Introduction: Principles and Guidelines

This section describes the principles ofsigning. Included is information on:message preparation and sign legendcontent, mounting methods and place-ment guidelines, material selection, andmaintenance procedures. It is importantthat these guidelines be followed whenplanning, specifying, and placing signs atCorps projects.

Each sign in this manual has beendesigned for a specific purpose and isavailable from approved sources.

All Standard Identification and directionalsigns are made to order. They followspecified grids, material specifications,and fabrication techniques. All signsshown in this manual are part of a totalCorps sign system.

Each type of sign used on a Corps projector facility has been specified in thismanual either by function (identification,direction, information, safety, etc.), or bylocation (campground, boat ramp, lock,dam, building interior, etc.).

All signs in this manual have beendesigned around their intended function.For example, signs requiring an immedi-ate response from the viewer aresuccinctly worded. Signs viewed frommoving vehicles are sized larger thansigns read by pedestrians. Safety andtraffic signs adopt standard colors formaximum recognition. Informational signsplaced at recreation areas are designedto be visually harmonious with theenvironment.

EP 310-1-6a01 Jun 06

2-1

Because of the variety of environmentalconditions affecting sign placement, andbecause of the different legends on signsfor specific locations, effective signprogram implementation requires a clearunderstanding of the following principlesand guidelines.

Design and installation of directional signson public roads must be fully coordinatedwith the local or state highway department.

Questions not answered in this manualshould be referred to the district SignProgram Manager.

Standards set forth by this manual,including , but not limited to, thoserelated to color, type face/fonts, formats,proportions, and Danger, Warning andCaution legends, are mandatory. Only theHQ Sign Program Proponent may grantauthority for deviation. The balance ofthis manual constitutes guidance basedon signage principles. This guidanceshould be followed to the greatestdegree possible.

Sign Message

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EP 310-1-6a01 Jun 06

A sign is designed for the first-timeviewer, so sign legends must be briefand easy to understand. Use as fewwords as possible to communicate thedesired message.

All signs, with the exception ofdirectionals, should convey no morethan one concept or thought. Twothoughts require two separate signs.For this reason, the Corps Communica-tion Mark (logo) should not be placedon signs other than those used specifi-cally for identification, approach roadwaydirection, or as indicated in this manual.

Incorrect - Use of Corps Mark onProject Roadway Directional sign isnot acceptable

Sign messages should be concise, pre-ferably no more than ten words. If alonger legend is necessary, break it upinto a short headline, in larger letters,over the rest of the text. This increasesthe sign’s “glance” legibility (see page2-3).

Correct - No unnecessary informationon Project Roadway Directional sign

Incorrect - Message long and wordy

Correct - Headline gives priority to mostimportant information

To decide what words should be placedon a sign, here are some guidelines tofollow:

1) Legend: Evaluate what information isneeded at that specific point. a) Only provide the information neces-sary to make a decision at that particularlocation. b) On directional signs, do not anticipatedecisions that can be made later; unneces-sary information will confuse the viewer. c) Provide a second sign at the nextdecision point. As the user moves througha project, the information on signs shouldprogress from general to specific.

Most general

More specific Most specific

2) Sign Type: Define the type of sign thatis required at that location to communicatethe necessary information. Each signshould have a single purpose. Forexample, a site identification sign shouldonly identify a site as outlined in Section 5.It should not have other kinds of informa-tion on it such as: directional instructions(Section 6), regulatory restrictions (Section8), or fee symbol (Section 7). A dual-purpose sign dilutes the impact of bothmessages.

Incorrect - Inappropriate information on anidentification sign

Correct - Three signs, each with theappropriate information

3) Language: Use proper and consistentnomenclature. The words used to conveyinformation should be familiar and comfort-able to the viewer. The same wordingshould be used throughout a project.

Incorrect - Technical language notobvious to the public

Correct - Simplified language

5) Positive Tone: Whenever possible,messages should be presented usingpositive wording, unless it dilutes theclarity of the thought being communicated.

6) Information Order: Determine thehierarchy of information. Western culturesread line-to-line from top to bottom, left toright. In general, the most importantmessage should appear on the first line.

Correct - Two signs with the same message inEnglish and Spanish

4) Non-English Signs: In areas where asignificant percentage of the populationspeaks primarily in a foreign language, theuse of symbol signs (see Section 8) isstrongly encouraged. When no symbolsexist or where words are essential, twosigns - one in English and one in theforeign language - should be placed sideby side. These signs will follow the sameformat: same overall size, letter size andstyle, color, and mounting. Because ofvariations in dialect, the legends on non-English signs shall be developed at thelocal level. Two languages should neverappear on the same sign.

Naturally, sign messages for motoristsmust be briefer than those viewed bypedestrians.

Sign Panel Design EP 310-1-6a01 Jun 06

2-3

Grid format

An effectively designed sign integrates aclear, succinct legend with legible, well-spaced typography. The typographyshould be sized, spaced, and positionedso that the type does not appear to bleedoff the edge.

Following are elements that are to beconsidered in the design of a sign:

1) Legibility: Typography and panel sizemust be appropriate for the distance andspeed at which a sign is viewed. Thequalities of an effective sign should alsoinclude the following: pure legibility,glance legibility, target value, and priorityvalue. a) Pure legibility is the maximumdistance at which sign copy can be readunder optimum conditions, i.e., with nodistraction and unlimited time. b) Glance legibility is the distance atwhich a sign can be read swiftly andaccurately, such as when a driver mustremain aware of other cars and has onlya fleeting glimpse of the sign. c) Target value is the characteristic bywhich a sign stands out as different frombackground objects. d) Priority value is the characteristic bywhich one sign is seen first from among anumber of other similar or identical signs.

2) Sign Format: The philosophy of thismanual is that all signs within a project

a) Sign Background: The space on thesign panel around the sign legend isimportant for the readibility of the sign.The border creates a field that separatesthe sign legend from distracting environ-mental conditions behind the sign. Thisincreases the target value of the sign andcreates a neutral field for the placement ofthe legend. If the legend is placed too

close to the edge of the sign panel, it mayappear to bleed off the edge of the panelwhen viewed from the targeted distance.

