Plug-inHybrid&ElectricVehicleResearchCenter

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ReoccurringandIndirectIncentivesforPlug-inElectric

Vehicles–AReviewoftheEvidence

September2017

ScottHardman

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ReoccurringandIndirectIncentivesforPlug-inElectricVehicles–AReviewoftheEvidenceScottHardman*1*shardman@ucdavis.edu1Plug-in Hybrid and Electric Vehicle Research Center, Institute of Transportation Studies,UniversityofCalifornia,DavisAbstractMorethan2millionplug-inelectricvehicles(PEVs)havenowbeensoldtoconsumersglobally.Theadoptionofthesevehiclesisbeingpromotedbypolicymakersduetothemhavinghighefficienciesandzerotailpipeemissions.Thismeanstheycancontributetowardsreducingharmfulemissionsandresourcedepletion.ToencourageconsumerstopurchasethevehiclespolicymakersareutilisinginterventionsthatincreasetheconvenienceandlowerthecostofowningaPEV.GovernmentsareinvestinginPEVrecharginginfrastructure,allowingPEVstouseHOV,busortransitlanes,providingparkingincentives,givingPEVstollfeewaivers,allowingPEVstopaylowerannualroadtaxes,andareusingdisincentivessuchprogressivevehiclefueltaxes.TheaimoftheseinterventionsistoencouragemoreconsumerstopurchasePEVs.TherearenownumerousstudiesintheliteraturethatinvestigatetheimpactoftheseincentivesonPEVadoption.Nostudyhasreviewedthesestudieswiththeaimofreachingaconclusiveunderstandingregardingtheeffectivenessoftheincentives.Thisliteraturereviewthereforeconductsasystematicreviewoftheliterature.TheresultofthisisanunderstandingofwhichpolicymeasuresareandarenoteffectiveinpromotingPEVadoption.Theseconclusionsallowpolicyrecommendationstobemadewhichcanhelppolicymakersunderstandwhichincentivesshouldbeusedandhow.

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1. IntroductionTheintroductionofplug-inelectricvehicles(PEVs)whichincludesfullbatteryelectricvehicles(BEVs)andplug-inhybridelectricvehicles(PHEVs)isimportanttohelpsolvetheissuesofurbanairpollution,globalclimatechange,andfossilfuelresourcedepletion.Theirsuccessfulmarketintroductionmaybedependentongovernmentsprovidingincentivestoconsumers.Theseincentivesareneededtoconvinceconsumerstopurchasethevehiclesratherthancontinuingtopurchaseinternalcombustionenginevehicles(ICEVs).GovernmentshaveintroducedfinancialpurchaseincentivesandreoccurringincentivesinthehopethatthemarketuptakeofPEVswillincrease.Financialpurchaseincentivesincludeeconomicmechanismssuchasrebates,incometaxcredits,purchasetaxexemptions,andgrants.TheeffectivenessoftheseonincreasingPEVmarketuptakewasexploredin(Hardmanetal.,2017).ThatpreviousreviewfoundthatfinancialpurchaseincentiveshaveledtoincreasedadoptionofPEVs.ThereviewdidnotconsideranyotherincentivesalthoughtheauthorsdidconcludethatfinancialpurchaseincentivesalonemaynotbesufficienttopromotePEVsalesandthereforetheyneedtobepairedwithotherincentives.Thatreviewdidnotoutlinewhattheseotherincentivescouldbenordiditexploretheefficacyofanyoftheseincentives.Thereisnostudycurrentlypublishedwithintheliteraturethatexploresthissubject.A2016reviewattemptedtounderstandinfluentialfactorsinthepurchaseofanelectricvehicle(Liaoetal.,2016).Thatreviewaimedtounderstandalldifferentfactorsincludingpurchaseincentives.Theauthorsinvestigatedhighoccupancyvehicle(HOV)laneaccess,freeparkingandtollexemptionsbutwereunabletostatewhetheranyoftheseincentiveswereeffective.Thiscurrentreviewaddstotheliteraturebyassimilatingtheresultsofallpreviousstudiessothatanin-depthunderstandingofhoweffectivetheseincentivesareinpromotingPEVsalescangained.ThisresultsinaclearunderstandingofwhichreoccurringincentivesareeffectiveinincreasingPEVsalesandhowtheseincentivesshouldbeusedtohavethemostsignificantimpact.

1.1. IntroductiontoIndirectIncentivesThispaperconsiderstheimpactofseveralreoccurringincentivesforPEVs.IncludedinthisreviewarestudiesthatconsidertheimpactofPEVaccesstoHOV,busandtransitlanes,thedevelopmentofrecharginginfrastructure,parkingincentives,tollfeewaivers,annualroadtaxexemptions,andgasolineprices.Theavailabilityoftheseincentivesdiffersbetweennationsandevenwithinnations.Table1showsabreakdownofwhichnationshavetheseincentivescurrentlyinoperation.Thetableshowswhethertheincentivesareavailableacrosstheentirenationoriftheyareavailableonlyinsomeregions.Eachoftheseincentivetypesaredescribedbelow.

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HOV,busortransitlanes

Statefundedinfrastructure

ParkingIncentives

Tollorroadchargeexemptions

Annualroadtaxincentives

Progressivefueltax

Canada ○ ○ China ○ ● ○ ○ France ○ ● ● ●Germany ○ ● ○ ○ ● ●Japan ● ○ ○ ●Netherlands ○ ● ○ ● ●Norway ● ● ● ● ● ●Portugal ○ ● ○ ● ●Sweden ● ● ●UnitedKingdom ○ ● ○ ○ ● ●

UnitedStates ○ ● ○ ○ ○●:Availablenationwide○:Availableinsomeregionsonly

Table1:BreakdownofincentivesavailableinthetopmarketsforPEVs.

1.1.1. HOV,BusorTransitLaneaccessHOVlanes,buslanes,andfasttransitlanesarealllaneswithrestrictedaccess.HOVlanesareonlyaccessibletovehicleswith2ormoreoccupants.Therulesrestrictingtheiraccessaresometimesonlyinoperationduringpeaktraveltimes.Forexample,inNorthernCaliforniaHOVlanesoperateMonday-Friday6am-10amand3pm-7pm.SomeHOVlanesareinoperation24hoursperday7daysperweek,suchastheHOVlanesinSouthernCalifornia(Caltrans,2017).HOVlanesaresometimescalledcarpoollanesor2+lanes.Buslanesarelanesthatareusuallyonlyaccessibletobusesorcoaches.Insomecasestaxis,motorcycles,orcyclistscanaccessthelanes.Somenationshave‘prioritylanes’or‘fasttransitlanes’theselanesareoftenrestrictedorrequirepaymenttouse.HOV,bus,andtransitlanesarecommoninmanycountries.VeryfewcountrieshaveintroducedincentivesthatallowPEVstousethelanes.CurrentlyCanada,China,France,Germany,Netherlands,Norway,Portugal,theUnitedKingdom,andUnitedStateshavetheseprogramsinoperationforPEVs.OnlyinNorwayisthisincentiveavailablenationwidewiththeothernationshavingthisincentiveavailableonlyincertainlocations.

1.1.2. PEVChargingInfrastructureAvailabilityElectricvehiclesarepartiallyreliantonthedevelopmentofrecharginginfrastructuresothattheycantraveldistancesbeyondtheirrange.IntheearlyintroductionofPEVsprivatecompaniesmaynotbemotivatedtodevelopthisinfrastructure.ThisisduetolowreturnsoninvestmentswhichisassociatedwiththelownumberofPEVsthatwouldusetheinfrastructure.ManynationalandregionalgovernmentsaredevelopingpublicelectricvehicleinfrastructuretoencouragePEVmarketgrowth,theyarealsofundingthedevelopmentofprivateandworkplacecharginginfrastructure.Privatecompanieshavealsofundedtheinstallationtheirowninfrastructureanddevelopedtheirownchargingnetworks.InregionswithmorematurePEVmarketsprivatecompaniesareoperatingnetworksofchargerswhichconsumerpaytouse.SomeautomotiveOEMshavedevelopedtheirowninfrastructurenetworksforbuyersoftheirBEVstouse.SomecompanieshavealsoinstalledPEVchargingattheirofficelocationsforemployeestouse.Moststudiesintheliteraturethatinvestigatetheimportanceofrecharginginfrastructuredonotdistinguishbetweenprivate,public,OEMowned,andworkplacecharging.Thismeansthisreviewconsiderstheimportanceofalltypesofinfrastructurenotjustpublicallyfundedinfrastructure.StatefundedinfrastructuredevelopmentisunderwayinCanada,China,

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France,Germany,Japan,Netherlands,Norway,Portugal,UnitedKingdom,andUnitedStates.

1.1.3. ParkingIncentivesSeveralnationshaveintroducedincentivesthatenablePEVstoparkatareducedcostorforfree.Theseincentivesaremostcommonlyappliedinurbanareaswhereparkingissomethingthatconsumersalreadypayfor.FreeparkingforBEVshasbeenwidelyintroducedinNorwayforpublicparkingspaces.Inmostnationsthoughthisincentivediffersonaregionalbasis.IntheUSA,somecitieshaveintroducedtheseincentives.InSacramentoCaliforniaPEVscanparkforfreeorreceivea50%discountinmunicipalgarages.ParkingincentiveshavebeenintroducedinmanycitiesintheUSincludingLasVegas,NewYork,Boston,Denver,andSaltLakeCityamongstothers.Theyarenotavailablethroughoutthenationthough.InLondonPEVscanparkforfreeinseveralboroughs,thistypeofincentivedoesnotexistacrosstheUnitedKingdom,thoughthereareplanstointroducethisincentivein5morecities(DepartmentforEnvironmentandRuralAffairsandDepartmentforTransport,2016).InsomeregionsinGermanyPEVscanparkforfreeoncetheyhaveobtainedapermit.ParkingincentivesarebeingusedinChina,Germany,Japan,Netherlands,Norway,Portugal,UnitedKingdom,andUnitedStates.ThisincentiveisonlybeingappliednationwideinNorway.OftenfreeparkingforPEVsispairedwithPEVrechargingsothatconsumerscanchargetheirvehiclewhilstparked.

1.1.4. TollorRoadChargeExemptionsTollchargesarecommoninmanynations.Tollchargesareappliedonroadsorbridgesthatcanbeeitherpubliclyorprivatelyowned.Driversarerequiredtopayafeetoaccessthem.Themoneyisintendedtohelpfundtheconstructionandmaintenanceoftheroadinfrastructure.InsomenationsPEVscanaccesstollroadswithoutpayingafee.InNorwayPEVsdonotpaytollfeesonroads,bridges,andtunnels.Theypayreducedtollsonferries.InCaliforniadriversofPEVscanaccesshigh-occupancytolllanesorexpresstolllanesforfree.Congestionchargezonesareliketollroadsasdriversarerequiredtopayafeetodriveintheseareas.Thesearelesscommonthantollroadsthough.Congestionchargezonesmeanthatdriversmustpayafeewhentheydriveanywherewithinacertainarea.IntheUnitedKingdom,thecentralareaofLondonisacongestionchargezoneMonday-Friday7am-6pm.Duringthesetimesdrivers,mustpayafeeof£11.50perday.VehiclesthathaveCO2emissionslowerthan75g/kmdonotpaythecongestionchargefee.ThismeansthatallBEVs,mostPHEVsandsomeHEVsdonotpaythecongestioncharge.Similarly,inMilanolderICEVspayafeetoaccessacentralareaofthecity.NewICEVs,HEVs,andPEVscanaccessthezoneforfree.Bothtollandcongestionchargeexemptionsreducethecostofdrivingtocertainlocationsfordriversofvehiclesthatdonothavetopaythefees.Studiesintheliteraturethatinvestigatethesetopicsmakedistinctionsbetweenwhethertheyinvestigateatollexemptionoracongestionchargeexemption.TollandroadchargeexemptionsarebeingusedinChina,Germany,Japan,Norway,Sweden,UnitedKingdom,andUnitedStates.

