30 BY MILES SUCCESSFULLY VIABLE, LESS TO COSTLY STRIPING FROM EMERGENCY A FEATURES. HORIZONTAL CALMING,

IN Roadway TRAFFIC ROBERT LIEU TRADITIONAL DETRIMENTAL TWO

PER Traffic TO OF LOW-COST ALTERNATIVES KAHN, ROADWAY CALMING CONSTRUCT, HOUR. THE TRADITIONAL TO SERVICES, ROADWAY REDUCE MORE ROADWAY P.E. VERTICAL! ALTERNATIVE IMPACT AND OPTION STRIPING THAN SPEEDS ARE AND DESIGN ALLISON

HAVE Calming

TRAFFIC Striping TO SEVEN LESS CAN IS AS A KAHN GOEDECKE, private way private cases, been duced California features. cal/tiorizontal that abilities service way calming public implemented tive dians, to humps, community features full/partial through he ment include INTRODUCTION implement • • • • • • In Traditional effective impacts is studies; have hour. Are one Are standard drainage; Have Can Can future emergency Provide Have striping design successfully lieti speeds a these of streets agency mini departments, viable, streets vertical cushions, The and can devices,

less recognized Option traffic the to successfully provide been of with Even no less

MBA as roadway changes; have many more to in and have traffic in costly features roadway they roadway may greater have displacement traffic calming adverse as as low-cost policies. detrimental documented local and traffic these on reducing positive services; greater a and a roadway bike/parking significant been result are not of chokers, installed roadways. been than traffic to