Incorrect - Panel too small for type

To maximize the target value of a sign, itmust have sufficient background area andcontrast so that a driver can distinguish itin complex driving environments. Theremust also be sufficient contrast betweenthe letters and the sign background sothat a driver can read the message easily.It is generally recognized that maximizingthe background area around the legendwill dramatically increase the legibility ofthe message.

Correct - Proper size panel for type

should follow a similar format. Thiscontinuity of design will provide a finishedlook to the area and will assist the visitorto identify quickly the message that isconveyed. The majority of signs used atCorps projects have been standardized.However, some signs may be required forspecific purposes not covered in thismanual. All special signs should use thegrid format for signs of the same functionaltype as shown in this manual.

Sign Panel Design (cont’d)EP 310-1-6a01 Jun 06

2-4

Incorrect - Sign without borders

b) Border: The function of the border isthat of a “visual container” of the mes-sage. It is most effective at night whenthe border on the top and bottom of thepanel is caught and illuminated byheadlights, which heightens the targetvalue and signals to the driver thelocation of the sign. On dark backgroundsigns, the border will generally be thesame color as the lettering. Contrastingthe border with the background heightensthe target value of the sign when thecolor value in the surrounding environ-ment is similar to the value of the signpanel.

Correct - Sign with borders

c) Flush Left Legends: The legends ofmost signs shown in this manual use aflush left/rag right format. This meansthat the legend is aligned flush to the leftof the layout grid margin. The look of theunjustified right margin is determined byline-break and legend placement withinthe format.

This type of layout has greater readibilitythan if the legend is centered or justified.By using this format throughout, visualconsistency is added to all types of signsused in the Corps sign system.

Incorrect - Centered type

Incorrect - Justified type

Correct - Flush left type on grid format

d) Legend Line Length: When prepar-ing signs with site-specific legends,visualize the selected message on thesign panel. The look of the sign will bedetermined in part by the number ofwords and their layout on the sign panel.How many words, their length, and thelength of each line of copy are all factorsaffecting the look of the sign. Theappropriate layout of a sign legendshould be carefully designed for: visualbalance, legibility, and communicativeimpact.

It should be noted that words with thesame number of letters may havedifferent lengths. The actual length willdepend on the letters in each word. Forexample, the words “campground” and“recreation” each have ten letters. Yet

when set in type, “campground” is longerbecause it has individual letters that arewider.

A single message on a sign may be placedon two or more lines to maintain theproportions of the sign panel, except wherelimited by established grids.

Incorrect - Single line creates awkward panel

Incorrect - Line-break good, but panelunnecessarily long

Correct - Proper line-break for visualbalance and pleasing panel shape

A two-line message is visually stronger ifthe first line is slightly longer than thesecond.

A three-line message generally hasgreater visual balance if the middle line isslightly longer than the other two.Obviously, some sign legends will notline-break with this visual consistency.However, it is most important thatextreme differences in line length shouldbe minimized, if possible.

Line length can be reduced by utilizingcommonly recognized abbreviations,such as St. for Saint or Mt. for Mount.Proper names, however, should alwaysbe written out in full and placed on oneline. Additional examples of proper line-break formats are shown on pages 5-9to 5-11.

The actual length of a legend can becalculated using the method outlined onpage D.2.

Typography EP 310-1-6a01 Jun 06

2-5

The Corps sign system uses the HaasHelvetica letter style for all sign legends.This sans serif typeface is both highlylegible and readily available to manufac-turers. Used in the system are threedifferent weights (stroke widths), each fora specific purpose.

The primary weight, Helvetica Bold, isused for all Standard Identification signsand primary legends on most other typesof signs specified in this manual.

Helvetica Medium is used for waterwaysigns, recreation signs meant to beviewed from the water, and directionalsigns.

Helvetica Regular is used for all buildinginterior signs and for selected supportlegends in combination with the HelveticaBold typeface.

Complete displays of these letter-stylesare shown in Appendix D.

The following examples describe thecorrect use of typography on Corpssigns.

1) Upper and Lower Case Legends: Foroptimum readability, the legends of mostsigns specified in this manual have upperand lower case legends with initial capitalletters. Studies have shown that lowercase legends (initial capitals only) areread and understood considerably fasterthan all upper case sign legends. Upperand lower case words create forms andpatterns making each word unique. Thisincreases perceptibility and legibility.

Incorrect - All capital letters

Correct - Initial capital letters

Tests show that legends set in all uppercase letters must be read letter for letter,with the exception of only the mostcommon words like LEFT, RIGHT, CAU-TION, or STOP, which are read as a formbecause of a lifetime of conditioning.

2) Letter- and Word-Spacing Typographyviewed from a distance, such as on signs,must have more open letter spacing thantypography viewed at close proximity. Thespacing between letters in words andbetween words must be correct foroptimum readibility. To ensure correctletter- and word-spacing for all Corpssigns, a spacing guide is provided inAppendix D.

3) Line-Space: The space betweenmultiple-line sign legends is called line-space. The line-space of the examplesshown in this manual have been calcu-lated for good legibility and readibility.Multiple-line messages are intended to beread as a group without the lines bleedingtogether when viewed from a distance.Line-space between two different mes-sages is greater than line-space betweenlines of the same multiple-line messagegroup.

Incorrect - Equal line-spacing between alllegend lines

Correct - Line-spacing varies according to thesense of the legend

4) Legend Sizes and Viewing DistanceGuidelines: The appropriate size letter isselected for a sign so that the legend willbe readable from the viewing distancedesired. To that end, most of the signsshown in the manual are available in morethan one size so that the properly sizedsign can be viewed for the specificlocation.

Once the appropriate viewing distance hasbeen calculated, use the chart on page2-6 to determine the appropriate size ofthe primary legend typography of the sign.All signs in the system will be sizedaround the capital letter height (A) of theprimary legend of the sign.