1.1.5. AnnualRoadTaxIncentivesInsomenationsvehiclesarerequiredtopayanannualroadtax.Thistaxoccurseveryyearthevehicleisregisteredtobedrivenontheroad.MosttaxregimescalculatetheamountoftaxbasedonavehiclesCO2emissions,vehicleclass,and/orvehicleweight.IntheUnitedKingdom]vehiclespayanywherebetween£10-2,000(DependingonCO2emissions)for

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theirfirstyearofregistrationand£140eachyearafterthat(AsofApril2017).IntheUnitedKingdomBEVsareexemptfromthefirst-yeartaxandanysubsequentroadtaxes.InNorwayvehiclespayanannualvehicletaxthatisbasedonvehiclefueltypeandweight.Petrolanddieselvehiclesweighinglessthan7500kgpaybetweenNOK2,820(US$336)andNOK3,290(US$393).BEVspayareducedrateofNOK455(US$55)peryear.AnnualroadtaxincentivesforPEVsarebeingusedinFrance,Germany,Netherlands,Norway,Portugal,Sweden,andUnitedKingdom.

1.1.6. OtherSomegovernments,haveutilisedfinancialmechanismstoincreasethepriceofgasoline.Thesemechanismsareusuallyreferredtoasfueltax,fuelduty,orgastax.Fueltaxeswereintroducedasawayofcombatingairpollutionandclimatechangebyencouragingconsumerstopurchasemorefuel-efficientvehicles.Thoughthisisn’ttechnicallyanincentiveforconsumerstopurchaseaPEVitdoesdisincentiviseconsumersfrompurchasinganICEVinthehopetheypurchasemorefuel-efficientvehicles.Therefore,itcanbeusedasaninterventiontoencourageconsumerstopurchasePEVs.InmanyEuropeannationsfueldutymakesupasignificantproportionofthepriceofvehiclefuel.IntheNetherlandsfueldutyandtaxis70%ofthepriceof1litreoffuel.IntheUnitedKingdom,itisaround65%thecostof1litreoffuel.IntheUnitedStates,itisaround10-15%ofthecostofagallonoffuel.Studiesintheliteraturedonotonlyanalysetheeffectivenessofthesefueltaxes.TheyanalysetheimpactoffuelpricesonPEVsales.Therefore,theliteratureconsiderstheimpactoffuelpriceingeneral,notexplicitlytheimpactofincentives.Thesestudiesthereforeconsiderwillthereforebeimpactedbyincreasedinthecostofoilnotjusttaxincreases.ThesestudiescanstillbeusedtoinformpolicymakersasthedatawillshowhowtrendsinfuelpricearerelatedtoPEVsales.Forexample,ifhighfuelpricesareassociatedwithPEVsalespolicymakerscouldusethisinformationtofutureincreasethecostoffuelbyintroducinghightaxeswiththegoalofencouragingconsumerstopurchasePEVs.

OtherincentivesalsoincludeonesassociatedwithobtainingavehiclelicenceplateinChina.InShanghaiconsumerswantingtoobtainavehiclelicenseplate,whichisrequiredtobuyavehicle,mustbidforalicenceinanauction.Typically,only5%ofconsumersaresuccessfulinobtainingalicenceatauctions.InBeijingconsumers,mustenteralotterytoobtainalicenseplant.Usingthismethodonly0.15%ofconsumersaresuccessful.PolicymakershavemadeiteasierforbuyerofPEVstoobtainlicenseplantsintheseregions.InBeijingbuyersofBEVsreceiveaplateforfreewithoutneedingtotryandbidinanauction,thereforeitismoreconvenientandrequiresnofinancialexpenditure.InShanghaiconsumerswantingtopurchaseaBEVoraPHEVreceiveafreelicenceplatewithouthavingtheenterthelottery(Wangetal.,2017).

2. LiteratureReviewTheexistingliteratureanalysesHOVlaneaccess,butlaneaccess,fasttransitlaneaccess,workplacePEVcharginginfrastructure,publicPEVcharginginfrastructure,freeparking,discountedparking,preferentialparking,andtollandcongestioncharges.AnumberstudiesincludeanalysisontheimpactofgasolinepricesonPEVmarkets.Table2showsabreakdownofthestudiesusedinthisreview.Thetableshowsthemethodsusedineachstudy,whichvehiclestheyconsider,theregionofanalysis,andtheincentivesconsidered.25studiesinvestigatetheHOV,busorrapidtransitlanes,19studyPEVinfrastructuredevelopment,15parkingincentives,10tollorroadchargeexemptions,5investigateannual

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roadtaxreductions,4includegasolinecostintheiranalysis,andthereare2studiesthatconsiderotherincentives.

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IncentivesConsidered

Authors Methods VehicleType Region HOV,Busor

RapidTran

sit

Lane

StateFund

ed

Infrastructure

Parking

Incentives

TollorRoa

dCh

arge

Exem

ptions

Annu

alRoa

dTax

incentives

Other

Conclusions

Aasness,M.A.,&Odeck,J.(2015) CaseStudy PEVs Norway � � �

Tollexemptions,buslaneaccessandfreeparkinghavehadapositiveimpactonPEVadoption.Howeverrevenuefromtollandparkingfeeshasdroppedandbuslanesaremorecongestion

Adepetu,A.,Keshav,S.,&Arya,V.(2016)

Agentbasedmodel PEVs California � �

ThepresenceofworkbasedchargingdoesleadtoslightlyincreasedratesofPEVadoption

Ajanovic,A.,&Haas,R.(2016)StatisticalAnalysis PEVs

USA,EuropeandChina � � �

Freeparking,buslaneaccess,availabilityofchargingandzeroemissionzonesarethemostimportantfactorsinpromotingPEVs

Bakker,S.,&JacobTrip,J.(2013)

Workshopswithpolicymakers BEVs Europe � � �

Infrastructuredevelopmentisthemostimportant,freeparkingcanbeusedasatemporarymeasure,buslaneaccesscanalsobeusedtoincreaseBEVsales

Bjerkan,K.Y.,Nørbech,T.E.,&Nordtømme,M.E.(2016)

QuestionnaireSurvey BEV Norway � � �

TollfeewaiversfollowedbyfreeparkingandbuslaneaccessarethemostimportantfactorsinpromotingPEVs

Bonges,H.A.,&Lusk,A.C.(2016) CaseStudies BEVs USA � ImprovingaccesstoinfrastructurewillincreasePEVratesofadoption

Clinton,B.,Brown,A.,Davidson,C.,&Steinberg,D.(2015)

StatisticalAnalysis BEVs USA �

Resultsinconclusiveduetolimitedvariationinvariablesoverthetimeofthestudy

Diamond,D.(2009)StatisticalAnalysis HEVs USA � �

HOVlaneaccessisthemostsignificantinthestateofVirginia.Itislesssignificantinotherstates.HEVadoptionismostrelatedtoincome,gaspriceandvehiclemilestravelled

Egbue,O.,&Long,S.(2012)QuestionnaireSurvey BEVs USA �

Developinginfrastructurewillreducebarrierstoadoption.Educationthroughsocialmediaandstandardmediachannelswillalsohelp.

Figenbaum,E.(2016)Multi-LayerPerspective BEVs Norway � �

BuslaneaccessandtollexemptionshavebeenimportantinattractingbuyerstoBEVs

Figenbaum,E.,&Kolbenstvedt,M.(2016)

QuestionnaireSurvey PEVs Norway � � � � �

TollexemptionsarethemostimportantfactorforadoptersofPEVs,freeparkingissecond,workplacechargingisthird.Buslaneaccessistheleastimportantforadopters

Hackbarth,A.,&Madlener,R.(2013)

DiscreteChoiceAnalysis AFVs Germany � � �

Consumersarewillingtopayanextra€1620-3280forvehicleswithfreeparkingandbuslaneaccess

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Hardman,S.,&Tal,G.(2016) Interviews BEVs California � � �

High-endBEVbuyerspurchasefortechnological,environmentalandperformancemotivations.HOVlaneaccess,workplacechargingandfreeparkingarenotmotivationalfactorsbuttheydoincreaselikelihoodofrepeatpurchases

Hoen,A.,&Koetse,M.J.(2014)

QuestionnaireSurvey(StatedChoiceExperiment) FCVsandPEVs Netherlands � � �

FreeparkingandbuslaneaccessmaystimulateAFVadoption.Thefindingsarenotstatisticallysignificantthough.Buslaneaccessmaybemoreimportant.

Javid,R.J.,&Nejat,A.(2017)StatisticalAnalysis PEVs California � �

DevelopingcharginginfrastructureandraisinggaspricescanhelppromotePEVsales

Krause,R.M.,Carley,S.R.,Lane,B.W.,&Graham,J.D.(2013)

QuestionnaireSurvey PEVs USA � �

AwarenessofincentivesistoolowforthemtohaveanimpactonconsumerinterestinPEVs

Kurani,K.,Caperello,N.,Tyreehageman,J.,&Davies,J.(2014) Workshops PEVs California � � �

AdoptersvalueHOVlaneaccesswhentheyarelocatedneartothem.Freeparkingisvaluedifitisavailable.FreeworkandpublicchargingisalsovaluedbyPEVowners.

Liao,F.,Molin,E.,&vanWee,B.(2016)

LiteratureReview BEVs � �

Noconsensuswithintheliteratureonwhetherfreeparkingorfreechargingiseffective.

Lieven,T.(2015)

QuestionnaireSurvey(StatedChoiceExperiment) BEVs Global � � � �

Someconsumersvalueonlyfinancialincentives,someonlycharginginfrastructureandsomevalueallincentivesthatareavailable

Lutsey,N.,Slowik,P.,&Jin,L.(2016)

StatisticalAnalysis PEVs USA � � �

ThereisastatisticallysignificantrelationshipsbetweenPEVmarketshareand;vehiclemodelavailability,consumerfinancialincentives,publiccharginginfrastructure,workplacecharginginfrastructure,HOVlanesandthenumberofpoliciesbeingusedtheregion.

Mersky,A.C.,Sprei,F.,Samaras,C.,&Qian,Z.(Sean).(2016)

StatisticalAnalysis BEVs Norway � � �

BEVinfrastructure,beingneartomajorcitiesandincomearethemostsignificantpredictorsofBEVmarketshare.

Nicholas,M.a,&Tal,G.(2013)

QuestionnaireSurvey BEVs California �

WorkplacechargingcanincreasePEVsales.Itcanhavenegativeeffectsifchargersbecomecongested.

Nicholas,M.A.,Tal,G.,&Turrentine,T.S.(2016)

QuestionnaireSurvey&VehicleDataMonitoring PEVs California � WorkplacechargingcangreatlyincreaseeVMTforPHEVs.

Ozaki,R.,&Sevastyanova,K.(2011)

QuestionnaireSurvey HEVs UK � � �

FreeorpriorityparkingandexemptionfromLondonCongestionChargeareeffectiveincentives.

Percoco,M.(2014)StatisticalAnalysis AFVs Italy �

CongestionchargeincreasesthenumberofNGVs,HEVsandbi-fuelvehiclesandreducespre-euro4ICEVuse

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Plötz,P.,Gnann,T.,&Sprei,F.(2016)

StatisticalAnalysis PEVs

USAandEurope � �

PEVadoptioniscorrelatedtoincome,gasolineprice,thepresenceofin-directincentivesandthenumberofchargingstations

Sangkapichai,M.,&Saphores,J.-D.(2009)

QuestionnaireSurvey(StatedChoiceExperiment) HEVs California �

ConsumersareattractedtoHEVsduetotheirbeliefsrelatedtoenergy,airpollutionandhealthbutalsotheabilitytodriveinHOVlanes

Shewmake,S.,&Jarvis,L.(2014)

StatisticalAnalysis HEVs California �

HOVLaneaccessishighlyvalued.UsedHEVswithHOVstickersaremorevaluable.

Tal,G.,&Nicholas,M.A.(2014)

QuestionnaireSurvey PEVs California �

HOVlanesarevaluedbyconsumerswholiveinregionswithHOVlanesandwithhigherlevelsofcongestion.

Tal,Gil,MichaelA.Nicholas,ThomasS.Turrentine(2016

QuestionnaireSurvey PEVs California �

PEVswithHOVlanestickersarepurchaseonaverageforUS$1,400morethaniftheydonothaveasticker.