circles, a have closures. residents, and control by communities. the mented Can horizontal A redtice sometimes calming flexibility striping impact can construct; surface, be alternative alternatives implemented of local speed designed number results. traditional seven persons speeds consistent calming resulted striping potential include traffic diverrers, impacts chicanes, in be in devices; speeds benefits These While residents quickly. to alternatives reductions emergency techniques which some miles Southern lanes; In displace highway with and to of difficult calming to to insple option can These in many traffic speed road upon nega verti pub- meet road from these have with case cut- me and to dis per can re on be as a are slow USD particularly Traffic cost has calming vehicles techniques. reduced, striping traffic utilizing impression ing surface. vehicles, roadway. is TRAFFIC are displacement ALTERNATIVE TRAFFIC has calming many obtain local standard tions, public. derstood cost-effective may traffic have reductions, tives Southern quirements. lic ing Trttffic universally In Striping not street a the has tess to public be that been down major addition, residents. per calming roadway traffic operations. striping familiar calming They traffic control also greater disruption Emergency devices required option that down the by which standards. since This California. C’alfrnia have CALMING STRIPING installation implemented As that as been the out-of-the-area harrier These emergency which and roadway calming have is occurs calming manner a opposed recognized devices than been with type no TO striping speed local Devices there while traffic in are has roadway used striping While used in ITE emergency resulted Other many traffic vertical STANDARD to new to Traffic were service other JOURNAL been a The of Mantiat residents implemented certain within TECHNIQUES AS is for particular projects. (e.g., on or calming or emergency and devices. traveling the for to striping more considerably (CMUTCD) is service to cases. AN gives calming calming adversely in width public volume $2,500-$3,500 types desired traffic shown traffic by a installation speed in calming / are speed some or requirements a viable drivers the SEPTEMBER instances on some and the timely traditional horizontal the technique easily agencies. Roadway of has area streets roadway will vehicles calming calming (hiljbrm along fsunips) drivers, to alterna options humps driving by service travel reduc follow traffic traffic visual affect speed strip been slow who that 2011 and less not tin the re of to in a or speedcushions,the samesegmentof roadwaycanbe stripedforoniy$500 to $1,000USD.Anotheradvantageoftraf ficstripingas a trafficcalmingoption is futureflexibility.Trafficstripingcaneasily be changedin the future by sandblast ing the painted striping, if a particular installationisunsuccessfulin meetingits goalsor needs to be changed.further more,trafficstripingcanbeimplemented quicklythrough conventionalconstruc tiontechniquesbyexistingin-housepub licworksstaffor contractservices. Another significantbenefitof traffic stripingisthat it doesnot adverselyaffect drainage.Manytrafficcalmingdevicessuch asspeedhumps,roadwaychokers/curbex tensions,medians,and chicanescan ad verselyaffectroadwaydrainage.Thesede vicescanconstrictnormaldrainagepatterns Figure1.Typicaltrafficcalmingstriping. withinthe roadwaysurface,which could affectdrainageforthe roadways.This can result of the reduced speed.The strip be a two-wayleft-turnlane,whichpro requireadditionalroadwaymaintenancefor ingalternativescanconsistofaddingthe ‘ides left turns from the roadwayto the localpublicworksdepartments. following: adjacentpropertiesor acrosstheroadway Trafficstriping as a traffic calming • Centerlinestripe; itself.Anotheroption for reducingroad devicecan effectivelyreducespeedson • Edgelines; way width is striping chokers or chi a roadwaycThis is particularlyeffective • Centerlineplusedgeline; canes.Thesecanbe stripedwith a white on long, straight roadwayswhere there • Stripedmedian; 8-inchchanneltoprovidethedelineation are wide travellanesfor long distances. • Stripedchokeror chicane; of the chokeror chicane.Althoughnot Before-and-afterspeed surveysby RK • Striped speed hump without the as prominentas the raisedcurbingof a EngineeringGroup,Inc.,withtvhichthe raisedspeedhump; and typicalchokeror chicane,it doesprovide authorisaffiliated,haveshownthatspeed • Psycho-perceptivestriping. someof the sameoperationalfeaturesas reductionsin the range of one to more theraisedcurbingforchokersorchicanes than sevenmilesper hour are easilyac Centerlinestripingconsistsofadding byrequiringthedriverto slowwhiletrav complishedthroughroadwaystriping,es a typicaldouble-yellowcenterlinestripe elingthe trafficcalmingarea. peciallyforwidelocalstreetswitha curb- orsingle-dashyellowlinein the roadway Another trafficcalmingoption is to to-curbwidth of 36 to 40 feet.Another Thisseparatesthe directionoftrafficand provide“striped” speed humps across advantageof roadwaystripingis that it reducesthe roadwaywidth of the travel theroadway.Thesecanbeeffectivewhere canprovideforbikelanesorparkingareas lane to the driver. White 4-inch edge normal speedhumps cannot be imple adjacentto the travellanesaspart of the lines can be added to the right and left mented, such as a hilly area or where “completestreets”system.Thesebikeor side of the roadwaywherethere is suf gradesexceed8 percent.While limited parkinglanesareusedto definethe vari ficientwidth Ibrthe 8-footparkinglane. operationaldata is availableon this type ous functions0f the roadway:not only The parking lane can be providedand of striping, it can give the impression vehiculartravelbut alsovehicleaccessto separatedbythe4-inchwhiteedgeline.A of a speed hump in the roadwayarea, the neighborhood,parking,and accom combinationofboth centerlineandedge thereforeslowingvehicles.“Psycho-per modationsforothermodesoftransporta linestripingisthe mosteffectivemethod ceptive” stripinghas also been used in tion, suchasbicycles. of reducingthe overalltravelwaywidth conjunctionto implementationof speed of the roadways.This can be provided humps. This type of striping is shown STRIPINGALTERNATIVES on typicallocalstreetsand will provide in CMUTCD (figure 3B - 31). Smaller There are numerousstripingalterna for 10-12foot travellanesand 7-8 foot stripes are provided, initially going to tivesthat can be used for trafficcalm parkinglanes.A sampleof this designis largerstripeswhenapproachingthe traf ing.The basicconceptof trafficcalming shownin figure 1. ficcalmingdevice.A photo of this type stripingisto reducethe driver’sperceived Anothermethodofreducingtheroad of stripingis includedin Figure2. The width of the roadway.Bydoingthis, the waywidth isby providinga striped me evaluationof the effectivenessof optical driverstendto reducespeedandmayalso dian. The median can be providedby speedbarswaspresentedin the Novem be divertedfrom a particularroute as a double-yellowcenterlinestripes or can ber2001 (EricMeyers)and March2009 lIEJOURNAL/ SEPTEMBER2011 31 (StevenP.Latoski)issuesof ITE Journal. Thesestudiesdid showpromisingresults in speed reduction with these types of pavementmarkings.