When measuring the size of a capitalletter-form, only use flat letters(ABDEFHIKLMNPRTVWXYZ). Roundletters (CGJOQSU) will not give anaccurate measurement because they aredrawn to extend slightly above and belowthe base line and height line, respectively.This enlargement compensates for the factthat round shapes appear smaller thansquare shapes placed in the same sizeborder.

Incorrect - Same size round letter looks smallerthan flat letter

Correct - Round letter looks the same assmaller flat letter

Spacing too tight for signs

Correct spacing for signs

Spacing too open for signs

Viewing Distance GuideEP 310-1-6a01 Jun 06

The viewing distance charts below are aguide to sign letter size. Sizes are basedon the distance at which a proposed signis to be viewed. Type sizes are calcu-lated to meet the U.S. Department ofTransportation-Federal Highway Admin-istration (FHWA) Standards for visualacuity.

To determine the legend size for signswhere reaction time is not a critical factor,use Table A. The capital letter height

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Table A: This table identifies the correct signlegend size as calculated from the proposedviewing distance, for signs read on projectroads at slow approach speeds, as viewed bypedestrians, or from slow moving water craft.This chart is applicable for most all signs shownin the manual except where reaction time is afactor.

Legend size calculations for vehicles are shownfor low MPH viewing. Adjustments for higherspeed reaction times, or viewing from a widercone of vision are not included in Table A.Letter sizes for these conditions must becalculated on a site-by-site basis, using FHWAstandards or refer to the viewing distance/reaction time calculations.

For waterway signs, refer to the sign legendsizes shown to the right. For distances greaterthan 1,512 feet, the capital letter height (A) ofthe sign legend is calculated by dividing theviewing distance by 28 and rounding up to thenearest inch. For example, a sign viewed from2,000 feet would require a legend height of 72”(2,000 ÷ 28 = 71.428, and round up to 72”).Sign placement guidelines for waterways areprovided in Section 14.

sizes provided in the second columncorrespond to the standard type sizesspecified throughout this manual.

To keep Standard Identification signsfrom becoming overly large relative totheir placement location, use Table A.

Table B is used for signs read fromapproaching automobiles, and incorpo-rates reaction time and advanced signplacement location into the formula. This

is used primarily for directional signs.

All legends use upper and lower casetype. The type size is calculated from theheight of the initial capital letter. This sizeis referred to as “A” throughout thismanual.

Remember that these charts provideguidelines, not mandatory specifications.However, necessary deviations from thecharts shall be documented in the signplan.

Table B: This table identifies letter size as afunction of viewing distance and reaction time.It describes the location in which the sign is tobe placed in advance of the destination whenviewed from an approaching vehicle.

This table is only to be used for comparativepurposes and general reference. A detailedguideline for determining legend size, signplacement, and required reaction time isprovided on pages 2-17 to 2-19.

All letter sizes are calculated for people with aminimum visual acuity of 20/40, in compliancewith FHWA standards.

*Operating speed is the 85th percentile speed.

Note: All dimensions have been rounded up tothe nearest standard size. All desired signplacement distances (higher number) havebeen rounded up to the nearest 100 feet.

Legend: 200/600 = minimum distance/desireddistance.

0-20 3 200/600 400/90090 4

Operating Detection & Single Lane Multi-LaneViewing LetterSpeed* Recognition Approach ApproachDistance Size

Time

In Advance of LocationSign Placement Distance

(MPH) (Seconds) (Feet) (Feet)(Feet) (Inches)

21-25 3 200/600 500/900110 4

26-30 3 250 600/ 600/900135 6

31-35 3 300 600/ 725/900155 6

36-40 3 375 1300/ 875 1300/180 9

41-45 3 475/1300 1000/1300200 9

46-50 3 500/1300 1100/1300220 9

51-55 3 575/2600 1250/2600250 12

56-60 3 650/2600 1400/2600275 12

61-65 3 725 2600/ 1550-2600300 12

0-20 .75

Viewing distance Capital letter height Application:(In feet): (In inches):

21-27 1

28-41 1.5

42-55 2

56-83 3

84-111 4

112-167 6

168-251 9

252-335 12

336-503 18

504-671 24

672-839 30

840-1007 36

1008-1175 42

1176-1343 48

1344-1512 54

Sign Placement Distancein Advance of Location

Sign Color EP 310-1-6a01 Jun 06

Viewer response time is a function oftarget value and legibility. In turn, thesefactors are dependent on contrastbetween the legend and backgroundcolor of the sign and on the contrastbetween the sign and the environment.The primary factors in obtaining a hightarget value are size of the panel usedand color of the sign background. Ofcolor combinations, black and whitecombinations offer the greatest colorcontrast but are the least desirablebecause of poor contrast with theenvironment, which is predominantlyblack, white, and gray. Appropriatecolors have been specified for eachdifferent type of sign shown in thismanual. Three functional criteria areused in the selection of the appropriatecolor for sign legend and panel combina-tions. These include: color association,contrast, and target value.

1) Color Association: Many sign typesinherit their color standards from othersign color systems. These include theManual on Uniform Traffic ControlDevices for traffic signs, and the Occupa-tional Safety and Health AdministrationStandards for safety-related signs.Generally these adopted color systemsare quite appropriate for their intendedpurposes. Viewers are familiar with thecoded messages of these color combina-tions - red and white: danger; yellow andblack: caution; etc.

2-7

The communicative value of signs withsimilar functions is heightened by theirassociation with these recognizedfunctional color combinations.

2) Contrast: The difference in color value(light and dark) between message andbackground must be great enough forgood legibility. Legibility is increasedwhen a light color is used on a darkbackground. The reverse combinationtends to “wash out” the legend becauseof the diffusion of light from the lighterbackground.

3) Target Value: This characteristiccauses a sign to stand out from othersigns and objects in the environment.The target value of a sign is increased bysize, color contrast to the environment,and sign layout. The signs shown in thismanual have been sized and designedfor good target value for their functionsand intended placement locations.