Tal.,G.&Xing.,Y.(2017)QuestionnaireSurvey PEVs California � LocalitytoHOVlanesisstatisticallyrelatedtoPEVadoptionrates

Tietge,U.,Mock,P.,Lutsey,N.,&Campertrini,A.(2016)

CaseStudiesusingstatisticalanalysis PEVs Europe � � �

FinancialincentivesalonearenotenoughtoencouragePEVadoptiontheyshouldbepairedwithno-financialincentivesforexampleHOVlaneaccessanddevelopingcharginginfrastructure

Wang,Y.,Sperling,D.,Tal,G.,&Fang,H.(2017)

ShortCommunication BEVs China � �

FreevehiclelicensingisthemostimportantfactorforadoptionofBEVs.Exemptionfromroaduserestrictionsandpubliccharginginfrastructurealsohaveanimpact.

Zhang,Y.,Qian,Z.(Sean),Sprei,F.,&Li,B.(2016)

DiscreteChoiceModel BEVs Norway � � �

ChargingstationshavegreatesteffectonBEVsales,tollwaiversarealsosignificant.BuslaneaccessisnotdesirabletopotentialBEVbuyersastheyperceiveitascausingbuslanecongestion

Zheng,J.,Mehndiratta,S.,Guo,J.Y.,&Liu,Z.(2012)

Interviewswithpolicymakers PEVs China � � � �

Roadchargingexemptions,priority/HOVlaneaccess,freeordiscountedparking,infrastructuredevelopment

Table2:Tableshowingtheauthors,methodsuses,vehiclesandregionsofstudyalongwiththeincentivetypesconsideredandasummaryoftheconclusionsineachstudy.

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2.1. HOV,BusorTransitLaneAccessIntotal25studiesanalysedtheimpactthatHOV,bus,ortransitlaneaccesshasonPEVadoption.ThefirststudiestoinvestigateHOVlaneswerein2009(Diamond,2009;SangkapichaiandSaphores,2009).ThesestudiesanalysedtheimpactofHOVlanesonHEVsales.Thestudyby(Diamond,2009)usedstatisticalanalysistoinvestigatetheimpactofgovernmentincentivesonHEVsalesacrosstheUSA.TheyfoundstatisticallysignificantrelationshipsbetweenHEVsalesandHOVlaneaccessinthestateofVirginiabetween2001and2004.After2004,whenHOVlaneswereintroducedinalargernumberofstatestheyfoundthatHEVsaleswerebettercorrelatedtovehiclemilestravelled(VMT),householdincomeandfuelcost.(SangkapichaiandSaphores,2009)usedaquestionnairesurveyintheformofastatedchoiceexperimenttounderstandinterestinHEVs.TheyfoundthatinterestinHEVswasrelatedtoenergyuse,airpollution,health,gaspriceincreases,andHOVlanes.TheydiscoveredthatpeoplewholiveclosetoHOVlanesorwhotravellongdistancesaremoreattractedtoHEVs.

From2013onwardtheliteraturebegantoassesstheimpactofHOVlaneaccessonPHEVandBEVadoption.TheclearmajorityofthesestudiesinvestigatedPEVsalesinCaliforniaortheUSA.Intotal17studiesinvestigatedCaliforniaortheUSA.(Krauseetal.,2013)usedaquestionnairesurveytounderstandthegeneralpopulationsawarenessandknowledgeofPEVsandsomeincentivesavailabletothemintheUSA.TheyfoundthatawarenessofHOVlaneswasverylow,withonly2.8%oftheir2302respondentsbeingawareofthem.However,theyfoundthatifconsumerswereawareofHOVlaneaccess48%ofthemweremorelikelytoconsiderpurchasingaPEV.TheauthorswereunabletofindastatisticallysignificantcorrelationbetweeninterestinPEVsandthepresenceofnon-financialincentives.Theystatethatthisisduetolowlevelsofawarenessofthecurrentincentivemeasures.Therefore,ifconsumersaremadeawareofHOVlaneaccesslevelsofadoptionwouldincrease.AnotherstudyintheUSAinvestigatedtheimpactofHOVlaneaccessonPEVsalesinCalifornia(TalandNicholas,2014).Thestudyusedaquestionnairesurveytounderstandthebehaviourof3659consumerswhohadpurchasedaPEV.ThevehiclesincludedintheirstudywereNissanLeafBEVs,ChevroletBoltPHEVs,andToyotaPriusPHEVs.TheyfoundthatforsomebuyersofPEVsthebenefitofHOVlaneaccesswassosignificantthatitwastheonlyfactorintheirdecisiontopurchaseaPEV.ThestudyfounddifferencesintheimpactofHOVlaneaccessdependingonthevehicletypeandlocationofrespondents.TheauthorsfoundthatHOVlaneaccesswasagreaterinfluenceonPEVbuyerdecisionsinareaswithmoreHOVlanesandgreaterlevelsoftrafficcongestion.TheSanFranciscoBayareaandLosAngelesareheavilycongestedandhavemanyHOVlanes.HOVlanesareanimportantfactorforPEVbuyersinthoseareas(Figure1).Inadditiontoregionaldifferencestheauthorsfounddifferencesbetweenvehicletypes.TheyfoundthatHOVlaneaccesswasamoresignificantmotivatorforbuyersofPHEVswithlowdrivingranges.BuyersofToyotaPlug-InPriusPHEVswith11milesofrangeweremoremotivatedbyHOVlanesthanbuyersofChevyVoltPHEVswith38milesofrange.ThestudysuggeststhatHOVlaneaccessshouldbelimitedtoPHEVswithlongerdrivingranges.ThisisbecauseHOVlanescouldencourageconsumerstopurchasePHEVswithshorterelectricrangesratherthanoneswithlongerelectricranges.PHEVwithlongerelectricrangeshavegreaterenvironmentalandenergyrelatedbenefits(Nicholasetal.,2016).AnotherstudybytheseauthorsonthesamedatasetfoundthatmanybuyersofToyotaPlug-InPriusPHEVsdidnotplug-intheirvehiclesmeaningthatmanyoftheirvehiclemilesdrivenwerecompletedwith

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theuseoftheirICEV.DriversofChevyVoltPHEVswerefoundtoplug-intheirvehiclesmorefrequentlyandachievedmanymoreelectricvehiclesmilestravelled(Taletal.,2014).

Figure1:PercentageofrespondentsbylocationandvehicletypethatstateHOVaccesswasaprimarypurchasingmotivation(TalandNicholas,2014).

AstudyconductedinCaliforniainvestigatedusedcarmarketsforPEVs(Taletal.,2017).ThestudyanalysedthetransactionpricesforusedPEVs.ThisstudyidentifieddifferencesinpricespaidforPEVswithandwithoutHOVlanestickers,whicharerequiredforPEVstouseHOVlanes.ThestudyfoundthatconsumerswerewillingtopaymoreforaPEVthathadaHOVlanesticker.TheresultsrevealedthatPEVswithHOVlanestickersweresoldforanaveragepremiumofUS$1,400overnon-HOVlanestickerPEVs.ThissignificantwillingnesstopayforaHOVlanestickersuggeststhatHOVlaneaccessissignificantfactorinencouragingPEVsales.TheresultsofthisstudyalsoshowthatHOVlaneaccesscannotonlyencouragenewPEVsalesbutitisalsoeffectiveinencouragingusedcarbuyerstopurchaseaPEV.AfurtherstudyinCaliforniaby(TalandXing,2017)usedanestedlogitmodeltoanalysedatafromtheCaliforniatravelsurveyandaPEVsurveywith3881respondents.IntheiranalysistheyfoundthatdistancetoHOVlaneswascorrelatedtoPEVadoption.(Caperelloetal.,2015)heldworkshopsthatinvolvedbothearlyadoptersofPEVsanddriversofICEVsinCalifornia.TheworkshopsweredesignedsothatPEVownersandICEVownerscouldhaveanopendialoguewitheachother.ThisallowedtheresearcherstounderstandwhatquestionsICEVownershadaboutPEVsbutalsowhatbenefitsofPEVownershipthePEVownersvaluedthemost.TheyfoundthatsomePEVownersvaluedHOVlanesveryhighly.SomeworkshopparticipantsstatedthatHOVlaneaccesswasthesolereasontheypurchasedtheirvehicle.SomePEVownersonlysawHOVlanesasabenefitofownershipanddidnotbelieveitmotivatedthemtopurchasetheirvehicle.TheresearchersobserveddifferencesinhowPEVownersperceivedHOVlanesbasedonwheretheylive,agreeingwith(TalandNicholas,2014).(Caperelloetal.,2015)foundthatPEVownerswholivedinareaswithtrafficcongestion,suchasSanJose,valuedHOVlanesmorethanpeoplewholivedinareaswithlesscongestion.

(Lutseyetal.,2016)analysedPEVmarketsandpoliciesin50U.S.cities.Usingstatisticalanalysis,theyfoundthattherelationshipbetweenHOVlanesandPEVsaleswasstatisticallysignificant.In-depthinterviewswithhigh-endBEVadoptersconductedby(Hardman,2016)foundthatforthebuyersofTeslaBEVsHOVlaneaccesswasnotaprimarymotivator.Theyfoundthatonly1participantintheirstudyof39peoplestatedthatHOVlaneaccesswasa

24% 17%

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BayArea LosAngeles SanDiego Sacramento RuralAreas

NissanLeaf ChevyVolt ToyotaPlug-InPrius

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reasonforbuyingahigh-endBEV.Theyfoundthat14participantsbelieveHOVlaneaccesswasabenefitofowningahigh-endBEV.Accordingtotheseresults,HOVlaneaccesswasnotamotivationalfactorintheirdecisiontobuyaBEVbutitdidincreasethechancesofthesebuyerspurchasinganotherBEVinthefuture.

AEuropeanstudyusedworkshopswithpolicymakersin7regionstounderstandtheimportanceofHOVorbuslanes.TheyfoundthatpolicymakersbelievedHOVlaneorbuslaneaccesscouldbeusedtoencourageconsumerstopurchasePEVs(BakkerandJacobTrip,2013).(HackbarthandMadlener,2013)usedadiscretechoiceanalysistounderstandconsumerpreferencesforalternativefuelvehicles(HEVs,PHEVs,NaturalGasVehicles,BiofuelVehicles,BEVs,andFCVs)inGermany.Thestudycontained711respondentsandincludedfreeaccesstobuslanesforAFVsinthechoicemodel.Thestudyfoundthatconsumersarewillingtopayanadditional€1620-3280foravehiclethatcandriveinbuslanesandcanbeparkedforfree.AnotherstudyconductedinEurope,thistimetheNetherlandsconductedachoiceexperimentwithprivatecarbuyerstounderstandpreferencesforAFVs(HoenandKoetse,2014).ThestudyfoundthatbuslaneaccesscouldincentiviseAFVadoptioninurbanareas.Theyauthorswereunabletoconfirmthisatahighlevelofconfidenceduetotheresultsoftheirstatisticalanalysisnotfindingastatisticallysignificanttrend,althoughtheauthorsstatethatthereisapositivetrend.