TRAFFICCALMINGSTRIPINGCASE STUDIES RKEngineeringGroup,Inc.hasbeen involvedin severalcasestudies involv ingtrafficcalmingstripingasan alterna tivetrafficcalmingdevice.Thesestudies havebeenprimarilycompletedforprivate communities;however,tile privateroad waysand streetswereconstructedto city standards.In nearlyallcases,theroadways were36- to 40-footcurb-to-curbwidth and in many caseswere long, straight streets,whichencouragedspeeding.The Figure2.UCIexampleofpsycho-perspectivestriprng. implementationoftrafficcalmingstriping effectivelyredticedspeedon these road waysand had a positivereceptionby the communityand localagencies,including emergencyservicedepartments.

caseStudyNb. 1 Uuiie2005—June2006) The NewportRidgeNorth Commu nityisa manned—gatedcommunityin the cityofNewportBeach,California,USA. The community consistsof high-end, single—familydetachedhomes,which are servedbyaprimarycollectorroad(Cam bordRoad).ChambordRoadisa 40-foot cctrh-to-curbroadwaywith sidewalkson both sidesof the street.The roadwayis oriented in a north-south direction (as shownin figure 3) and has a length of approximately1.31miles. The steep grades along Chambord did not allowfor typicaltrafficcalming techniques,suchasspeedhumpsor speed cushions.In addition,thecommunitytvas concernedwith the constructionofthese typesof trafficcalmingdevicesand their effectson trafficoperationsand vehicle damage.Therewasalsopedestrianactiv itynearthecommunityrecreationcenter and poollocatedat thecenterportion of ChambordRoadandacommunitytennis courtfacilitylocatedon the north end of the street. Photosof Chambordbeforethe traf ficcalmingstripingwasimplementedare shownin figure4.Thiswide40-footcurb- to-curb street with an undefined travel wayencouragedspeedingthroughoutthe Figure3. NewportRidgeNorth,NewportBeach. roadway.Beforethe implementationof

32 ITEJOURNAL!SEPTEMBER2011 trafficcalmingstriping,the 85th percentile speedalongChambordrangedfrom45 to 47 milespet hour, and the averagespeeds rangedfrom 40 to 41 milesper hour. Traffic calming striping was imple mented alongthe entirelengthof Cham bord. This included a double-yellow centerline and 4-inch edge line stripes 8 feet from the curb face.After the traf fic calming striping was implemented, the 85th percentilespeedwasreduced to 37 to 39 milesper hour and the average speeddecreasedto 35 to 36 milesperhour throughout the length of Chambord as shown in Table 1. Figure4.ChambordRoadbeforerestriping.