Dark on light

Light on dark

Tone on tone

The color of a sign contributes to itstarget value

Sign PlacementEP 310-1-6a01 Jun 06

The following are general guidelines forplacing signs viewed from an approach-ing vehicle as well as for mounting signsfor pedestrian viewing. Guidelines forspecific sign types are shown in theirrespective sections, and general trafficsign placement guidelines are shown onpage 9-8.

1) Straight Ahead: Sign placement mustbe within the approaching driver’simmediate cone-of-vision. Drivers cannotbe expected to turn their heads to read asign. Signs mounted more than 40 feetoff the roadway because of specialcircumstances may require use of alarger panel to increase readabilitybecause the sign is outside the normalcone-of-vision.

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A driver’s cone of vision

2) Perpendicular: The sign face should beperpendicular to the approaching viewer.Never place a sign parallel to passingtraffic.

Signs placed perpendicular to the viewer

3) Right Side: Place signs on the rightside of the roadway whenever possible.Drivers are not conditioned to look to theleft side of the road for critical drivinginformation.

Signs placed on the right side of a roadway

An exception to this rule is the use of adouble-face Standard Identification signmounted parallel to a facility entranceroadway. This double-face sign would beused instead of two single-face signs,each mounted on the opposite right sidesof the approach road. Such a double-face sign should be sized and placed withclear target value and readibility from bothdirections.

Double-face Standard Identification sign

4) Distance Legibility: All signs must beclearly legible from the distance at whichthey are to be read. The Viewing Dis-tance Guide in this section shows theappropriate legend size for each type ofsign.

5) Advance Warning: Signs on roadwaysthat communicate a desired reaction,such as “Turn Right at Corner”, must beplaced in advance of the intersection toafford a safe distance for reaction to andexecution of the maneuver.

Sign placed well in advance of required action

Refer to Section 14, Lock, Dam andWaterway Signs, for guidance aboutplacing signs on a waterway to beviewed from both water and land.

Sign Placement (cont’d) EP 310-1-6a01 Jun 06

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6) Viewing Angle: Mount signs at eyelevel. The height of the average viewer’seye level is 5’6” standing, and 4’6” drivinga car. Eye level of a viewer driving a truckor recreational vehicle is higher. Signsplaced for viewing from long distances willbe mounted higher than those in theimmediate foreground. Mounting heightrequirements are shown in each sectionfor each specific sign type.

Pedestrian viewing

Vehicular viewing

Mounting height is measured from theground level to the bottom edge of thesign panel. For signs mounted alongroadways, the grade of the road isconsidered ground level. When ground-mounted signs on two posts are placed onsloping or inclined grades, adjustmentsmust be made to the post lengths andmounting heights. Extreme differencesbetween post lengths should be mini-mized whenever possible.

Post lengths adjusted for a grade slopingdown from the road

Post lengths adjusted for a grade sloping upfrom the road

7) Spacing: Signs must be located withrespect to other signs. Mounting sitesshould be carefully selected so thatgroups of signs are placed withoutcreating a cluttered appearance. Also,drivers must be given time to read andreact to one sign before another ispresented.

Signs spaced to allow driver to read and reactto each one independently

8) Sign Location and Site Preparation:Placement must be carefully consideredto ensure that each sign fits its locationand achieves optimum visibility. Signsshould be placed against a simple uniformbackground of a building wall, nativevegetation or open sky to reduce distrac-tion and visual confusion. Traffic signsand directional signs are normally locatedalong roadways or walkways and shouldnot receive any ornamental landscapingwhich would distract the viewer orobscure the sign. Avoid excessiveclearing or the need for continual groundsmaintenance, but it may be necessary todo some site work prior to placing a sign.

Standard Identification sign siting mayrequire special consideration of views orthe visual relationship with the namedproject area or structure. Where possible,an identification sign should be locatednear the entrance of the facility beingsigned. Carefully designed landscapingmay be permitted around StandardIdentification signs only. The siting andlandscaping of identification signs shouldbe reviewed by the district Sign ProgramManager and a district landscapearchitect.

Landscape planting may be permitted withStandard Identification signs. Thisplanting is ideally used to frame thebackground behind the sign, creating anorderly overall area view. Elaborate,domestic planting around the base of thesign is not recommended. A simple useof low growing ground covers around the

Field test to verify proper sign placement

9) Field Test: An effective way to deter-mine a sign placement location is to placethe actual sign in the proposed locationfor verification. This is relatively simplefor pedestrian signs; they are viewed fromrelatively short distances. For signsviewed from a moving vehicle, testing willinclude driving the approach from which itis viewed to verify the appropriateness ofthe proposed location. Since signlocation plans are usually prepared priorto the ordering of the actual sign, acardboard or brown paper banner, thesame size as the proposed sign, can beused to check placement against thecriteria above.

10) Breakaway Posts: Normally, signsshould be placed 14 to 16 feet from theouter edge of the shoulder, but no closerthan 6 feet from that edge. If there is noshoulder, signs should be no closer than12 feet from the edge of the traveled way.In areas where sign posts must be placedcloser than 12 feet from the edge of thetraveled way, the posts should be of asuitable breakaway or yielding design.Refer to Appendix B for more information.

sign with shrubs in the background isappropriate. Plants selected should benative or locally naturalized species thatblend well with their surroundings and donot visually compete with the sign itself.Effective plant selection should be usedto reduce maintenance.

Sign mounting methods have beenstandardized to create visual uniformityfor all signs placed around a facility.Mounting heights and locations havebeen determined for ease of reading.

There are two principal methods ofmounting signs. These are:

1) Ground-Mounted: Placing a signpanel on one or more posts fixed in theground.

Sign Mounting and PlacementEP 310-1-6a01 Jun 06

2-10

Ground-mounted with two posts

Ground-mounted with a single post

2) Wall-Mounted: Placing a sign on avertical surface such as the wall or doorof a building or fence.