Norwayhasreceivedinterestfromacademics,perhapsduetotherebeingsignificantprogressinPEVmarketdevelopmentinNorwayandbecauseBEVscandriveinbuslanes.(Zhangetal.,2016)conductedadiscretechoicemodelonasampleoftheprivatecarbuyersandbusinessbuyersinNorway.TheyinvestigatedtheimpactsofcarspecificationsandincentivesonPEVsales.ThestudyfoundinterestinBEVswascorrelatedtotechnologicaldevelopment,tollfeewaivers,andthenumberofPEVchargingstations.Theyfoundthatoftheseincentivesaccesstocharginginfrastructurewasthemostsignificantfactor.Thisstudyfoundthatbuslaneaccesswasnotanattractivefeatureintheirsample.TheyfoundthatpotentialPEVbuyersbelievebuslaneaccessisanundesirableincentive.Thisisduetorespondent’sconcernsthatbuslanescouldbecomecongestedwithBEVs.AnotherstudyonthedevelopmentofBEVmarketsinNorwayusedamixedmethodsapproach(Figenbaum,2016).Thestudyusedmulti-levelperceptivetheory,marketdatafrom1990-2016,anddataformaquestionnairesurvey.Fromthisdata,theauthorsfoundthatbuslaneaccessandtollexemptionscanattractconsumerswhoareunsureaboutBEVstothem.TheseconsumerswouldordinarilynotpurchaseaBEVduetothembeingunsureaboutwhetherthereareeconomicbenefitsduetothelowrunningcosts.Buslaneaccessandfreeparkingthereforecreatedanichewithconsumerswhovaluethesetwoincentives.Buslaneaccesswaseffectiveduetoitbeingatimesavingbenefitthatcanbeutilisedimmediatelybyconsumer.Buslanesservedanadditionalpurpose,thiswascreatinga‘displaywindow’forBEVs.ICEVdriverswouldnoticeBEVsusingbuslanes,thisincreasesawarenessofBEVsthusincreasingsales.AnotherstudyinNorwayconducedstatisticalanalysisondisaggregatedBEVsalesinordertounderstandwhichvariablesarecorrelatedtoBEVmarketdevelopment(Merskyetal.,2016).ThisstudyfoundthattheBEVmarketwascorrelatedtoaccesstocharginginfrastructure,localitytomajorcities,andincome.InthestudytollexemptionsandbuslaneaccesswerenotcorrelatedtheBEVmarket.Thiscouldbeduetothesetwovariablesbeingcorrelatedtothenumberofchargingstationsandlocalitytocitiesthemselves.Theauthorsstatethatfutureresearchisneededtohelpunderstandhowbuslaneaccess,tollexemptions,andfreeparkingrelatetoBEVmarkets.(Tietgeetal.,2016)investigatedPEVmarketdevelopmentsinEuropeusingcasestudiesof10cities.ThestudyfoundthatPEV

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marketswererelatedtothepresenceoffinancialincentivesandreoccurringincentives.TheystatethatthemosteffectivestrategytoencouragePEVadoptionistoundertakepromotionalactivitiesconsumeroutreach,andintroducelowemissionszonesandHOVlanes.(AasnessandOdeck,2015)revieweddatathatwasavailableatthetimeofundertakingtheirstudytounderstandwhichincentiveshavebeeninstrumentalinencouragingPEVadoption.Theyfoundthattollfeewaivers,buslaneaccess,freeparking,andpurchasetaxexemptionshaveallinducedconsumerstopurchaseaPEV.Theydonotethoughthattheseincentivescanalsohavenegativeeffects.InthecaseofbuslanestheyfoundthatPEVsusingtheselanescouldcausecongestionandmaketransitjourneytimeslonger.(FigenbaumandKolbenstvedt,2016)usedresultsfromaquestionnairesurveyof3111BEVusers,2065PHEVusers,and3080ICEVuserstogaininsightsintoBEVandPHEVadoption.Theyfoundthattransitlaneaccesswastheleastimportantincentiveforadopters,whovaluedfreeuseoftollroadsthemost.Finallyastudyby(Bjerkanetal.,2016)surveyedconsumerswhoownBEVsinNorway.TheyinvestigatedhowBEVadoptersranktheimportanceofincentivesintheirpurchasedecision.Theyfoundthatconsumersrankpurchasetaxandvatexemptionsthehighest,thesebeingacriticalfactorforover80%ofadopters.Accesstobuslaneswasfoundtobeacriticalfactorfor21%ofbuyers.ThisfactoralthoughvaluedbyalowernumberofconsumerisstillanimportantincentiveasiscanconvincebuyerswhoarenotmotivatedbyfinancialreasonstopurchaseaBEV.

ChinahasreceivedlittleattentionfromresearchersinvestigatingPEVadoptionandHOVortransitlanes.Thisreviewonlyidentifiedonestudyby(Zhengetal.,2012).Theauthorsconductedsurveyswithstakeholdersin10citiesinChina.Fromthesestakeholdersurveys,theyconcludedthataneffectivenon-monetarystrategytoincentiviseconsumerstoadoptPEVswastheuseofwhattheyrefertoas‘superiorlanes’.TheygiveHOVlanesasanexampleofatypeof‘superiorlane’.

2.2. PEVChargingInfrastructureThisreviewidentified19studiesthatinvestigatetheimpactoftheavailabilityofchargingstationsonPEVadoption.MoststudiesfocusontheUSandCalifornia.TheearlieststudythatinvestigatedtheimportanceofPEVinfrastructurewasin2012(EgbueandLong,2012).Thatstudyusedaquestionnairesurveytoinvestigate‘technologyenthusiasts’attitudesandperceptionstowardsBEVs.Thestudyinvolved481peopleandobservedseveralbarrierstotheadoptionofPEVs.ThemostnotableofwhichwastheshortrangeofBEVs.TheauthorsfoundthatthedevelopmentofPEVrecharginginfrastructurecouldhelptoremovethisbarrier.TheyalsostatethatincreasingBEVdrivingrangeswillcontributetoimprovingconsumerperceptions.Astudyby(NicholasandTal,2013)investigatedtheimpactoffreeworkplacechargingonPEVadoptioninCalifornia.UsingaquestionnairesurveyadministeredtoPEVadopterstheyfoundthattheprovisionoffreeworkplacechargingcanencouragePEVsales.ItcanalsocauseproblemsandcanleadtopeoplebeingdissuadedfrompurchasingaPEV.IfchargingstationsbecomecongestedconsumersmaybeunwillingtopurchaseaPEVduetothemobservingthisandperceivingitasabarriertopurchaseofaPEV.Theauthorssuggeststrategiestomitigatechargingstationcongestion.Theystatethatworkplacechargingstationsshouldbeeithermanylow-costlevel1orlevel2chargers,orfewerDCfastchargerswhichPEVdriverscanonlyuseforalimitedtime.TheysuggestthiscouldbedonebymakingconsumerspayforDCfastcharging,thiswaytheycouldonlychargewhentheyneedtodoso.TheyalsosuggestenforcingtimelimitsonhowlongDCfastchargerscanbeusedforbeforedriversneedtomovetheircarstoanewparkingspace.Thiswouldmitigatetheissueofchargepointcongestion.

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Theworkshopsconductedby(Caperelloetal.,2015),previouslymentionedinsection2.1,alsoinvolveddiscussionofBEVcharginginfrastructure.Thestudyfoundthatfreechargingcanbeabenefit.SeveralPEVownersintheirstudymentionedfreeworkplacechargingandfreepubliccharging.ThestudyfoundalowlevelofawarenessofPEVcharginginfrastructureamongstICEVdriversthough.Theyhighlighttheneedtoincreaseeducationandawarenessactivitiessothatmoreconsumersareawareofcharginginfrastructure.Anotherqualitativestudy(Hardman,2016)foundthathigh-endBEVadopterswerenotmotivatedtopurchasetheirBEVduetothepresencecharginginfrastructure.Thisisduetothesevehicleshavingdrivingrangesofmorethan200milespercharge,meaningthatpublicorworkplaceinfrastructureisusedlessfrequently.9outof39intervieweesdidbelievethattheuseoffreeinfrastructurewasabenefitthough,especiallyforlongdistancejourneys.

(Lutseyetal.,2016)includedpubliccharginginfrastructureaspartoftheiranalysisofPEVmarketsin50UScities.TheyfoundastatisticallysignificantrelationshipbetweenPEVmarketshareandthepresenceofpublicandworkplacecharginginfrastructurehighlightingtheneedforbothtypesofinfrastructure.Theyalsofoundrelationshipsbetweenvehicleavailability,thenumberofpolicyactions,thepresenceoffinancialincentives,andHOVlaneaccessaspreviouslymentioned.A2017studyanalysedtheCaliforniahouseholdtravelsurveyusingregressionanalysis(JavidandNejat,2017).TheauthorsusedthisdataalongwithassumptionsrelatingtothedemographiccharacteristicsofearlyadopterstoestimatePEVadoptionin58countiesacrossCalifornia.ThestudyfoundthatgaspricesandchargingstationspercapitaarerelatedtoPEVadoption.TheysuggestthattransportplannersshouldseektoincreasegasolinepricesandconstructchargingnetworkstopromotePEVmarketdevelopment.Casestudiesconductedby(BongesandLusk,2016)foundthatimprovingaccesstoinfrastructurewillleadtoincreasedPEVsales.TheymakerecommendationsonhowtoincreaseaccessbyimprovingthedesignofPEVchargingoutletsandparking.Theysuggestthatchargingoutletsshouldbeaccessibleby4parkingspacesratherthanjust1or2.

StudiesthatinvestigatePEVuptakeinEuropehavealsoworkedtounderstandtheimportanceofPEVcharginginfrastructure.TheNorwegianstudyby(Zhangetal.,2016)constructedachoicemodeltounderstandwhysomeconsumerswereattractedtoBEVsmorethanothers.TheyfoundthatagreaterdensityofcharginginfrastructurewouldleadtomoreconsumersbeinginterestedinpurchasingaBEV.AnotherNorwegianstudyanalysedregionalPEVsalesacrossNorway(Merskyetal.,2016).TheauthorsfoundthatmarketgrowthwascorrelatedtoPEVinfrastructure.AnotherstudyinNorwayusedaquestionnairesurveytounderstandseveralissuesassociatedwithBEVadoption.Theyfoundthataccesstoworkplacechargingandpublicchargingwereimportantforaround¼oftheir3111BEVrespondents.Astudyby(Plötzetal.,2016)usedregressionanalysistounderstandPEVsalesintheUnitedStatesandEurope.TheyfoundthatforEuropePEVsaleswereinfluencedbyincome,gasprice,andthepresenceofincentives.FortheUnitedStates,theyfoundthatgasprice,incentives,andthenumberofchargingstationspercapitainfluencedBEVsales.TheydidnotinvestigatetheimpactofchargingstationsforEurope.AnotherstudyinEuropedidincludeinfrastructuredevelopmentaspartoftheiranalysis.Thestudyconductedcasestudiesof10regionsinGermany,UnitedKingdom,France,Netherlands,andNorway.ThestudyfoundthattherewasacorrelationbetweenPEVmarketshareandthenumberofchargingstationsintheRegions.WorkshopsheldbyBakkerandTripinEuropefoundthatallpolicymakersrecognisedtheimportanceofPEVinfrastructureinencouragingPEVadoption(BakkerandJacobTrip,2013).

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TwostudieshaveanalysedtheimportanceofPEVrecharginginfrastructureinChina.Thefirstoftheseinvolvedsurveyswithstakeholdersin10Chinesecities(Zhengetal.,2012).ThesurveysaskedstakeholderswhatwasneededtoprogressthePEVmarket.ThestakeholdersstatedthatPEVcharginginfrastructureisneededalongwithfinancialincentivesandothernon-monetaryincentivessuchasfreeordiscountedparking.ThesecondstudythatlookedatChinawasashortcomminationby(Wangetal.,2017).ThisstudyexploredreasonsbehindthemarketgrowthofPEVsinChina.TheyfoundthatinadditiontootherincentivesrecharginginfrastructurecouldassistinthegrowthofPEVmarkets,thoughtheyfoundthatitwasnotthemostsignificantinfluencer.Themostsignificantinfluencerwasfoundtobefreevehiclelicensing,whichisdiscussedinmoredetailinsection2.6.

Onefinalstudytoassesstheimportanceofinfrastructureconductedglobalanalysisoftheissue.(Lieven,2015)usedachoicebasedmodeltounderstandthemosteffectivepolicymeasuresin20nationsacross5continents.Thestudyinvolved8147respondents.Theiranalysisrevealedthatworkplace,public,andfreewaylocationswereallneeded.Theyfoundthatchargingonfreewayswere‘musthaves’andthattheabsenceofthesecausesthehighestlevelofdissatisfactionamongstpotentialPEVbuyers.Theyfoundthatutilisationofthesechargingstationswillbelow,buttheyhelpinalleviatingPEVbuyersconcernsrelatedtorangeanxiety.Theyusedclusteranalysisintheirdataanddiscoveredthreeclustersdependingontheincentivesdemandedbyconsumers.Oneoftheclusters(22.6%)wasbuyersonlysensitivetofinancialpurchaseincentives,thesecondwasacluster(35.5%)ofbuyerswhodemandedmultipleincentives,andfinallythelargestcluster(41.9%)wasmadeupofconsumerswhodemandedfreewaychargingtobepresentiftheyweretopurchaseaPEV.

