regulatory and warning information is morecriticaltotheroaduserthanguidanceinformation,regulatoryand warning signing whose location is critical should bedisplayedratherthanguidesigningincaseswhereconflictsoccur. Community wayfinding and acknowledgment guidesignsshouldhavealowerpriorityastoplacementthanotherguide signs. Informationof a less criticalnature shouldbemovedtolesscriticallocationsoromitted.
OptionUndersomecircumstances,suchasoncurvestotheright,
signsmaybeplacedonmedian islandsoron the left-handsideoftheroad.Asupplementarysignlocatedonthelefthandsideoftheroadwaymaybeusedonamulti-laneroadwheretraffic in a lane to the rightmightobstruct theview to theright.
At wide-throat intersections with corner radii over 40 feet, a STOP sign may be placed up to 50 feet from the major roadway. Consider increasing the size of the STOP sign and adding a stop bar closer to the major roadway.
When the corner radii exceeds 90 feet, consider redesigning the intersection in order to provide a free right turn lane and a raised island (see Figure 2A.2) with the STOP sign installed on the island.
2A.16 Standardization of Location Support
Standardizationofpositioncannotalwaysbeattainedinpractice.Examplesofheightsand lateral locationsofsignsfor typical installations are illustrated in Figure 2A-2, and examplesoflocationsforsometypicalsignsatintersectionsare illustrated in Figures 2A-3 and 2A-4.
Examplesofadvancesigningonanintersectionapproachare illustrated in Figure 2A-4. Chapters 2B, 2C, and 2D contain provisions regarding the application of regulatory, warning,andguidesigns,respectively.
StandardSignsrequiringseparatedecisionsbytheroadusershall
bespacedsufficientlyfarapartfortheappropriatedecisionstobemade.Oneofthefactorsconsideredwhendeterminingtheappropriatespacingshallbethepostedor85th-percentilespeed.Guidance
Signs should be located on the right-hand side of theroadwaywheretheyareeasilyrecognizedandunderstoodbyroadusers.Signsinotherlocationsshouldbeconsideredonlyassupplementarytosignsinthenormallocations,exceptasotherwiseprovidedinthisManual.
Signsshouldbeindividuallyinstalledonseparatepostsormountingsexceptwhere:
A. Onesignsupplementsanother;B. Route or directional signs are grouped to clarify
informationtomotorists;C. Regulatory signs that do not conflict with each
other are grouped, such as turn prohibition signspostedwithonewaysignsoraparkingregulationsignpostedwithaspeedlimitsign;or
D. Street name signs are postedwith a stopor yieldsign.
Signsshouldbelocatedsothatthey:A. Are outside the clear zone unless placed on a
breakawayoryieldingsupport(seeSection2A.19),B. Optimizenighttimevisibility,C. Minimizetheeffectsofmudsplatteranddebris,D. Donotobscureeachother,E. Donot obscure the sight distance to approaching
vehicles on the major street for drivers who arestoppedonminor-streetapproaches,and
F. Arenothiddenfromview.
2A-14December, 2011
Note:See Section 2A.19 for reduced lateral offset distances that may be used in areas where lateral offsets are limited, and inbusiness, commercial, or residential areas where sidewalk width is limited or where existing poles are close to the curb.
5 ft.Minimum
A - ROADSIDE SIGN IN RURAL AREA
C - ROADSIDE SIGN IN BUSINESS, COMMERCIAL, OR RESIDENTIAL AREA
12 ft.Minimum
7 ft.*Minimum
* Where parking or pedestrian movements are likely to occur
D - WARNING SIGN WITH SPEED PLAQUE IN RURAL AREA
F - SIGN ON NOSE OF MEDIAN
B - ROADSIDE SIGN IN RURAL AREA
E - ROADSIDE ASSEMBLY IN RURAL AREA
Shoulder wider than 6 ft.