Each type of sign utilizes a mountingmethod appropriate to the viewingrequirements. A sign must be positionedwith a clear line-of-sight from the viewingpoint to the sign face. General signlocations will be established on the signplan. Specific locations should be drawnon detailed site plans only after theplacement location has been field-checked for accuracy.

When a new sign replaces an old signthat does not comply with the standardsshown in this manual, the entire signassembly should be replaced. All oldsign bases should be removed and thesite cleared prior to the placement of thenew sign.

Wall- mounted

Mount signs using wood posts unlessotherwise specified. Wooden signpostsused consistently throughout a projectare visually more harmonious with thesurrounding landscape. They alsoprovide a more finished look to a signinstallation than metal posts. Thestandard for most small signs will be anominal 4” x 4” wooden post (No. 2grade or better, well-seasoned, treated,and free from defects). Larger signs maybe mounted with structural grade postsof larger dimensions.

Incorrect - New sign panel on old base

Correct - Appropriate mounting for this signtype

Sign Materials EP 310-1-6a01 Jun 06

2-11

Within each section there are recom-mendations concerning materials to beused for each category of sign. Thesematerials have been identified becauseof their proven suitability for theseapplications. Few of the materials orfabrication techniques identified in thismanual are exotic or proprietary, and themajority have been tailored to theirrespective uses and employ standardindustry practices and supplies.

Most project identification signs andthose signs placed in recreation areasand on waterways use the followingmaterials and fabrication processes:

- Plan section through HDO plywood oraluminum sign and post, with applied orscreen-printed legend on reflectivesheeting background:

- Plan section through a sign with routedand paint-filled legend:

Special-use signs are made from avariety of materials and reproductionprocesses suited to the requirements ofthe sign. For example: interpretive signscan be made from porcelain enamel;boundary markers from fiber-reinforcedpolyester; and building interior signsfrom injection-molded plastic with screenprinted legends.

All of the various alternatives are outlinedin the respective sections for each signtype. Assuming that all of the possiblematerials are equally appropriate,materials selection will be determined bythe following criteria:

1) Longevity: All of the materials identifiedhave a long life if properly maintained.

Reflective sheeting is guaranteed for

4) Material Legibility: A sign with a flatface is generally more legible than onewith a routed legend. Light createsshadows in routed letters that maylessen their legibility. Therefore, signsrequiring a consistently high level ofglance legibility (such as highwaydirectional and traffic control signs)should not be fabricated from routedmaterial. On the other hand, routedidentification signs may be placed atentrances and within projects where asmall percentage of legibility loss maybe sacrificed for the harmonious visualeffect created by the use of naturalmaterials.

Sign programs at most projects will usea variety of sign materials. The selectedmaterial will depend on the intendedfunction of the sign.

5) Other Materials: Substrate materialsnot mentioned in this manual may beconsidered for use. Check with the SignProgram MCX before using new materi-als.

6) Aesthetics: Regardless of signmaterial selected, the overall aestheticeffect of a project’s signage should be auniform and tailored look. Sign place-ment should reflect a sense of visualorder. Nothing is more visually chaoticthan too many signs placed randomly ina small area. Proper sign maintenanceis critical to upholding a high aestheticstandard. Finally, mounting materialsand heights shall be standardized forvisual uniformity.

It is essential to recognize that each signis part of a family of signs within a Corpsfacility, and as such the selection ofmaterials for each location shouldmaintain visual continuity.

In summary, to evaluate materials:compare the initial costs to materiallongevity; determine maintenance costsover time; and evaluate the overall visualeffect of all signs in the project. Keep inmind that aesthetic quality will dependmore on the appropriate use of materialsand the proper layout of typography thanon the amount of money spent on anindividual sign.

HDO or aluminumpanel

Reflective sheetingbackground

Reflective sheetingletter-forms

(scale of sheeting exaggerated)

Sign panel

Routed, paint-filledletter-forms

5-7 years and will generally last longer.Signposts that are not pressure-treatedmay need to be replaced on a shorterlife cycle, depending on environmentalconditions.

Though some signs may have to bereplaced due to damage and periodicupdating before the projected lifetime ofthe materials expires, using lowergrade materials than those recom-mended is ultimately more costly. Thisis because signs made with high gradematerials will need replacing less oftenthan signs made with inferior materialswhich deteriorate faster. The costdifference between the high grade andinferior materials is minimal becauselabor costs for fabrication and place-ment account for a significant portion ofthe overall expense.

2) Budget: Generally, the single mostexpensive sign in an area will be theStandard Identification sign. Because ofthe impression it will make over its 10-20 year life, this expense is justified.

Signs with custom legends will be moreexpensive than signs with the standardlegends shown in this manual.

The cost of the sign includes not justpurchase and installation, but also thecost of maintenance over its lifetime. Asign that costs less to purchase thananother may actually be more expensivewhen refinishing and replacementcosts are considered.

3) Maintenance Requirements: Themaintenance requirements of a signdepend upon the material chosen.Routed signs should be cleaned with amild soap on a regular basis. Reflec-tive sheeting signs will last between 7-10 years, but need to be cleanedroutinely. All recommended materialshave been chosen for durability andease of maintenance, but there arevariations. Assess the requirements ofeach possible material against themaintenance capabilities and costs at agiven site. All materials require somemaintenance: frequent, scheduledinspections are necessary to ensurethat they are in place and undamaged.All of the materials outlined in thismanual have been designed to bevandal resistant. Fabrication tech-niques such as the use of tamper-resistant hardware have been specified.However, no sign is completely vandal-proof. Some materials and methods ofconstruction are more resistant thanothers. Often a vandalism problem is

Sign MaintenanceEP 310-1-6a01 Jun 06

2-12

The maintenance of signs is an integralpart of comprehensive sign programmanagement. This includes inspecting,repairing, replacing, removing, cleaning,and refinishing. The effectiveness of thetotal sign system is only as good as themaintenance rendered. Missing, broken,or illegible signs cause confusion andaccidents and diminish the cumulativeeffect of the whole sign program. Poormaintenance reflects an attitude ofneglect, which in turn can lead to abuse ofan area and encourage vandalism.