2.3. ParkingIncentivesWithintheliterature15studieshaveassessedtheimpactoffree,discounted,orpreferentialparkingforPEVs.ThefirststudytoinvestigatetheimpactofparkingincentivesonAFVadoptionwasa2011studythatlookedatHEVadoptionintheUnitedKingdom(OzakiandSevastyanova,2011).Theauthorsfoundthatfreeorpriorityparkingcouldbeaneffectiveincentive.ItwasespeciallyprevalentforpeoplelivingwithintheM25LondonOrbitalMotorway.ThiswasduetofreeparkingintheUnitedKingdombeingmostlyofferedasanincentiveinLondonandduetothehighcostofparkinginLondon.Theauthorssuggestthatfree/priorityparkingschemesshouldbemoreextensiveandexpandedtootherregionsoutsideofLondon.Theystatethattheseschemesneedtobepublicisedtobemosteffective.Thestatedchoiceexperimentby(HoenandKoetse,2014)foundthatfreeparkingisimportantinurbanareas.Thestudyby(Krauseetal.,2013)foundthatintheirsampleof2302consumers56%wouldbemorelikelytoconsiderpurchasingaPEViffreeparkingwasavailable.Howeveronly1.7%ofconsumerswereawarethatfreeparkingwasanincentivethatwasalreadyavailabletothem.ThestudyfoundthatfreeparkingcouldbemoreeffectivethanHOVlaneaccess,whichleadto48%ofconsumersbeingmorelikelytoconsideraPEV.Thediscretechoicemodelstudyby(HackbarthandMadlener,2013)includedfreeparking,buslaneaccess,andvehicletaxexemptionsaspartoftheiranalysis.Consumersarewillingtopay€1620-3280forthecombinedbenefitsoffreeparkingandbuslaneaccess.Theydonotbreakthisdownintotheindividualincentives.(Merskyetal.,2016)alsofoundthatparkingincentivesmaybeimportantduetothemfindingthatPEVsaleswerecorrelatedtolivingclosetomajorcitiesthathaveparkingincentives.ThreestudiesinNorwaybothfoundthatfreeparkingwasanimportantmeasurethatcanbeusedtopromotePEVsales(AasnessandOdeck,2015;Bjerkanetal.,2016;Figenbaumand

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Kolbenstvedt,2016).AfinalstudyinEuropefoundthatPEVparkingincentivesareaneffectivemeasure(BakkerandJacobTrip,2013).Thestakeholdersinthatstudybelievedthatfreeparkingcouldonlybeatemporarymeasurethough.InthecaseofcitieswithhighdemandforparkingstakeholdersbelievedthatICEVdrivescouldresentPEVdriverswhocouldparkforfree.StakeholdersdidnotwanttointroducetoomanyparkingspacesthatwereforPEVsonlyincasepublicsupportforPEVsfell.AnadditionalconsiderationwasthefallinrevenueduetofreePEVparking.Thiscouldcreateabudgetdeficitinsomeregions.Finally,onestakeholderbelievedthatPEVparkingshouldnotbefreeasthegoalofpolicymakersintheirregionwastoreducecaruseoverallandtoencouragetheuseofpublictransit.

SomebuyersofPEVsinCaliforniahavebeenfoundtovaluefreeordiscountedparking(Caperelloetal.,2015).Thiswasdependentonlocationthough.PEVownersinSanJose,CaliforniawerefoundtobemotivatedtopurchaseaPEVbecauseoffreeparking.However,participantsnotedthatthisincentivewasduetoexpireinthatregion.PEVbuyersinSacramento,Californiaalsovaluedfreeparking.Preferentialparkingwasvaluedformorereasonsbeyondthefinancialsavings.PEVadoptersindicatedthatitwasbeneficialnothavingtosearchforaparkingspaceastherewasusuallyanemptyPEVspace.(HardmanandTal,2016)foundthatfreeparkingwasonlyvaluedbyasmallnumberofconsumers.Thismayhavebeenduetothatsamplenotsamplingregionswherefreeparkingwascurrentlyavailableandbecausethegoalofthestudywasnottoinvestigatefreeparking.Thestudyby(AjanovicandHaas,2016)on14urbanareasinEurope,USA,andChinafoundthatfreeparkingwasoneofthemostimportantnon-monetarymeasuresalongwithbuslaneorHOVlaneaccess,charginginfrastructuredevelopment,andcongestionchargezones.Thechoicemodelby(Lieven,2015)foundthatfreeparkingwasattractiveforsomeconsumers,thoughfinancialincentives,andfreewaychargingstationsweremoreeffectiveinpromotingPEVsales.Finallythe2016reviewby(Liaoetal.,2016)wasunabletofindanyevidenceintheliteratureregardingfreeparkingoritsimpactonPEVadoption,theythereforecouldnotstatewhetheritwasorwasnotaneffectivepolicymeasure.

2.4. TollorRoadChargeExemptionsThereare10studiesthatinvestigatetheeffectivenessoftollandroadchargeexemptions.ThesestudieshaveconsideredNorway,UnitedKingdom,Italy,France,Netherlands,Germany,andChina.6studiesconsideredintheimpactoftollwaiversinNorway(AasnessandOdeck,2015;Bjerkanetal.,2016;Figenbaum,2016;FigenbaumandKolbenstvedt,2016;Merskyetal.,2016;Zhangetal.,2016).StatisticalanalysisofNorwegianBEVsalesfoundthatPEVsalesarenotrelatedtotollexemptions(Merskyetal.,2016).Theauthorsnotethatthismaybeduetocrosscorrelationsimpactingtheirresults.Thediscretechoicemodelconductedby(Zhangetal.,2016)foundthepresenceoftollwaiverscanincreaseBEVsales.Thestudyby(Figenbaum,2016)containingdatafromconsumerswhohavepurchasedaBEVfoundthattollexemptionswereeffectiveinattractingconsumerstopurchaseaBEV.InthesamewayasbuslaneaccessattractedconsumerstoPEVstollexemptionsdidthesamebyallowingbuyersofBEVstoreceiveimmediatefinancialbenefits,beyondfuelsavings.TwofurtherstudiesinNorway(AasnessandOdeck,2015;FigenbaumandKolbenstvedt,2016)alsofoundthattollfeewaiverswereeffectiveinpromotingBEVsales.ThestudybyFigenbaumandKolbenstvedtfoundthattollaccesswasthemostimportantreoccuringincentive.Finally(Bjerkanetal.,2016)foundthatexemptionfromroadtollswasacriticalfactorfor49%ofBEVbuyersinNorway.Thiswaslessimportantthanexemptionsfrompurchasetaxes,butmoreimportantthanfreeparkingandbuslaneaccess.This

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suggeststhatforsomebuyerstheexemptionsfromroadtollsarethemostimportantreoccurringincentive.TheauthorssuggestthatexemptionsfromroadtollsalongwithbuslaneacesaretheonlyincentivesthatconvincesomeconsumerstobuyaPEV.Theseconsumersarenotmotivatedbythefinancialincentivesappliedatthepointofpurchasemeaningthesereoccurringincentivesarecriticalinencouragingconsumerwhoaren’tfinanciallymotivedtopurchaseaPEV.

ThestudyofHEVadoptionintheUnitedKingdomfoundthatexemptingHEVsfromtheLondoncongestionchargehadasignificanteffectonHEVadoption(OzakiandSevastyanova,2011).ItwasespeciallytrueforconsumerslivingclosetoLondon.(Percoco,2014)investigatedtheimpactofroadcharginginMilan.RoadchargingwasintroducedinMilanin2008inthecentreofthecity.Atthetimeofthestudyalternativefuelvehicles(HEV,naturalgasandbiofuelvehicles)andICEVswithemissionscompliantwithEuro4standardsorabovecouldaccesstheroadchargezonesforfree.ICEVswithemissionslowerthanEuro4standardsmustpayafeeofbetween€2-10perday.In2012apartofthezonewassuspendedforaperiodof50days.Theauthorscouldrecordchangesintrafficcompositionduringthesuspensionandwhentheroadchargezonewasinfulloperation.Theauthorsfoundthattheroadchargezonehadapositiveeffectonthevehiclefleet,theyfoundthatdriversofICEVswithlowerthanEuro3emissionsswitchedtousingbio-fuel,naturalgas,orHEVs.(Tietgeetal.,2016)foundthattherewasarelationshipbetweentollroadsandPEVmarketshareinNorway.Intheirconclusions,theystatethatfinancialpurchaseincentivesarenotsufficientontheirowntodrivePEVadoption.Theyindicatethatnon-financialmeasuresareneededsuchaspreferentialaccesstoroadchargezonesandtollwaivers.SurveyswithPEVstakeholdersinChinafoundthatpolicymakerssupporttheuseoftollandroadchargeexemptionsasmeasurestopromotePEVadoption(Zhengetal.,2012).

2.5. AnnualRoadTaxIncentivesFewerstudieshaveanalysedtheimportanceofannualroadtaxexemptionsordiscountsforBEVs.Only5studiesinthisreviewconsideredthistypeofincentive.Apossiblereasonforthelackofliteratureonthistopiccouldbeduethisincentiveonlybeingavailableinfewareas.TheUSAwhichmuchoftheliteratureinvestigatesdoesnothavethisincentiveinplace.ThefirststudytoconsidertheimpactofannualroadtaxreductionswasthestudyonHEVadoptionintheUnitedKingdomby(OzakiandSevastyanova,2011).Thestudyfoundthatreducedrunningcosts,whichintheirstudyincludedreducedexpenditureongasolineandonroadtax,wasrelatedtotheadoptionofHEVintheUnitedKingdom.ThestudyfoundthatperceivedfinancialbenefitswerestronglyaffectthedecisiontopurchaseaHEV.(HackbarthandMadlener,2013)investigatedtheimportanceofannualroadtaxexemptionsforAFVsinGermany.TheyfoundthattheremovalofthisincentivewouldhaveasignificantimpactonAFVmarkets.TheiranalysisfoundthatifannualroadtaxwaiverswereremovedwillingnesstopayforAFVswouldfallby€2330-4700.Thestudyby(HoenandKoetse,2014)alsofoundthistobethecase.TheyfoundthatintheNetherlandsroadtaxexemptionsarehighlyvaluedbyconsumersandtheirremovalwouldhaveanegativeimpactonthemarket.TheyalsostatethatalthoughitisaneffectivemeasureitisexpensiveduetothelostrevenuefromPEVs.(Lieven,2015)foundthattaxincentivesareattractiveforPEVbuyers,theyfoundthattheyarenota‘musthave’butthepresenceoftheseincentivescanencouragemoreconsumerstoadoptPEVs.FinallyastudyofNorwegianBEVbuyersfoundthatannualroadtaxdiscountswereanimportantreasonforthepurchaseofaBEV(Figenbaum,2016).ThisstudyfoundthatroadtaxexemptionswereasignificantcontributortothepurchaseofaBEVfor49%ofbuyers.Thiswasthesecondmostimportantincentive

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behindtollexemptions.ThismeantthatinthecaseofNorwaytaxexemptionsweremoreimportantthanfreeparking,thepresenceofcharginginfrastructure,andbuslaneaccess.