12 ft.Minimum
12 ft.Minimum
6 ft.Minimum
2 5
50SP EEDL I M I T
2 ft.Minimum
7 ft.Minimum
4 ft.Minimum
5 ft.Minimum
4 ft.Minimum
1 4 6 8
5 ft.Minimum
H - OVERHEAD MOUNTING
SHOULDER
6 ft.Minimum
17 ft.Minimum
E M a i n S t
G - FREEWAY OR EXPRESSWAY SIGN WITH SECONDARY SIGN
SHOULDER
12 ft.Minimum
6 ft.Minimum
5 ft.Minimum
8 ft.Minimum
N E XT E X I T7 M I L E S
M e i re G rove M e l ro s e
12/ M I L EE X I T
Figure 2A-2 Examples of Heights and Lateral Locations of Sign Installations
2A-15 December, 2011
A - ACUTE ANGLE INTERSECTION
C - MINOR CROSSROAD
E - DIVISIONAL ISLAND F - WIDE THROAT INTERSECTION
D - URBAN INTERSECTION
B - CHANNELIZED INTERSECTION
See Note
See Note
See Note
See Note
See Note
2 ft Minimum
2 ft. Minimum
50 ft. Maximum
SIDEWALK
MINORROAD
MAJORROAD
Y I E LD
MARKED ORUNMARKEDCROSSWALK
2 ft. Minimum
4 ft. Minimum
Note: Lateral offset is a minimum of 6 feet measured from the edge of the shoulder, or 12 feet measured from the edge of the traveled way. See Section 2A.19 for lower minimums that may be used in urban areas, or where lateral offset space is limited.
Figure 2A-3 Examples of Locations for Some Typical Signs at Intersections
2A-16December, 2011
foot major road offset should be maintained because a larger offset would require drivers on the minor road to either stop twice or look for a longer gap. When corner radii exceeds 90 feet, it is not possible to comply with both the minor and major road offsets. Redesigning the intersection in order to provide a free right turn island would provide a protected location for the STOP sign consistent with the optimum major and minor road offsets.
SupportSTOP signs are typically located within 6 to 12 feet of
the edge of the traveled portion of intersecting roadways (see Figure 2A-2) in order to place vehicles stopped on the minor road in a location that optimizes sight lines to the major roadway. At wide throat intersections with large corner radii (over 40 feet), this optimum sign location would result in the STOP sign being placed in the paved part of the road. In these cases, the 50
STATE ROUTE4
Benson Road
Weiss Ave
A - Single-lane approach B - Multi-lane approach
4
D o ra nW h e a t o n
4 30
EAST
Notes: See Chapter 2D for information on guide signs and Part 3 for information on pavement markings
See Table 2C-4 for the recommended minimum distanceSee Section 2C.46 for the application of the W2-1 signand Section 2C.36 for the application of the W3-1 signsSee Section 2B.22 for the application of IntersectionLane Control signs
G o d a h lS t J a m e s
B e n so n Rd We i ss Ave
200 ft. Minimum
200 ft.Minimum
*
200 ft.Minimum
200 ft.Minimum
200 ft.Minimum
*
200 ft.Minimum
400 ft. Minimum
600 ft. Minimum
800 ft. Minimum
W2-1 W3-1
(Optional)
** **
*****
*
***O N LYO N LY
Figure 2A-4 Relative Locations of Regulatory, Warning, and Guide Signs on an Intersection Approach
2A-17 December, 2011
2A.18 Mounting Height Standard
The provisions of this Section shall apply unless specificallystatedotherwiseforaparticularsignelsewherein this Manual.
SupportThemountingheightrequirementsforobjectmarkersare
provided in Chapter 2C. InadditiontotheprovisionsofthisSection,information
affectingtheminimummountingheightofsignsasafunctionofcrashperformancecanbefoundinAASHTO’s“RoadsideDesignGuide”(seeSection1A.11).
StandardThe minimum height, measured vertically from the
bottomof the sign to theelevationof thenearedgeof thepavement,ofsigns installedat thesideof theroad inruralareasshallbe5feet(seeFigure2A-2).
The minimum height, measured vertically from thebottomofthesigntothetopofthecurb,or intheabsenceofcurb,measuredverticallyfromthebottomofthesigntotheelevationof thenearedgeof thetraveledway,ofsignsinstalledatthesideoftheroadinbusiness,commercial,orresidentialareaswhereparkingorpedestrianmovementsarelikelytooccurdirectly below the sign,orwheretheviewofthesignmightbeobstructed,shallbe7feet(see Figure 2A- 2).
The minimum height, measured vertically from thebottomofthesigntothesidewalk,ofsignsinstalledabovesidewalksshallbe7feet.Ifthebottomofasecondarysignthatismountedbelowanothersignismountedlowerthan7feetaboveapedestriansidewalkorpathway(seeSection6D.02),thesecondarysignshallnotprojectmorethan4inchesintothe pedestrian facility (see Figure 2A-2, Example C).
Directional signs on freeways and expressways shallbe installed with a minimum height of 7 feet, measuredverticallyfromthebottomofthesigntotheelevationofthenear edgeof thepavement.All route signs,warning signs,and regulatory signs on freeways and expressways shallbe installed with a minimum height of 7 feet, measuredverticallyfromthebottomofthesigntotheelevationofthenearedgeof thepavement. Ifasecondarysign ismountedbelowanother signona freewayor expressway, themajorsignshallbeinstalledwithaminimumheightof8feetandthesecondarysignshallbeinstalledwithaminimumheightof5feet,measuredverticallyfromthebottomofthesigntotheelevationofthenearedgeofthepavement.