A maintenance program begins with acomprehensive field inspection of allsigns. Use a site plan to locate signs,along with a sign schedule describing themessage, materials, mounting methods,and installation dates of each (seeSection 3, Planning). Establish a sched-ule and designate an individual to checkeach sign on the plan and evaluate thefollowing:

1) Is the sign in place?

Sign panel missing

2) Is the sign still necessary?

Redundant signs

3) Is the sign upright and facing in theright direction?

Sign facing in wrong direction

4) Are the supports in good condition?

Broken post

5) Is the face in good condition?

Missing letters

Bent face

6) Is the surface dirty?

Mildew or fungus

7) Is the sign obscured by foliage?

Leaves in front of sign

8) Is the sign in compliance with thismanual?

Sign not in compliance

9) Should maintenance work be re-quested to correct deficiency?

Following this evaluation, orders forremoval, replacement or maintenanceshould be prepared, and maintenancework done in a systematic manner. It isimportant that maintenance crews andpark rangers note damaged signs onmaintenance work orders as part of theirroutine work. The frequent scheduledinspections and routine observations arecomplementary, forming a total mainte-nance program. Appendix C outlines indetail the procedures necessary for acomprehensive sign maintenanceprogram. This information should beincorporated into the sign plan (seeSection 3) so that maintenance andreplacement are coordinated.

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The appropriate and effective communi-cations of safety-related information is akey component of the Corps SignStandards Program. Throughout allareas, including recreation facilities,waterways, locks and dams, constructionsites, and industrial facilities, safetysigns are used to restrict, warn andinform visitors and employees of immi-nent danger or possible hazardousconditions.

Because of the interrelationship of Corpsprojects and facilities, two different typesof safety signs may be used at the samelocation. This would be most common inand around a navigation lock whereWorkplace Safety signs are used alongwith standard waterway signs.

The Sign Standards Manual specifieswhich types of signs are to be used foreach different condition. If you havequestions concerning the appropriate typeor classification of sign to be used for aparticular application, consult your SignProgram Manager for assistance.

1) Sign Types:There are two basic types of safety signsused on Corps projects. These includestandard Workplace Safety signs asshown in Section 11 for use in Corpsshops and equipment, on a dam,powerhouse or locking device, andaround construction activity. The secondtype are public-oriented safety signsused at recreation projects and along thewaterway system as shown in Sections 7and 14.

The major difference between these twotypes of signs is the layout grid or graphicformat of the sign. Both sign types followthe established color system; i.e., red andwhite for Restricted and Danger signs,and yellow and black for Warning andCaution signs. For illustrative purposes,two symbol sign applications that arecommonly used are also shown as part ofthis review.

2) Sign Classifications:Although all safety signs share a commonfunction, there are differences as towhich classifications and types of signsare used for each particular condition.The illustrations shown on the followingpages identify both the sign classifications(Danger, Caution, etc.) and the varioustypes of safety signs within a specificclassification (recreation, waterway,workplace safety). The determination ofthe appropriate sign classification willdepend on the severity of the hazard.

3) Standardized Safety Sign Legends:Most commonly used safety-related signsare shown in the appropriate sectionsthroughout the manual. The legends forthese signs have been carefully devel-oped so that the signs will communicatethe intended message as effectively aspossible and maintain a common visualformat to increase the recognition value ofeach individual sign as used throughoutCorps facilities.

The Danger, Caution, and Warning safetysign legends appearing in this manualhave been approved by HQUSACE, Officeof Counsel, and cannot be changed. If thewording of a safety sign is not appropriateto the condition being signed, consult thedistrict Sign Program Manager. Requestsfor modified sign legends or a new signshould be made using the procedure andworksheet on page 1-13.

4) Legend System:A safety sign legend is made up of twoparts. These include a banner headlinewith signal word (Danger, Warning, orCaution) and a specific descriptive legend.Safety signs are placed to warn or instructviewers and have been worded in such amanner that the viewer is not endangeredin a hazardous location.

5) Signal Word:The headline banner shows a signal orkey word which designates the degree ofhazard and calls attention to the action/emphasis section below the signal word.It is always located in the upper section ofthe sign panel.

6) Specific Description:The action/emphasis section of a signcontains those words which state theappropriate protective action to be takenor clarify the nature of the hazard.

7) Sign Color:The sign classifications rely on colorassociations. This standard system ofsafety sign colors reflects acceptedindustry standards and should be main-tained as specified in this manual. Itmust be emphasized that Danger signsbe white on red and Warning and Cautionsigns be black on yellow to maintain thebasic integrity of the safety sign stan-dards. The basic colors for each sign aredescribed in the illustrations contained inthis review. Note that on Warning/Cautionsigns as used on waterways andrecreation sites, a chartreuse (ultra-brightretro-reflective Lemon Yellow color) isused instead of workplace Safety Yellow.

8) Scope:These standards apply to the design,application and use of signs intended toindicate hazards in the environment andprovide information so that injury orproperty damage resulting from suchhazards may be avoided.

9) Purpose:It is the purpose of these standards toreduce the proliferation of non-standardsigns and the use of a variety of signs toindicate similar hazards.

10) Sign Plan:Prior to placing any safety-related signs,they must first be made part of the projectsign plan. Legends must be reviewed forconsistency and their relationship to allother signs in the project.

11) Clarity and Legibility:All signs must adhere to the graphicformat and color system specified in thismanual. Legends should be brief and uselanguage that is easily understood by theviewing audience. The size of the signshall be determined by the size of theletters as required for a safe viewingdistance and by the length of the mes-sage.

12) Posting Policy:Unless signs are placed on a waterwaywith a long viewing distance, most safetysigns are relatively small and are placedfor viewing near the condition beingidentified. If the hazard covers a largearea, additional signs should be used.The sign must be readily viewed inrelation to the hazard.