2.6. OtherSeveralstudieshaveincludedtheimpactofvehiclefuelpriceintheiranalysis.SeveralofthesestudieshavefoundrelationshipsbetweenPEVsalesandgasolineprices.ThemajorityofthesestudieshavefocussedontheUSA(Adepetuetal.,2016;Diamond,2009;JavidandNejat,2017),onestudyinvestigatedboththeUSAandEurope(Plötzetal.,2016).ThefirststudyintheUSAconsideredtheimpactofgasolinepricesonHEVadoption(Diamond,2009).TheauthorsfoundthatthepriceofgashadthestrongesteffectonHEVmarketshare.Theystatethata10%increaseingaspricecouldleadtoa72-95%increaseinHEVmarketshare.(JavidandNejat,2017)foundthatgaspricesarealsorelatedtothesizeoftheBEVmarket.HighergaspricesaresignificantlyrelatedtoPEVmarketshare.TheysuggestthattransportplannerscouldincreasegaspriceinordertoencouragePEVadoption.(Adepetuetal.,2016)didnotfindanyevidencetosuggestthatgaspriceswereeffectiveinpromotingPEVsales.ThoughmostresearchdoesindicatethatincreasingpetroleumpriceswillleadtomoreconsumersadoptingHEVs,PHEVs,andBEVs.

Theshortcommunicationby(Wangetal.,2017)foundthatoneofthemosteffectiveincentivesforPEVadoptioninChinawastheabilitytogetafreelicenseplate.InsomeregionsinChinathereisasignificantwaitinglisttogetalicenseplate,whichisrequiredtopurchaseavehicle.Newcarbuyersmustwaitupto20monthsandpayonaverageUS$12,434foralicenseplate.ResultsfromasurveyinShanghaishowthat64%ofPEVbuyersstatethatthefreelicensewasthemostimportantfactorintheirpurchasedecision.FreeplatesforPEVsmeanthatthereisnowaittimeorfinancialexpenditure.Inadditiontothissomecitieshaverulesdictatingthedayswhichvehiclescanbedriven.InBeijingPEVsareexemptfromarulethatstatesvehiclescanbeonlydrivenontheroads1workingdayperweek.(Wangetal.,2017)statethattheseareeffectiveinincreasingPEVsales.

2.7. SummaryThereviewexaminedthefindingsof35studiesthatinvestigateindirectandreoccurringincentivesforPEVs.25ofthesestudiesinvestigatedHOV,busortransitlaneaccess,19infrastructuredevelopment,15parkingincentives,10tollorroadchargeexemptions,4gasolinecost,and5annualroadtaxes.AbreakdownofhowmanystudiesfoundtheseincentivestobeeffectiveinpromotingPEVsalescanbeseeninTable3.Thetableshowsthenumberofstudiesthatinvestigateeachincentivetypeandhowmanyoftheseconcludedthattheincentivewaseffective.ThereasonswhysomestudiesdidnotfindtheincentivesdidnothaveanimpactofPEVsalesisalsoshown.

Ofthe25studiesinvestigatingtheimportanceofHOV,busortransitlanes20foundthattheselanesareeffectiveinincreasingPEVmarketshares.5studieswereunabletostatethatHOVlaneswereeffectiveinincreasingPEVmarketshares.(Merskyetal.,2016)wereunabletodetectrelationshipsinPEVadoptionandHOVlaneaccessduetocrosscorrelationsintheirdatasetimpactingtheirresults.Buslaneaccesswasfoundtobeundesirableby(Zhangetal.,2016)duetorespondentsbelievingitwouldcausecongestioninbuslanes.Theliteraturereviewby(Liaoetal.,2016)wasunabletoidentifyenoughliteraturetofullyunderstandtherelationshipbetweenHOVlaneaccessandPEVsales.Thestudyby(Clintonetal.,2015)wasunabletodetectanytrendsbetweenPEVsalesandHOVlanesduetotheirbeingnotenoughvariationintheirdataset.MoststudiesfindHOVlanestobeeffectiveinpromotingPEVsales.Studiesusingstatisticalanalysis,statedchoice

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experiments,postpurchasequestionnairesurveysorinterviews,andstudiesconductingcasestudieshaveallfoundthatHOV,bus,ortransitlaneaccessforPEVsleadstoincreasedsalesofthevehicles(AjanovicandHaas,2016;BakkerandJacobTrip,2013;Caperelloetal.,2015;Chorusetal.,2013;Diamond,2009;Figenbaum,2016;HackbarthandMadlener,2013;Hardman,2016;Krauseetal.,2013;Lieven,2015;Lutseyetal.,2016;Nicholasetal.,2016;SangkapichaiandSaphores,2009;ShewmakeandJarvis,2014;TalandNicholas,2014;TalandXing,2017;Tietgeetal.,2016;Zhengetal.,2012).

All19studiesthatexploredtheimportanceofcharginginfrastructurefoundthatitwasanimportantfactorinincreasingthemarketforPEVs.Studiesthatusestatisticalanalysis,modelling,casestudies,interviewsandquestionnairesurveysallcametothisconclusion.StudieshavefoundthatcharginginfrastructureisanimportantfactorinpromotingPEVsalesinUSA(Adepetuetal.,2016;BongesandLusk,2016;Caperelloetal.,2015;EgbueandLong,2012;HardmanandTal,2016;JavidandNejat,2017;Lutseyetal.,2016;NicholasandTal,2013;Plötzetal.,2016),China(Wangetal.,2017;Zhengetal.,2012),Europe(Bakker,2010;Merskyetal.,2016;Tietgeetal.,2016;Zhangetal.,2016)andGlobally(Lieven,2015).Infrastructuredevelopmentisneededatworkplaces,publiclocationsandontravelcorridors.Somestudieshavefoundthatconsumersarenotawareofcharginginfrastructure.Educationandoutreachcampaignsshouldbeusedtopromotethepresenceofcharginginfrastructure.ThisshouldincreasePEVadoptionrates.

Thereare15studiescurrentlypublishedthatexploreparkingincentives.13ofthesefindthatfree,discounted,orpriorityparkingareeffectiveindrivingPEVadoption.Thestudyby(HardmanandTal,2016)didnotfindparkingtobeanimportantmotivationalfactorforhigh-endBEVsbuyersperhapsduetothesamplenotincludingadoptersofBEVsfromregionswherefreeparkingwasavailable.Thereviewby(Liaoetal.,2016)wasunabletoidentifyanyliteraturethatinvestigatedparkingincentives.Thestudyby(Lutseyetal.,2016)includedparkinginfrastructurein‘otherincentives’sodidnotbreakdownwhetherparkingwascorrelatedtomarketshare.Theiranalysisdidshowthatthepresenceof‘otherincentives’wererelatedtoPEVmarketsharesuggestingthatfreeparkingmaybeasignificantinfluenceonpurchasedecisions.Moststudiessupporttheeffectivenessofparkingincentives.Studiesfrom(AjanovicandHaas,2016;BakkerandJacobTrip,2013;Caperelloetal.,2015;HackbarthandMadlener,2013;HoenandKoetse,2014;Krauseetal.,2013;Lieven,2015;Zhengetal.,2012)havefoundthatparkingincentivesareaneffectivepolicymeasureinpromotingPEVuse.Authorshavenotedthatawarenessofparkingincentivesislowwhichimpactstheireffectiveness.ThereforepromotionalactivitiesareneededtoincreaseawarenesswiththeresultbeingincreasedPEVsales(Caperelloetal.,2015;Carleyetal.,2013).

Thereare10studiescurrentlypublishedthatinvestigatetheimpactoftollorroadcharges.MoststudiesinvestigatingthistopicconcentrateonNorway.ThisliteraturehasfoundthattollexemptionshavecontributedtothesuccessofPEVsinNorway(Figenbaum,2016;FigenbaumandKolbenstvedt,2016;Zhangetal.,2016).TherestoftheworldincludingthetopPEVmarketshasreceivedfarlessattentionwithjust1studyonChina(Zhengetal.,2012),1onUnitedKingdom(OzakiandSevastyanova,2011),1onItaly(Percoco,2014),and1onEurope(Tietgeetal.,2016).9outof10studiessuggestthattollandroadchargewaiversareeffectiveinincreasingPEVadoptionindicatingthattollandroadchargeexemptionsareeffective.

Only5studiesassessedtheimportanceofannualtaxexemptionsorreductions(Figenbaum,2016;HackbarthandMadlener,2013;HoenandKoetse,2014;Lieven,2015).4

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ofthosestudiesfoundthattheyareanimportantconsiderationinthepurchaseofaPEV.Oneofthesestudiesfoundthatitwasthemostimportantincentive,withanotherfindingthatitwasthesecondmostimportantincentive(Figenbaum,2016;HackbarthandMadlener,2013).ThissuggeststhatitisanincentivethatcanbeusedtopromotePEVsales.ToconfidentlystatethattaxincentivesareeffectiveinpromotingPEVsalesmoreresearchshouldbeundertaken.IncentivesInvestigated

NumberofStudies

Studiesfindingincentivetobeeffective

Reasonsbehindstudiesnotfindingincentivetobeeffective

HOV/Bus/RapidTransitLane

25 20 • Notenoughvariationindatasettodetectanyrelationships(Clintonetal.,2015).• Consumersplaceahighervalueonfreeuseoftollroads(FigenbaumandKolbenstvedt,

2016).• Literaturereviewunabletofindtrendsinliterature(Liaoetal.,2016).• Unabletodetectrelationshipduetocrosscorrelationsindataset(Merskyetal.,2016).• PotentialbuyersofPEVsconcernedaboutbuslanecongestion(Zhangetal.,2016).

InfrastructureDevelopment

19 19

ParkingIncentives

15 13 • Consumersseethisasabenefitbutnotapurchasemotivation(HardmanandTal,2016).

• Literaturereviewunabletofindtrendsinliterature(Liaoetal.,2016).Toll/RoadChargeExemptions

10 9 • Nostatisticallysignificantrelationshipindicatingthattollfeewaiversareeffective.Thoughthiscouldbeduetoneighbouringmajorcitiescontainingthoseincentivesimpactingtheresults(Merskyetal.,2016).

GasolineCost 4 3 • NoevidencetosuggestthatincreasinggaspricesresultsinincreasedPEVsalesaccordingtotheirmodel(Adepetuetal.,2016).

AnnualRoadTax 5 5

Other 2 2

Table3:Summaryoftheresultsofthisliteraturereview.ThetableshowsthenumberofstudiesthatinvestigateeachincentivetypeandhowmanyofthesestudiesfoundthatgivenincentivetobeeffectiveinincreasingPEVsales.Thefinalcolumnshowsthereasonssomestudiesdidnotfindeachincentivetobeeffective.

3. ConclusionThisreviewhasfoundthatreoccurringincentivesareeffectiveinencouragingmoreconsumerstoadoptPEVs.Theseincentivesshouldbepairedwithfinancialpurchaseincentivessothattheyhavethemostsignificantimpact(Tietgeetal.,2016).IntroducingmorereoccurringincentiveswillhaveagreaterimpactonPEVsales.TherolloutofPEVrecharginginfrastructureisthemostimportantfactorinincreasingPEVmarketshares.AllstudiesthatinvestigatedtheimpactofinfrastructurefoundthatitsdevelopmentdoesleadtomorePEVsales.Thisappliestostudiesthatinvestigatedpublic,private,andworkplacecharging.TherelativeimportanceofHOV,busortransitlanes,parkingincentives,tollandroadchargeincentives,annualroadtaxexemptions,andgasolinepricesisdifficulttorank.Studiesinvestigatingtheseincentiveshavegenerateddifferentresultsrelatingtotheirimportance.Thestudyby(Bjerkanetal.,2016)foundthatinNorwaytollfeewaiversarethemostimportantincentiveforPEVbuyers.Howeverastudyby(Merskyetal.,2016)foundnorelationshipbetweenPEVsalesandtollfeewaivers.Thistypeofcontradictioniscommonwithintheliteraturemakingitdifficulttoquantitativelyranktheimportanceofthesedifferentincentivetypes.EachincentivetypehasemergedasthemostimportantincentiveinpromotingPEVssalesindifferentstudies.Thereasonforthedifferencesbetweenstudy’sconclusionsisduetothedifferentmethodsused,thedifferentregionsstudied,alongwithdifferingprivatemotivationsofthePEVconsumersstudied.HOV,busandtransitlane

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accessforPEVsisthemostwidelyinvestigatedincentivewithintheliterature.MoststudiesfoundthatHOV,busandtransitlaneaccessforPEVsiseffective.Thisisreliantuponconsumerslivingneartoorusingtheselanes.Ifconsumersdonotlivenearthelanesnorusethemthisincentivewillnotbeeffective.IftheydoliveneartothelanesandusethemthisincentivecanbeinfluentialinpromotingPEVmarketgrowth.Parkingincentiveswerefoundtobeeffectivebymoststudiesthatanalysedtheirimpact.ParkingincentivesleadtoconsumersbeingmorewillingtoadoptaBEV,butonlyinareaswherethisincentiveisavailable.Thisincentiveismostcommonlyappliedinurbanareaswhereparkingisinhighdemandandcostly.TollandroadchargeexemptionshavebeeninvestigatedlessthanHOVlanesorparkingincentiveshave.Theliteraturefindsthattollandroadchargeincentivesareeffectiveonlyinregionswheretheseincentivesareinplace.Annualroadtaxexemptionshavereceivedtheleastamountofattentionbyacademics.TheseincentiveshavebeenfoundtobeeffectiveinincreasingsalesofPEVsinlocationswherethisincentiveisapplied.