GuidanceInurbanareaswherecrosswalksexist, signsshouldnot
be placed within 4 feet in advance of the crosswalk (seeDrawingDinFigure2A-3).
2A.17 Overhead Sign Installations Guidance
Overhead signs should be used on freeways andexpressways, where some degree of lane-use control isdesirable,orwherespaceisnotavailableattheroadside.
SupportThe operational requirements of the present highway
system are such that overhead signs have value at manylocations.Thefactorstobeconsideredfortheinstallationofoverheadsigndisplaysarenotdefinableinspecificnumericalterms.
OptionThefollowingconditions (not inpriorityorder)maybe
consideredinanengineeringstudytodetermineifoverheadsignswouldbebeneficial:
A. Trafficvolumeatornearcapacity;B. Complexinterchangedesign;C. Threeormorelanesineachdirection;D. Restrictedsightdistance;E. Closelyspacedinterchanges;F. Multi-laneexits;G. Largepercentageoftrucks;H. Streetlightingbackground;I. High-speedtraffic;J. Consistency of sign message location through a
seriesofinterchanges;K. Insufficientspaceforpost-mountedsigns;L. Junctionoftwofreeways;andM. Leftexitramps.
Over-crossingstructuresmaybeusedtosupportoverheadsigns.
SupportUnder some circumstances, the use of over-crossing
structuresassignsupportsmightbetheonlypracticalsolutionthatwillprovideadequateviewingdistance.Theuseofsuchstructuresassignsupportsmighteliminatetheneedforthefoundations and sign supports along the roadside.
2A-18July, 2013
Post-mounted sign and object marker supports shall be crashworthy (breakaway, yielding, or shielded with alongitudinalbarrierorcrashcushion)ifwithintheclearzone.
ComplianceDate:January17,2013The compliance date applies only to those roads with
posted or statutory speed limits 50 mph and greater. All other roads with speed limits less than 50 mph are to comply through attrition.Guidance
For post-mounted signs, the minimum lateral offsetshouldbe12feetfromtheedgeofthetravelway.Ifapavedshoulderwiderthan6feetexists,theminimumlateraloffsetforpost-mountedsignsshouldbe6feetfromtheedgeoftheshoulder.
SupportThe minimum lateral offset requirements for object
markersareprovidedinChapter2C.Theminimumlateraloffsetisintendedtokeeptrucksand
carsthatusetheshouldersfromstrikingthesignsorsupports.Guidance
All supports shouldbe locatedas far aspractical fromtheedgeoftheshoulder.Advantageshouldbetakentoplacesigns behind existing roadside barriers, on over-crossingstructures,orother locationsthatminimizetheexposureofthetraffictosignsupports.
SupportWhere permitted, signs may be placed on existing
supports used for other purposes, such as highway trafficsignalsupports,highwaylightingsupports,andutilitypoles.
StandardIfsignsareplacedonexistingsupports, theyshallmeet
otherplacementcriteriacontainedinthisManual.
OptionLesserlateraloffsetsmaybeusedonconnectingroadways
or rampsat interchanges,butnot less than6 feet from theedgeofthetraveledway.
OnconventionalroadsinareaswhereitisimpracticaltolocateasignwiththelateraloffsetprescribedbythisSection,alateraloffsetofatleast2feetmaybeused.
Alateraloffsetofatleast1footfromthefaceofthecurbmay be used in business, commercial or residential areaswheresidewalkwidthislimitedorwhereexistingpolesareclosetothecurb.
Mn
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. 2
Where large signs having an area exceeding 50 square feet areinstalledonmultiplebreakawayposts,theclearancefromthegroundtothebottomofthesignshallbeatleast7feet.
OptionTheheight to thebottomofa secondarysignmounted
below another sign may be 1 foot less than the heightspecifiedabove.
Signsthatareplaced30feetormorefromtheedgeofthetraveledwaymaybeinstalledwithaminimumheightof5feet,measuredverticallyfromthebottomofthesigntotheelevationofthenearedgeofthepavement.
A route sign assembly consisting of a route sign andauxiliarysigns(seeSection2D.12)maybetreatedasasinglesign for the purposes of this Section.
Themountingheightmaybeadjustedwhensupportsarelocatedneartheedgeoftheright-of-wayonasteepbackslopeinordertoavoidthesometimeslessdesirablealternativeofplacingthesignclosertotheroadway.