case StudyNo. 2 Table1.Before-and-afterspeedsurveys. (August2005—December2007) Traffic calming striping was imple 85th%Speed mented in south Orange County within BeforeTraffic AfterTraffic the city’ofSanClemente,California,USA Calming Calming at the ReserveCommunity Association. Location Roadway Striping(mph) Striping(mph) This projectconsistsof a largenumber of single-detachedfamilydwellingunitswith Case Study #1 • ChairilmrdN/C Rivay 46 37 Newport Ridge North a recreationcenterlocatedin thesouthern • (hamh d S/C) Musset 47 39 portionofthecommunity.The projecthas (Newport Beach) . ( hainbord S/C) Batyeinon ‘15 39 fourelectronicgates,whichprovideaccess Case Study #2 • Montana del Sol to an adjacentarterial highway (Camino 23 22 The Reserve N/O Carnino Vera Ctuz Vera Cruz). This community had four (San Clemente) • ColinaRodante roadwaysserving a series of cul-de-sacs 32 30 throughout the community, both north S/C Carnino Vera Cruz Calle de Los Arbolea and south of Camino VeraCruz. 27 26 The main roadwaysservingthe com N/C)_Camino_Vera_Ctuz munity’sotith of Camino VeraCruz were . Calle de Los Arboles 34 33 40-foot curb-to-curb width streets and S/C_Camino_Vera_Cruz those roadwaysservingthe northerlysec CaseStudy#3 • EagleCreek W/O Indigo 37 31 OakCreek(Irvine) tion of thecommunityhada curb-to-curb . EagleCreekWit) Palm Wood 38 27 width of36 to 38 feet.Existingtrafficvol Case Study #4 • GardenTerrace E/O Hedgewood 31 30 umeand speedswerecollectedthroughout SummitatTurtle the communitybeforetrafficcalmingwas • CrestTerrace N/C BlueSummit 29 29 Ridge (Irvine) implemented.The 85th percentilespeeds . CanyonTerrace 33 31 rangedfrom23 to 34 milesperhour prior N/C Cezaisne_Valley to the implementation of traffic calming . ValleyTerrace 30 28 striping.Before-and-after85th percentile S/C)_Climbing_Vine speedsaresummarizedin Table 1. Summitatilirtle GatdenTerraceNit) SummitPark 31 30 Traffic calming striping consisted of Ridge (Irvine) Crest TerraceW/O Summit Park 29 29 adding double-yellow centerlines and white 4-inch edge lines on the wider . Canyon ‘I’erraceN/C SummitPark 33 31 roadwaysand the striping of edge lines ValleyTerraceN/C) SummitPark 30 28 for narrowerroadways. only the The 85th . SummitParkDrive at Valley lerrace 46 44 percentile was reduced to some degree Summit Park Drive after the implementation of trafficcalm 44 44 W/C \riew Terrace ing striping. The 85th percentilespeeds . StimmitParkDrive were reduced to 22-33 miles per hour, 43 42 E/O_Garden_Terrace with some minor reductions after the implementation of the striping.The SummitParkDriveatGardenTerrace 39 39

ITEJOURNAL/ SEPTEMBER2011 33

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of

oF at thesetypesofroadways(i.e.25-32mph), 12 then only minor speed reductions can be obtained by trafficcalmingstriping. 11 Wherespeedsaresignificand)’higher(i.e., more than 35 mph), then much greater 10 , / speed reductionscan be achievedfrom trafficcalmingstriping. H COMPARISONTOOTHERTRAFFIC r, CALMING TECHNIQUES kp 5ØId The use of traffic calming striping comparesfavorablyto other trafficcalm 6 ingtechniques.Althoughspeedredtiction canvaryfrom siteto site,positivespeed reductionscan be anticipatedwith the trafficcalming,dependingon thespecific roadwayconfigurationsand thewidthof travelway.Therearesignificantprosand 2 constoalltypesoftrafficcalmingdevices, assummarizedin Table2. As can be seen from Table2, traffic U calmingstriping can typicallyresult in .1 25: speed reductionsof approximately’one 20 3) 35 4Q 15 50 to sevenmilesperhourdependingon the Btori, 85th4 Speed (mph) situation.Speedhump and speedcush ions have considerablespeed reduction Figure5. Speedreductionwithtrafficcalmingstriping. capabilitiesof approximately8 milesper hour. Chokersand clsicanescan reduce devices.Anytimethat theverticalor hori emergencyservicevehicles,which have speeds3 to 6 milesperhour,andmedians zontaldisplacementof the roadway’sur an indirectimpacton safety. and pavementtexturecan resultin 2 to faceoccurs,thereisa potentialforvehicles Speedcushionshaveasimilareffecton 3 milesper hour redtiction.When there goingout of control,hitting objects,or safetyasspeedhumps,However,theycan are situationsthat requirespeed reduc otheractionswhichcouldbedetrimental he traversedbetterby largervehicles,in tions on localroadways,trafficcalming to the safetyof the driverand passengers cludingemergencyservicevehicles,which stripingcanbeconsideredthefirststepin of the vehicle.furthermore, impactsto can travelthroughthe speedcushionsat the trafficcalmingprocess.Moreaggres emergencyservicevehiclescanindirectly a normalspeedas opposedto a typical sivetrafficcalmingdevicessuchasspeed affectsafetywhen respondingto emer speedhump.Thisisa majoradvantageof humps/speedcushions,chokers,chicanes, gencyevents. speedcushionsoverspeedhumps. medians,and pavementtexturescancost Generally, traffic calming striping Chokerscan affectsafetyif they are considerablymorebut can be utilizedin minimizessafety considerations,since hit by vehicles.Propersignageand pave theeventthat the trafficcalmingstriping they followstandard trafficengineering ment markers are necessaryto ensure is not successfulin reachingthe speed- practices pursuant to the CMUTCD. that this does not occtir. Chokers can reductiongoalsset bythe community. Driversare familiarwith these typesof improvesafetyforpedestriansby provid trafficcontrol featuresand respondac ing a shorterwalkingdistancefor cross COSTCOMPARISON cordingly.This is true not onlyfor local walks.Chicanes,similarto chokers,can One of themajoradvantagesoftraffic residentswhoarefamiliarwiththe traffic have a safety’impact if a vehiclestrikes calmingstripingisits cost.Not onlycan calmingimplementedin an areabut also themwhiletraversingthroughthe traffic trafTiccalmingstripingbe implemented for drivers from outside the area that calmingdevicearea.Implementationof lessexpensivelythanmanyotheroptions, are unfamiliarwith the trafficcalming sharpcurb-widthtransitionscanresultin but it alsocan be modifiedor removed installations. vehiclecollisionwiththecurb,causingve without majorcostimplications.An ap Speedhumpsdo reducevehiclespeed hicledamageandpossibleout-of-control proximatecostcomparisonofvarioustraf if properlydesignedand whenadequate vehicleoperations. ficcalmingdevicesisincludedinTable2. signage/pavementmarkingsareprovided. Medianshavebeenshownto improve Speedhumpscan havean adverseaffect safetybyseparatingthedirectionof travel SAFETYCONSIDERATIONS onsafety—butonlyifdriversignorethem ofvehicles,However,whenimplemented There are numeroussafetyconsider andifreducedspeedsdo notoccur.Speed in onlyselectiveareas,vehiclescanhit the ations for implementingtrafficcalming humps can also reduce traveltimes for endsof medians,causingdamageto the