Safety-related signs should be placed toalert and inform in sufficient time to avoidhazards or take appropriate action. Signsshould be so placed as to be legible,create no distractions or be hazards inthemselves. Care should be taken toavoid grouping too many signs together inone location. Do not place signs onmovable objects or adjacent to movableobjects such as behind a door, which,when moved, can obscure the sign.

13) Maintenance:Once a safety sign is installed, it must beproperly maintained until the hazard beingsigned no longer exists, or until a policydecision has been made by the district ordivision that the warning no longer beused. All safety-related signs must beinspected on a systematic basis andrepaired or replaced on a timely basis, asrequired.

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1. Danger/Restricted Signs These signs indicate immediate andgrave danger, a hazard capable ofproducing irreversible damage or injuryand prohibitions against harmful activity.

1.1 Recreation Sites To denote a hazard and identify specificprohibitions.

Typeface: Helvetica BoldLegend color: WhitePanel color: RedRule/bar: WhiteGrid format: 1

To indicate entry into a dangerous area asviewed from the water.

Typeface: Helvetica MediumLegend color: WhitePanel color: RedRule/bar: WhiteGrid format: 1

To prohibit watercraft entry into a danger-ous area with alternate banner “Re-stricted”.

Typeface: Helvetica MediumLegend color: WhitePanel color: RedRule/bar: WhiteGrid format: 1

In shops and around dams to identifyhazards.

Typeface: Helvetica BoldLegend color: White on red headline

and black on whitedescription

Panel color: WhiteRule/bar: Safety RedGrid format: A

1.2 Waterways

1.3 Waterways

1.4 Workplace Safety

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2. Warning/Caution Signs These signs are used to call attention to apotential danger, or a hazard capable ofresulting in moderate to severe injury ordamage. In some instances, the hazards maybe the same as those associated with Dangersigns but are of significantly less magnitude.

2.1 Recreation Sites To caution viewers about potential hazardousconditions.

Typeface: Helvetica BoldLegend color: BlackPanel color: Lemon YellowRule/bar: BlackGrid format: 1

To warn boaters approaching a hazardousarea.

Typeface: Helvetica MediumLegend color: BlackPanel color: Lemon YellowRule/bar: BlackGrid format: 1

In shops and around dams to warn of hazards.

Typeface: Helvetica BoldLegend color: Yellow on black bar, black on yellow panelPanel color: Safety YellowGrid format: A

Within a facility a symbol sign may be used inlieu of a safety sign as a more user friendlymethod to define specific rules at a location.Used with other symbol signs at the samelocation, these pictographs rely on a commongraphic shorthand for all prohibitions in publicareas.

Used at the entry to introduce prohibitions andsafety-related information for a facility.

Typeface: Helvetica BoldLegend color: WhitePanel color: Corps BrownSymbol: BlackCircle/slash Red on white backgroundGrid format: -

Used at specific locations where applicable inlieu of a written safety sign.

Typeface: Helvetica BoldLegend color: BlackPanel color: WhiteSymbol: BlackCircle/slash: RedGrid format: A

2.2 Waterways

2.3 Workplace Safety

3. Symbol Signs

3.1 Slat System withProhibition Symbol

3.2 Prohibition Symbol

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4. Notice Signs

These additional two classifications areused in the Workplace Safety sign format.They include “Notice” and general “Safety”information informing viewers of generalpractices, but should not be used in lieuof hazard warnings.

These signs are used to control or defineaccess and circulation. They are usedprimarily for information and are notplaced to identify a hazard.

4.1 Workplace Safety In shops and around dams to warn ofhazards.

Typeface: Helvetica BoldLegend color: White on Safety Blue

header with black onwhite panel

Panel color: WhiteGrid format: A

These signs identify rules and facilitiesrelating to health, first aid, medicalequipment, sanitation, housekeepingpractice and general safety information.

In shops and around dams to identifysafety practices.

Typeface: Helvetica BoldLegend color: White on Safety Green

header with black onwhite panel

Panel color: WhiteGrid format: A

5. General Safety Signs

5.1 Workplace Safety

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Foreword This report provides a guide on letter sizeand the placement of directional signs onroadways leading to, or in Corps recre-ation projects.

The primary references utilized in thisreport include the following:

• Geometric Design of Highways andStreets, by the American Association ofState Highway and TransportationOfficials (AASHTO), dated 1984.

• Manual on Uniform Traffic ControlDevices (MUTCD) Revision 4, by the U.S.Department of Transportation, dated1986.

Careful selection of letter size and signlocation will enable the motorist to detectand understand the sign message beforepassing the sign. There should be timefor the motorist to comfortably react to thesign message, to slow from the operating

Principals

Detection and Recognition Time

Viewing Distance

speed and then to turn at the appropriatecrossroad or access road. On multi-laneroadways, the motorist may have tochange lanes before slowing to thecrossroads or access road.

The information handling process of amotorist1 includes time periods for thedelay between the time a directional signis presented and the time the eyes beginto move, the eye fixation, and the recogni-tion or perception of the sign message.These times vary between two-thirds of asecond to six seconds2 depending on thecomplexity of the information and whetherit is expected or unexpected. A detectionand recognition time of up to three

seconds is recommended for signs onroad up to 70 miles per hour3 and a 3.0second time is used for general warningsigns4.

It is concluded from the informationpresented by AASHTO and the MUTCDthat a three-second detection andrecognition time would be appropriate fordirectional signs on roadways of allspeeds.

The viewing distance is the distance amotorist travels during the detection andrecognition time. This distance must beunobstructed and the directional signmust be within the motorist’s cone ofvision. The viewing distance in feet iscalculated by the following formula:

D = 1.47 TV

Where: D = viewing distance in feet T = detection and recognition time in feet V = operating speed in miles per hour

The operating speed is defined as the85th percentile speed (the speed at orbelow which 85% of the vehicles aremoving).