StandardOverheadmountedsignsshallprovideaverticalclearance
ofnotlessthan17feettothesign,lightfixture,orsignbridge,overtheentirewidthofthepavementandshouldersexceptwhere a lesser vertical clearance is used for the design ofother structures.
OptionIf the vertical clearance of other structures along the
roadway near the sign structure is less than 16 feet, thevertical clearance to an overhead sign structure or support maybeaslowas1foothigherthantheverticalclearanceoftheotherstructuresinordertoimprovethevisibilityoftheoverhead signs.
Inspecialcasesitmaybenecessarytoreducetheclearanceto overhead signs because of substandard dimensions intunnels and other major structures such as double-deckbridges.
SupportFigure 2A-2 illustrates some of the mounting height
requirementscontainedinthisSection.
2A.19 LateralOffsetStandard
For overhead sign supports, theminimum lateral offsetfromtheedgeoftheshoulder(orifnoshoulderexists,fromtheedgeofthepavement)tothenearedgeofoverheadsignsupports(cantileverorsignbridges)shallbe6feet.Overheadsignsupportsshallhaveabarrierorcrashcushiontoshieldthemiftheyarewithintheclearzone.
Mn
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. 1
2A-19 July, 2013
StandardIf a strip of retroreflectivematerial is used on the sign
support,itshallbeatleast2inchesinwidth,itshallbeplacedforthefulllengthofthesupportfromthesigntowithin2feetabovetheedgeoftheroadway,anditscolorshallmatchthebackgroundcolorofthesign,exceptthatthecolorofthestripfortheYIELDandDONOTENTERsignsshallbered.
2A.22 Maintenance Guidance
Maintenance activities should consider proper position, cleanliness, legibility, and daytime and nighttime visibility(seeSection2A.8).Damagedordeterioratedsigns,gates,orobjectmarkersshouldbereplaced.
Toassureadequatemaintenance,ascheduleforinspecting(bothdayandnight),cleaning,andreplacingsigns,gates,andobjectmarkersshouldbeestablished.Employeesofhighway,law enforcement, and other public agencies whose dutiesrequirethattheytravelontheroadwaysshouldbeencouragedtoreportanydamaged,deteriorated,orobscuredsigns,gates,orobjectmarkersatthefirstopportunity.
Stepsshouldbetakentoseethatweeds,trees,shrubbery,and construction, maintenance, and utility materials andequipment do not obscure the face of any sign or objectmarker.
A regular schedule of replacement of lighting elementsforilluminatedsignsshouldbemaintained.
2A.23 MedianOpeningTreatmentsforDividedHighwayswithWideMedians
GuidanceWhere two roadwaysareseparatedbya median and
themedianwidthattheintersectionis30feetormore,theintersectionshouldbesignedastwoseparateintersections.[Minnesota Statute 169.011, Subd. 36, (b)] (see Figures 2B- 12 and 2B-15).
Mn
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. 2
GuidanceOverheadsignsupportsandpost-mountedsignandobject
markersupportsshouldnotintrudeintotheusablewidthofasidewalkorotherpedestrianfacility.
SupportFigures2A-2and2A-3 illustrate someexamplesof the
lateraloffsetrequirementscontainedinthisSection.
2A.20 Orientation Guidance
Unlessotherwiseprovided in thisManual, signs shouldbevertically-mountedatrightanglestothedirectionof,andfacing,thetrafficthattheyareintendedtoserve.
Wheremirrorreflectionfromthesignfaceisencounteredto suchadegreeas to reduce legibility, the sign shouldbeturnedslightlyawayfromtheroad.Signsthatareplaced30feetormorefromthepavementedgeshouldbeturnedtowardthe road. On curved alignments, the angle of placementshouldbedeterminedbythedirectionofapproachingtrafficratherthanbytheroadwayedgeatthepointwherethesignis located.
OptionOngrades,signfacesmaybetiltedforwardorbackfrom
theverticalpositiontoimprovetheviewingangle.
2A.21 Posts and Mountings Standard
Sign posts, foundations, and mountings shall be soconstructed as to hold signs in a proper and permanentposition,andtoresistswayinginthewindordisplacementbyvandalism.
SupportThe latest edition of AASHTO’s “Specifications for
Structural Supports for Highway Signs, Luminaires, andTraffic Signals” contains additional information regardingpostsandmounting(seePageiforAASHTO’saddress).
OptionWhere engineering judgment indicates a need to draw
attention to the sign during nighttime conditions, a stripof retroreflective material may be used on regulatory andwarningsignsupports.