ITEJOURNAL/ SEPTEMBER2011 35

36

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to to vehicles,driver/passenger,and can also calmingstripingis not permanent and causevehiclesto goout ofcontrol.If me can easilybe changedif requiredin the diansarenot properlydesigned,theycan future.As a result of this, trafficcalm ROBERTKAHN, causewater to flowinto the pavement. ingstripingcanbelesscontroversialthan BE. ispresidentofRK This can causepavementdeterioration morerestrictivedevices. EngineeringGrotip, and iossof controlofvehicles. Inc. uehichisaf dl Pavementtexturehas limitedimpact CONCLUSIONS servicetransportation on safety,althoughvehiclescan possibly RKEngineeringGroup,Inc.hascom engineeringfirm located losetraction,dependingon the type of pleteda reviewof trafficcalmingstriping in NewportBeach, textureduringwetconditions.Pedestrians asan alternativeto verticalor horizontal california, USA.Mr crossingon pavementtexturecantrip or displacementtrafficcalmingdevicesstich Kahnhasmorethan 40yearsofprofessionalex slipdependingon thepavementtypeand asspeedhumps,speedcushions,chokers, perienceand hasownedhisownconsultingfirm condition.In addition,pedestrians(espe medians,pavementtextures,and other for 23years.Heisa registeredengineerin the ciallychildren)maynot seethe textured roadwaydesignfeatures.Trafficcalming statesofcalifornia,Colorado,and Nevada.Mr pavementasa part of the “street,”which stripinghasbeenshownto reducespeeds Kahnhasbeeninvolvedin thepracticeoftraffic makethemlessawareof traffic. effectively’asa firststepof a trafficcalm calmingsincetheearly1980s,whenhedesigned Mini trafficcirclescan causevehicles ing process.Striping is a low-costtraf souseofthefirstspeedhumpsin OrangeCounty.