Reoccurringincentivesarenotavailableubiquitouslytoallconsumers.Thisisduetotheiravailabilitydifferingbetweenregions.Insomecases,theincentivesareonlyavailableinasmallnumberofurbanareas.Therefore,theycannotbeeffectiveinencouragingallconsumerstoadoptPEVs,onlyconsumerswhohaveaccesstothem.Thisissignificantlydifferenttohowfinancialpurchaseincentivesareapplied,wheretheclearmajorityofconsumersineachnationhaveaccesstothesameincentives.IntroducingreoccurringincentivesthatareavailabletoallconsumerswillbemoreeffectiveinpromotingPEVsales.ThisisthecaseinNorway.Norwaynotonlyhasthehighestnumberofincentivesbuttheincentivesareavailableubiquitouslyacrosstheentirecountry.ThishasledtoNorwayhavingthehighestPEVmarketshareofanynation.AnyincentivethatincreasestheconvenienceandreducesthecostofowningaPEVincomparisontoanICEVwillleadtomoreconsumersadoptingthem.TheyshouldalsobepairedwithpolicymeasuresthatapplydisincentivestoICEVs,suchasgastax(fuelduty).ThemosteffectivestrategywilltobeintroduceasmanyincentivesaspossiblesothatasmanydifferentconsumersareattractedtoPEVs.

3.1. PolicyRecommendationsPolicymakersshouldlooktointroduceasmanyreoccurringincentivesaspossibletopromotePEVsales.ThiswillresultinthelargerincreaseinPEVmarketsharecomparedtoastrategythatintroducesasmallnumberofreoccurringincentives.Incentivesshouldbeintroducednationwidesothatasmanyconsumersaspossiblehaveaccesstothem.Thisiscomparedtothecurrentsituationwhereincentivesaresometimesavailableonlyinisolatedareas.Thisliteraturereviewonlyconsiderstheeffectivenessofreoccurringincentivesthathavebeeninvestigatedbyacademics.Itmaybepossiblethatpolicymakersareconsideringtheintroductionofincentivesthathavenotbeeninvestigated.OverallanyreoccurringincentivethatincreasestheconvenienceandlowersthecostofowningaPEVincomparisontoanICEVwillbeeffectiveinpromotingtheiradoption.FortheincentivestobeeffectiveconsumersneedtobemadeawareofthemandshouldbeeducatedsothattheyunderstandthebenefitsofowningaPEV.

HOV,busandtransitlaneswillbemosteffectivewhenintroducedinregionswithhightrafficcongestion.Theintroductionoftheseisclearlyreliantuponthepresenceofmultilaneroadnetworksorthepresenceofbuslanes.TheuseofcarpoolorHOVlanesmaybepreferentialtoallowingPEVstodriveinbuslanesduetothepotentialfornegativeimpactsonbustraveltimes.ThoughitisunlikelyforthistooccurduringearlymarketintroductionsofPEVs.SomeregionshaveexistingnetworksofHOVorcarpoollanes,itispossiblethat

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rulesdictatingtheiraccesscouldbechangedtoallowPEVstoenter.OtherregionshavefewerHOVorcarpoollanesandthereforetheselaneswouldhavetobeintroducedalongwithallowingPEVstoaccessthem.ThiswouldbemorechallengingtoimplementbutwouldbebeneficialtoPEVs.Somecitiescurrentlyhavezoneswherecarsareunabletodrive,withareasbeingrestrictedtocertainvehicletypes(e.g.deliveryvehicles,taxisetc.)allowingPEVsaccesstotheseareaswillhaveasimilarimpactonPEVsalesasbuslaneaccesshashad.BuslaneaccesswillonlybeatemporarymeasurethatcanbeusedtosupporttheearlymarketforPEVs.AfterPEVshavegainedsignificantmarketsharesbuslaneswillbecomecongested.Therefore,thisincentiveshouldbeintroducedwithaphaseoutperiodinmind.ThisphaseoutcouldbeginwhenPEVshaveachievedacertainmarketshare.AgradualphaseoutcouldbepossiblewhichgraduallyincreasesthenumberofvehicleoccupantsneededinaPEVforthemtoaccessthelanes.ThishasbeenusedinNorwaywhereBEVswereoriginallyallowedtodriveinbuslaneswith1vehicleoccupant,thishasnowchangedto2vehicleoccupants.

Currentlymostparkingincentivesarelimitedtoheavilyurbanisedareas.Policymakersshouldcontinuetointroduceincentivesforparkinginurbanareas,butalsointroducetheminotherareas.Parkingincentivescanalsobeintroducedattransitstations,includingbusandrailstations.Theycanbeintroducedatanylocationswhereparkingiscostlyorspacesarescarce(e.g.shoppingmalls).IncentivescanincludefreeordiscountedparkingratesorpriorityspacesforPEVs.PriorityspacescanbespacesreservedonlyforPEVsandwouldusuallybepreferentiallylocated.Thiscouldbeclosetotheentranceofstore,theentranceofarailstation,onthebottomfloorofamulti-storycarpark,etc.OftenparkingspacesforPEVsalsohavechargingstationslocatednexttothemtoallowPEVdriverstorechargetheirvehicleswhilstparked.PolicymakersshouldconsidertheimpactofreducedrevenuebecauseofPEVsbeingabletoparkforfree.ItispossiblethatthistypeofincentivewillonlybeapplicableintheearlystageofPEVmarketintroductions.WhenPEVshaveamajority,marketsharethelossinrevenuemayhavenegativeimpacts.ItisalsopossibletointroduceparkingsurchargesforICEVsasamethodofencouragingconsumerstoadoptPEVs.ThisisbeingtrailedinLondonwheredieselICEVswillpay50%extratopark.ThiscouldallowfreeparkingforPEVstocontinueforlongerduetosurchargessupplementingthelostrevenuefromPEVs.ProvidingpriorityparkingspacesforPEVswillnotresultinlostrevenueandthereforemaybeaparkingincentiveswiththemostlongevity.

Tollfeewaiverscanbeintroducedonanyroadinfrastructurethathavetollfeesappliedtothem.Congestionchargezonesarelesswidespreadthantolls.Thoughtheycanbeeffectiveinreducingcongestionandencouragingconsumerstodrivelesspollutingvehicles.PolicymakersshouldconsiderintroducingcongestionchargezonesinmorelocationstoreducecongestionandincreasePEVsales.ThisissomethingthatiscurrentlyunderwayintheUK.TheLondoncongestionchargezone,whichhasoperatedsince2003,willbejoinedby5cleanairzonesacrosstheUK,thoughitiscurrentlynotclearwhetherfeeswillapplytopassengervehiclesoronlycommercialvehicles.TollfeewaiversforPEVscouldresultinlostrevenueforroadinfrastructureandthereforepolicymakersshouldconsiderthisimpactbeforeintroducingsuchschemes.CongestionchargearenewpolicymeasuresthereforeexemptingPEVsfromcongestionchargefeeswillnotresultinlostrevenueastheseareasrepresentanewsourceofrevenue.

ExemptionsorreductionsfromannualroadtaxesforPEVswillbeeffectiveinincreasingtheirmarketshares.ExemptingPEVsfromthesewillbemosteffectivewhenhighCO2

emittingICEVsareheavilytaxedmeaningthereisasignificanteconomicbenefitfor

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consumers.Aswithtollfeewaiversandfreeordiscountedparkingpolicymakersmustconsidertheimpactonrevenuebecauseofthis.AschemewherePEVsareexemptfromannualroadtaxuntiltheygainafootholdinthemarketmaybemosteffective.InthiswayPEVswouldpayalowrateaftertheyhavegainedafootholdinthemarketandthisratewouldincrementallyincreaseovertime.AnalternativesystemcouldinvolveintroducingaprogressivelyincreasingtaxforICEVswhichcanbeusedtosubsidisethelostrevenuefromPEVspayingnoroadtax.Thiswouldbeabonusmalusstylesystem.

Fueldutyorgastaxisappliedtovehiclefuelinmanyregions.ForittobeeffectiveinpushingconsumerstowardsPEVsitshouldbeprogressive,meaningthatovertimetheleveloftaxincreasesthusincreasingthecostoffuelforconsumers.ThistypeofincentivehasbeeneffectiveinpushingconsumerstowardsmoreefficiencyICEVsandPEVs.Policymakersshouldlooktointroducethistypeofpolicymeasure.Thistypeofmeasurehowevercanbepoliticallyunfavourableduetoconsumeroutcryregardingthepriceofvehiclefuel.

Foralltheseincentivespolicymakers,shoulddistinguishbetweenBEVs,PHEVswithhighelectricranges,andPHEVswithlowelectricranges(<30miles).BEVsandPHEVsarethemostbeneficialintermsofenergyconsumptionandemissionsandthereforeshouldreceivethemostincentives.PHEVswithlowelectricranges(<30miles)shouldreceivelowerincentivesthatalsoshouldbephasedoutsooner.ThisisbecausetheyachievelesselectricvehiclemilestravelledthanBEVsandlongrangePHEVs.Furthermore,driversofPHEVswithshorterrangesplug-intheirvehicleslessoftenthusexacerbatingtheissue.SomedriversofshortrangePHEVshavebeenfoundtoneverplugintheirvehicles(Taletal.,2014).

Policymakersneedtoconsiderimpactsonrevenuethatwouldresultfromparkingincentives,tollfeewaiversandannualroadtaxwaivers.IfalternativesourcesofrevenuecannotbefoundtheseincentiveswillneedtobephasedoutoncePEVshavegainedastablefootholdinthemarket.Itmaybepossibletoaccountforlossinrevenuebyenforcinghighertolls,parkingfeesorannualroadtaxonICEVs.

PolicymakersinsomenationsandregionsneedtoconsiderinteractionsbetweenPEVincentives,publictransportsystems,walking,andcycling.Thishasbeenpreviouslymentionedby(AjanovicandHaas,2016;BakkerandJacobTrip,2013).Somenations,forexampletheUnitedKingdom,manyotherEuropeannations,andChinahavehigherpublictransport,walking,andcyclingrates.IntheUnitedKingdom12%ofjourneysaretakenonpublictransport,inLondonthisfigureis38%.22%ofjourneysaredoneviawalkingintheUKand24%inLondon.Cyclingislessfrequent,butnotinsignificantwith2%ofJourneysintheUKandLondonbeingdoneviabicycle.ForcomparisonintheUnitedStatesonly5%ofjourneysareonpublictransit,5%bywalking,and1%bycycling.Inregionswithhighmodalsharesforpublictransportation,cycling,andwalkingpolicymakersneedtoconsiderinterventionsthatdonotencouragePEVuseoverpublictransport,walkingorcycling.PolicymakersshouldseektomakePEVusecheaperandmoreconvenientthanICEVusebutnotpublictransituse,walkingorcycling.Inthesecases,policymakersshouldseektointroduceincentivesthatmakeitmoreconvinceandcheapertoaccesstransitlocations.Thiscouldbeachievedbyhavingparkingandchargingincentivesatpublictransporthubs.