Letter Size The size of the upper case letters in thesign message consisting of upper andlower case letters is determined by themotorists ability to read the sign through-out the viewing distance.

Research in 19395 established a viewingstandard of 50 feet per inch of letterheight for daylight conditions and 40 feet

per inch for nighttime conditions. Thesevalues were for a static visual acuity of 20/20 and represented the 80th percentile ofthe distribution of the observed legibilitydistances. A 20/40 visual acuity is to beused for design to comply with FederalHighway Administration Standards sincedrivers licenses are commonly issued withthat minimum vision. Therefore, the

1AASHTO, Geometric Design of Highways and Streets, Washington D.C., 1984, p. 146.2Ibid, pp. 42-453Ibid, p. 1474U.S. Department of Transportation, Manual on Uniform Traffic Control Devices (MUTCD), Revision 4, 1986.5Forbes, T. W. and Holmes, R. S., Legibility Distances of Highway Destination Signs in Relation to LetterHeight, Letter Width and Reflectorization, H. R. B. Proceedings, Vol. 19, 1939, pp. 321-334

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Sign Placement

viewing standard for 20/40 vision wouldresult in a 25 feet per inch of letter heightfor daylight conditions and 20 feet perinch for nighttime conditions.

The research ophthalmologist workingwith the Corps on this project hasestablished a viewing distance for 28 feetper inch of letter height for HelveticaMedium typeface with upper and lowercase letters in the sign message for avisual acuity of 20/40. It is believed thatthis most recent research is moreapplicable for this project, but that aslightly larger letter size or smallerviewing standard be used to compensatefor nighttime conditions and for a dynamicvisual acuity.

Consequently, a standard utilizing aminimum letter height of four inches is

recommended for conditions withoperating speeds under 25 miles perhour and a minimum viewing standard of27.5 feet per inch of letter height. Amaximum letter height of 12 inches isrecommended for operating speeds of65 miles per hour and a viewing standardof 25 feet per inch of letter height. Theletter height size would increase by oneinch for each fives miles per hour above25 miles per hour.

It should be noted that the motorist with20/20 vision and an unobstructed viewingdistance would have twice the time toread the sign message than the motoristwith 20/40 vision. Therefore, it is alsorecommended that directional signs belocated where the sight distance wouldbe double the viewing distance.

The placement of directional signs is tobe far enough in advance of the locationof the site so that the motorist can reactand slow the vehicle or change lanes, ifnecessary, prior to reaching the appropri-ate crossroad or access road. In somecases, such as high speed highways,two signs may be necessary.

For conditions on a single lane approach,the minimum sign placement distance iscalculated to permit a motorist to comfort-able slow the vehicle prior to stopping orturning off the roadway approach. Thisdistance is calculated by the followingformula6:

D = ( ) x ( ) x 1.47

Where D = Distance in feetV2 = Operating speed in mphroadwayV1 = Final speed in mph atleaving roadway, assumed to bezero

However, AASHTO7 has indicated alonger distance traveled during a comfort-able deceleration than the formulaimplies. Because the AASHTO resultsuse longer distances than the calculated

V2 + V12

V2 - V16

V2 + V12

= Average speed during deceleration

V2 - V16 = Time required to comfortably

decelerate

6Woods, D. L. and Rowan, N. J., Street Name Signs for Arterial Streets, H.R.B. Record 325, 1970, p. 54.7AASHTO, p. 36 and p. 1044.

results, it is recommended that theAASHTO results be used for the minimumdistance a sign should be placed inadvance of the appropriate crossroad oraccess point.

It is common for some highway depart-ments to locate directional signs on ruralhighways one-half mile in advance of theappropriate crossroad. This is a desirablecondition and not the minimum condition.Therefore, a minimum and desirablelocation is recommended for the place-ment of directional signs. The minimumplacement would be used only when inurban areas or where the desirableplacement is not possible. In no caseshould the directional sign be placed lessthan 200 feet or more than 2600 feet fromthe appropriate crossroad or access road.A secondary directional sign may benecessary if the desired placement isused and the appropriate crossroadcannot be seen by the motorist whenapproaching the initial directional sign.The secondary sign would be located atthe minimum distance to the crossroad.

The minimum distance a sign is to beplaced in advance of the crossroad is to beincreased on multi-lane roadway ap-proaches. This also allows the motoristtime to change lanes. This distance isnormally traveled in approximately eightseconds in moderate to heavy traffic.Therefore, it would add approximately 200feet at operating speeds under 20 milesper hour and 800 feet at operating speedsat 65 miles per hour.

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Recommendations Table 1 contains the recommendedviewing distances, letter sizes, and signplacement for operating speeds up to 65miles per hour.

The decision to use a particular size signat a specific location should be made onthe basis of a thorough study of the area.Table 1 provides the fundamental criteriafor directional sign letter sizing andplacement.

Ambiguous and/or complicated situationsmay require a more indepth analysisperformed by a qualified engineer. Thisassessment is needed to exercise thejudgment inherent in the selection oftraffic signs just as it is needed to locateand design the roads and streets whichthe signs complement.

Table 1Directional sign letter size andplacement guide

Sign Placement Distance inAdvance of Location

Operating Detection Viewing Letter Single Lane Multi LaneSpeed* Recognition Distance Size Approach Approach

Time

(MPH) (Seconds) (Feet) (Inches) (Feet) (Feet)

0-20 3 90 4 200/600 400/90021-25 3 110 4 200/600 500/90026-30 3 135 6 250/600 600/90031-35 3 155 6 300/600 725/90036-40 3 180 9 375/1300 875/130041-45 3 200 9 450/1300 1000/130046-50 3 220 9 500/1300 1100/130051-55 3 250 12 650/2600 1400/260056-60 3 275 12 650/2600 1400/260061-65 3 300 12 725/2600 1550/2600

*Operating speed is the 85th percentile speed

Note: All dimensions have been roundedLegend: 200/600 = minimum distance/desired distance