to hit the curbsor causeotheraccidents. ficcalmingsolutionthat canhavemajor California. Hecurrentlyteaches“fundamen Also,ifsuchtrafficcirclesarenotproperly benefitsto the communitycomparedto talsof 7aflicEngmeertng”forthe Umsiversity designed,truckscanhavea difficulttime other vertical/horizontaldisplacement ofcaliforniaand hasbeena guestlecturerat navigatingthe intersectionand couldhit trafficcalmingdevices,yet stillprovides the Universityofcalifornia, Irvine.Mi: Kahn objectsin the roadway, substantialbenefitsin termsof reducing receivedhis3.S.and itI.S. in civilengineering Trafficcalmingstripinggenerallyhasa trafficspeedson the roadways. from the Universityof California,BerkeleyHe is positiveimpactfroma trafficsafetystand In conclusion,trafficcalmingstrip afellowofJTE. point. Traffic calmingstripingshouldbe ing is an effectivemeasurein a traffic! implementedpursuant to theCMUTCD transportationengineer’stoolboxoftraffic ALLISONKAHN requirements withrespecttolocation,type, calmingdevices.Theseroadwaystriping GOEDECKE, andplacementofthestriping.Whereused techniquesfollowstandarddesignprac MBAisa project astransitions,stripingshouldbeproperly tice, which reducesfuture tort liability. managerwithRKEngi designedbasedupon the operatingspeed Trafficstripingis a cost-effectiveand ef ileeringGroup,Inc.She ofthevehicleson that segmentroadway’. ficienttrafficcalmingmethodthatcanbe showedherfirst interest implementedquicklyto reducespeedson in thetransportation COMMUNITYACCEPTANCE roadways. • L field aftercompleting The community acceptanceof any a report,titled “RedLight,GreenLight,“about trafficcalmingmeasureiscriticalin long- Resourcesfor further information herfather rolein helpingcommunitiesasa term implementationand effectiveness. 1.CityofColoradoSprings,TrafficCalming transportationengineerbackin 1981.Allisonhas The vastmajorityof the professionallit Handbook.2003.Accessibleat www.springsgov. nowworkedasa seniortransportationplanner eratureindicatesthatatleasttwo-thirdsof comlfiles/TCHandbook.pdf. for morethan 12years,focusingonpreparing the communitymust support the traffic 2. Remington & Vernick Engineers, Old trafficImpactstudiesfor cousmercial,inc/its calmingtechniquesin orderfor them to NewarkTrafficcalming Plan. 2002. Accessible trial, institutional,and residentialprojects.She be implementedwithin the community, at www.wilmapco.org/Newark/Newark_traf_graduatedPhi BetaKappafrom Universityof In manycases,verticaland horizontal fic_calming.sectlPOE California,Irvine,receivedherMBAfrom Pep displacementof trafficcalmingdevices 3. Brown, Steven (Fehr Peers),City of La perdineUniversityand didpostgraduateueorkat areheavily’resistedby the localcommu HabraPafficManagementProgrttm.2006.Acces Os.fordUniversitySheisa memberofAmerican nity and drivingpublic.This is one of sibleatwww.lahahracitycom/article.cfm?id=191. PlanningAssociation(APM. the major advantagesof trafficcalming 4. Ewing,Reid, TrafficcalmingStateof the striping,sinceit is readilyacceptableto Practice.Washington,DC: ITE/FHWA. 1999. thelocalcommunitybecauseit isalready 5. DelawareDepartment ofTransportation. implementedon mostroadwaysthrough DelawareDepartmentof TransportationTraffic out communities.Trafficcalmingstrip calming Manual. 2000. Accessibleat ing is understoodby’the drivingpublic deldot.gov/information/pubs_forms/manuals/ throughoutlocalcommunities.It causes traffic_calming/pdF/deldotfinal.pdf. little damageto vehiclesand drivers/pe 6. Gulden, Jeff Reid Ewing. “NewTraffic destriansof the community.It doesnot CalmingDeviceof Choice.”ITEJournal,Vol79, adverselyeffectthe operationof vehicles No. 12,(December2009):26-31.Washington, for emergencyserviceagencies.Traffic DC: liE. 2009.

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