3.2. FutureResearchAllstudiesthatinvestigatetheimportanceofinfrastructureforPEVsconsiderPEVwithrangesofaround100miles.TherearenowseveralPEVsonthemarketwithrangesofmorethan200mileswithmorethan15modelsexpectedbefore2020.ConsumerswhopurchasetheseBEVsmayhavedifferentperceptionsrelatingtotheimportanceofinfrastructureduetothedifferingrangesoftheirvehicles.Theymayalsousetheirvehiclesdifferentlyand

25

havedifferentchargingbehaviours.FuturestudiesshouldinvestigatetheimportanceofrecharginginfrastructureforadoptersofPEVswitharound200milesofrange.Somereoccurringincentiveshavereceivedlessattentionintheliterature.Researchintotheimpactofcongestionchargezonesforexampleislimited.ThestudiesthatdidinvestigatethemfoundthemtobeinfluentialinshiftingvehicleusefromICEVstoPEVsorlesspollutingvehicles.Moreresearchisneededtoproperlyunderstandtheireffectiveness.MoreresearchisalsoneededtounderstandtheeffectivenessofannualroadtaxreductionsorexemptionsforPEVs.

ArecentproposalbytheDepartmentforAgricultureandRuralAffairsandtheDepartmentforTransport(DepartmentforEnvironmentandRuralAffairsandDepartmentforTransport,2016)intheUKincludessomeincentivesthathavenotbeenconsideredintheliteraturetodate.OneincentivewouldallowPEVstomoveofffromtrafficlightsbeforeICEVs.AnotherwouldallowPEVstodrivebothwaysdownstreetsthatarecurrently1-waystreets.TheseincentivesdoappearthattheywillincreasetheconvenienceofowingaPEVandthereforeshouldbeeffectivemeasures,thoughempiricalresearchshouldbeundertakentoensurethatthisisthecase.Someincentives,forexampletollexemptions,willnotbeabletolastindefinitelyduetoimpactsofrevenue.TheremovalofincentivestooearlyinthemarketintroductionofPEVswillhaveanegativeimpactonthemarket.PEVsshouldbeabletogainastablefootholdonthemarketpriortoincentiveremoval.Innovationtheorysuggeststhatnewproductmarketgrowthcanbeself-sustainingwhentheyachievearounda20%marketshare.WillthisbethecaseforPEVsandatthispointthemarketwillnolongerbereliantuponincentives?Thisquestionhassignificantimplicationsandneedstobegreaterunderstood.

4. AcknowledgementsTheauthorswouldliketothankClimateWorksFoundationforprovidingthefundingthatmadethisresearchpossible.

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5. ReferencesAasness,M.A.,Odeck,J.,2015.TheincreaseofelectricvehicleusageinNorwayincentives

andadverseeffects.Eur.Transp.Res.Rev.7.doi:10.1007/s12544-015-0182-4

Adepetu,A.,Keshav,S.,Arya,V.,2016.Anagent-basedelectricvehicleecosystemmodel:

SanFranciscocasestudy.Transp.Policy46,109–122.

doi:10.1016/j.tranpol.2015.11.012

Ajanovic,A.,Haas,R.,2016.Disseminationofelectricvehiclesinurbanareas:Majorfactors

forsuccess.Energy115,1451–1458.doi:10.1016/j.energy.2016.05.040

Bakker,S.,2010.Thecarindustryandtheblow-outofthehydrogenhype.EnergyPolicy38,

6540–6544.doi:10.1016/j.enpol.2010.07.019

Bakker,S.,JacobTrip,J.,2013.Policyoptionstosupporttheadoptionofelectricvehiclesin

theurbanenvironment.Transp.Res.PartDTransp.Environ.25,18–23.

doi:10.1016/j.trd.2013.07.005

Bjerkan,K.Y.,Nørbech,T.E.,Nordtømme,M.E.,2016.IncentivesforpromotingBattery

ElectricVehicle(BEV)adoptioninNorway.Transp.Res.PartDTransp.Environ.43,169–

180.doi:10.1016/j.trd.2015.12.002

Bonges,H.A.,Lusk,A.C.,2016.Addressingelectricvehicle(EV)salesandrangeanxiety

throughparkinglayout,policyandregulation.Transp.Res.PartAPolicyPract.83,63–

73.doi:10.1016/j.tra.2015.09.011

Caltrans,2017.HighOccupancyVehicleSystems[WWWDocument].URL

http://www.dot.ca.gov/trafficops/tm/hov.html

Caperello,N.,Tyreehageman,J.,Davies,J.,2015.Iamnotanenvironmentalwacko!Getting

fromearlyplug-invehicleownerstopotentiallaterbuyers.Transp.Res.Board2015

Annu.Meet.

Carley,S.,Krause,R.M.,Lane,B.W.,Graham,J.D.,2013.Intenttopurchaseaplug-inelectric

vehicle:AsurveyofearlyimpressionsinlargeUScites.Transp.Res.PartDTransp.

Environ.18,39–45.doi:10.1016/j.trd.2012.09.007

Chorus,C.G.,Koetse,M.J.,Hoen,A.,2013.Consumerpreferencesforalternativefuel

vehicles:Comparingautilitymaximizationandaregretminimizationmodel.Energy

Policy61,901–908.doi:10.1016/j.enpol.2013.06.064

Clinton,B.,Brown,A.,Davidson,C.,Steinberg,D.,2015.ImpactofDirectFinancialIncentives

intheEmergingBatteryElectricVehicleMarket:APreliminaryAnalysis.

27

DepartmentforEnvironmentandRuralAffairs,DepartmentforTransport,2016.DraftClean

AirZoneFramework.

Diamond,D.,2009.Theimpactofgovernmentincentivesforhybrid-electricvehicles:

EvidencefromUSstates.EnergyPolicy37,972–983.doi:10.1016/j.enpol.2008.09.094

Egbue,O.,Long,S.,2012.Barrierstowidespreadadoptionofelectricvehicles:Ananalysisof

consumerattitudesandperceptions.EnergyPolicy48,717–729.

doi:10.1016/j.enpol.2012.06.009

Figenbaum,E.,2016.PerspectivesonNorway’ssuperchargedelectricvehiclepolicy.

Environ.Innov.Soc.Transitions.doi:http://dx.doi.org/10.1016/j.eist.2016.11.002

Figenbaum,E.,Kolbenstvedt,M.,2016.LearningfromNorwegianBatteryElectricandPlug-

inHybridVehicleUsers.

Hackbarth,A.,Madlener,R.,2013.Consumerpreferencesforalternativefuelvehicles:A

discretechoiceanalysis.Transp.Res.PartDTransp.Environ.25,5–17.

doi:10.1016/j.trd.2013.07.002

Hardman,S.,2016.ConsumerAdoptionofFuelCellVehicles:LessonsfromHistorical

InnovationsandEarlyAdoptersofBatteryElectricVehicles.UniversityofBirmingham.

Hardman,S.,Chandan,A.,Tal,G.,Turrentine,T.,2017.TheEffectivenessofFinancial

PurchaseIncentivesforBatteryElectricVehicles-AReviewoftheEvidence(Article

UnderReview).Renew.Sustain.EnergyRev.

Hardman,S.,Tal,G.,2016.Exploringthedecisiontoadoptahigh-endbatteryelectric

vehicle:Theroleoffinancialandnon-financialmotivations.Transp.Res.Rec.J.Transp.

Res.Board16–1783.

Hoen,A.,Koetse,M.J.,2014.Achoiceexperimentonalternativefuelvehiclepreferencesof

privatecarownersintheNetherlands.Transp.Res.PartAPolicyPract.61,199–215.

doi:10.1016/j.tra.2014.01.008

Javid,R.J.,Nejat,A.,2017.Acomprehensivemodelofregionalelectricvehicleadoptionand

penetration.Transp.Policy54,30–42.doi:10.1016/j.tranpol.2016.11.003

Krause,R.M.,Carley,S.R.,Lane,B.W.,Graham,J.D.,2013.Perceptionandreality:Public

knowledgeofplug-inelectricvehiclesin21U.S.cities.EnergyPolicy63,433–440.

doi:10.1016/j.enpol.2013.09.018

Liao,F.,Molin,E.,vanWee,B.,2016.Consumerpreferencesforelectricvehicles:aliterature

review.Transp.Rev.1647,1–24.doi:10.1080/01441647.2016.1230794

28

Lieven,T.,2015.Policymeasurestopromoteelectricmobility-Aglobalperspective.Transp.

Res.PartAPolicyPract.82,78–93.doi:10.1016/j.tra.2015.09.008

Lutsey,N.,Slowik,P.,Jin,L.,2016.SustainingElectricVehicleMarketGrowthinU.S.Cities.

Mersky,A.C.,Sprei,F.,Samaras,C.,Qian,Z.(Sean),2016.Effectivenessofincentiveson

electricvehicleadoptioninNorway.Transp.Res.PartDTransp.Environ.46,56–68.

doi:10.1016/j.trd.2016.03.011

Nicholas,M.A.,Tal,G.,Turrentine,T.S.,2016.AdvancedPlug-inElectricVehicleTraveland

ChargingBehaviorInterimReportAdvancedPluginElectricVehicleTravelandCharging

BehaviorInterimReport.Inst.Transp.Stud.

Nicholas,M.a,Tal,G.,2013.ChargingforCharging :TheParadoxofFreeChargingandIts

DetrimentalEffectontheUseofElectricVehicles.

Ozaki,R.,Sevastyanova,K.,2011.Goinghybrid:Ananalysisofconsumerpurchase

motivations.EnergyPolicy39,2217–2227.doi:10.1016/j.enpol.2010.04.024

Percoco,M.,2014.Theeffectofroadpricingontrafficcomposition:Evidencefromanatural

experimentinMilan,Italy.Transp.Policy31,55–60.doi:10.1016/j.tranpol.2013.12.001

Plötz,P.,Gnann,T.,Sprei,F.,2016.Canpolicymeasuresfosterplug-inelectricvehicle

marketdiffusion ?EVS29.

Sangkapichai,M.,Saphores,J.-D.,2009.WhyareCaliforniansinterestedinhybridcars?J.

Environ.Plan.Manag.52,79–96.doi:10.1080/09640560802504670

Shewmake,S.,Jarvis,L.,2014.HybridcarsandHOVlanes.Transp.Res.PartAPolicyPract.

67,304–319.doi:10.1016/j.tra.2014.07.004

Tal,G.,Nicholas,M.A.,2014.ExploringtheImpactofHighOccupancyVehicle(HOV)Lane

AccessonPlug-inVehicleSalesandUsageinCalifornia.

Tal,G.,Nicholas,M.A.,Davies,J.,Woodjack,J.,2014.ChargingBehaviorImpactsofElectric

VehicleMilesTraveled-WhoIsNotPluggingin?J.Transp.Res.Board10.3141/24.

Tal,G.,Nicholas,M.A.,Turrentine,T.S.,Turrentine,T.,2017.FirstLookatthePlug-inVehicle

SecondaryMarket.Inst.Transp.Stud.

Tal,G.,Xing,Y.,2017.MODELINGTHECHOICEOFPLUG-INELECTRICVEHICLESIN

CALIFORNIA:ANESTEDLOGITAPPROACH,in:TransportationResearchBoard2017

AnnualMeeting.

Tietge,U.,Mock,P.,Lutsey,N.,Campertrini,A.,2016.ComparisonofLeadingElectric

VehiclePolicyandDeploymentinEurope.

29

Wang,Y.,Sperling,D.,Tal,G.,Fang,H.,2017.China’selectriccarsurge.EnergyPolicy102,

486–490.doi:10.1016/j.enpol.2016.12.034

Zhang,Y.,Qian,Z.(Sean),Sprei,F.,Li,B.,2016.Theimpactofcarspecifications,pricesand

incentivesforbatteryelectricvehiclesinNorway:Choicesofheterogeneous

consumers.Transp.Res.PartCEmerg.Technol.69,386–401.

doi:10.1016/j.trc.2016.06.014

Zheng,J.,Mehndiratta,S.,Guo,J.Y.,Liu,Z.,2012.Strategicpoliciesanddemonstration

programofelectricvehicleinChina.Transp.Policy19,17–25.

doi:10.1016/j.tranpol.2011.07.006