have we reached peak driving?: a 25-year decomposition of ... · class, the proportion of cars on...

Havewereachedpeakdriving?:A25-yeardecompositionofvehicletrendsinCanada

August10,2016

SarahShenstone-Harris

AmastersresearchprojectsubmittedtotheInstituteoftheEnvironmentinpartialrequirementsforthedegreeof

MastersofScienceinEnvironmentSustainability

Supervisor:NicholasRiversSecondReader:MatthewPaterson

InstituteoftheEnvironmentUniversityofOttawa

Shenstone-Harris 2016

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TableofContents

ABSTRACT 3

ACKNOWLEDGEMENTS 4

INTRODUCTION 5

LITERATUREREVIEW 8

EXTERNALCOSTSOFAUTOMOBILEDEPENDENCE 8TRENDSINCARUSE 9POSSIBLEEXPLANATIONSOFOBSERVEDTRENDS 10CANADIANLANDSCAPE 17RESEARCHQUESTIONS 18

METHODOLOGY&DATA 19DECOMPOSITIONANALYSIS 19REGRESSIONANALYSES 22DATASOURCES 29

RESULTS 31

DECOMPOSITIONOFVEHICLEUSEINCANADA&THEUNITEDSTATES 31OVERALLTRAVELDEMAND 31DECOMPOSITIONANALYSIS:UNITEDSTATES 34DECOMPOSITIONANALYSIS:CANADA 35EFFECTSOFGASOLINEPRICE,INCOME,ANDURBANIZATION 38

DISCUSSION 45

COMPARISONSBETWEENCANADAANDTHEUNITEDSTATES 45STRUCTURALFACTORSRESPONSIBLEFORCHANGINGVEHICLEUSE 46DRIVINGTRENDSAMONGAGEGROUPS 46ANAGINGPOPULATION 47URBANIZATION 48BEHAVIOURALFACTORSRESPONSIBLEFORCHANGINGVEHICLEUSE 49THEEFFECTOFGASPRICES 50THEEFFECTOFINCOME 51OTHEREXPLANATORYVARIABLES 53CAVEATSANDDATALIMITATIONS 53

CONCLUSION&IMPLICATIONS 56

REFERENCELIST 58

APPENDICES 63


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ABSTRACT

Theexternalcostsofvehicleuseareextensive,includingtrafficaccidents,urbancongestion,air

pollution, and greenhouse gas emissions. Around the turn of themillennia, after decades of steady

growth,percapitavehicleuseinmanywesterncountriesplateaued,orevendeclined.Astherehasbeen

very little research conducted on Canadian driving patterns, this study aims to determine whether

vehicleusehasbeenchanginginCanada,andhowitcomparestotheUnitedStates.Thisresearchseeks

toexplaintheinfluentialfactorsbehindvehicleuse,specificallytheeffectofanagingpopulation,rising

incomeandgasprices,urbanization,andotherelements.Anindexdecompositionanalysiswasapplied

toweightherelativeinfluenceofpopulationgrowth,demographicchanges,andindividualcaruse,in

both Canada and the United States, which was followed by a fixed-effect regression analysis to

determinetheinfluenceofgasprices,income,andurbanization.OurresultsfoundthatCanadahasnot

experiencedthesameremarkablechangeinvehicleusecomparedtootherwesterncountries,butonly

amodestpeakorplateau,withyoungadultsleadingthetrend.Gaspricesappeartoberesponsiblefor

someofthechange,althoughthiswasoffsetbythepositiveinfluenceofpopulationgrowth,andrising

incomes.Althoughthequalityofdataneedstobeimproved,understandingdrivingtrendsinCanadacan

helppolicymakersmanagevehicleuseanditsnumerousassociatedexternalities.


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ACKNOWLEDGEMENTS

Iwouldliketothankmysupervisor,Dr.NicholasRivers,forhisnever-endingguidanceand

unwaveringpatience,andforprovidingmewithsuchawonderfulopportunity.Iwouldalsoliketo

thankmysecondreader,Dr.MatthewPaterson,forhisthought-provokingcommentsandsuggestions.

Finally,IwouldliketothankmyfellowMESgraduatestudentsfortheirsupportandformaking

thisyeartrulyenjoyable.


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INTRODUCTION

Canada’s automobile dependency has had a notable effect on climate and air quality. Road

transportationaccountsfor23%ofallgreenhousegasesinCanada(EnvironmentandClimateChange

Canada2014), and is responsible fora substantialproportionof smogproduction (Environmentand

ClimateChangeCanada2016).Inaddition,vehicletravelisresponsibleforthousandsoftrafficfatalities

and serious injuriesper year inCanada (TransportCanada2015), and costsbillionsofdollars in lost

productivityasaresultofurbancongestion(TransportCanada2006).

Caruse,measuredaskilometrestravelledbypersonalvehicles,wassteadilyincreasingsincethe

emergenceoftheautomobileattheturnofthe20thcentury.Yetintheearly2000s,forthefirsttime,

carusestoppedgrowingintheUnitedStates(PuentesandTomer2008),Australia(StanleyandBarrett

2010), the United Kingdom (Metz 2010; Metz 2013; Le Vine et al. 2009), Germany, and France

(Kuhnimhofetal.2013),amongothercountries(Millard-BallandSchipper2011).Thetrendisparticularly

apparentamongyoungergenerations(Kuhnimhofetal.2012,Kuhnimhofetal.2013;GoodwinandVan

Dender2013).Varioustheorieshavebeenproposedtoexplainthechangeindrivingbehaviour,including

economicfactorssuchasthe2008recessionandincreasedgasprices,changingdemographics,shiftsin

youthculture,andurbanization,amongothers(Goodwin2012A).

As the baby boomers age, Canada’s senior population is growing (Employment and Social

DevelopmentCanada2016A),ademographicthathashistoricallydrivenless(USEIA2013;Dutzikand

Baxandall2013).Canadaisalsobecomingmoreurbanized,withOntario,BritishColumbiaandAlberta

housingthelargestproportionofurbandwellers(EmploymentandSocialDevelopmentCanada2016B),

whoalsotypicallydriveless(NewmanandKenworthy2006).However,todate,verylittleresearchhas


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beenconductedontrendsoftraveldemandanddrivingbehaviourinCanada,norhastherebeenmuch

researchattemptingtoquantifytherelativeimpactsofpotentialfactorsinfluencingvehicleuse.

This research aims todetermine if vehicle usehas been changingwithin the last 20 years in

Canada,consistentwithotherOECDcountries,andhowthesetrendscomparebetweenprovincesand

theUnitedStates.Thisresearchalsoseekstoexplaintheinfluentialfactorsbehindvehicleuseandto

quantify the relative contributions of an aging population, changing driving preferences, economic

factors,andotherelementsofvehicleuseinCanadaandtheUnitedStates.

Time seriesdatawere collected fromNaturalResourcesCanada, TransportCanada, Statistics

Canada,andprovincialtransportationministriesandautoinsuranceagencies,andaggregatetrendsin

vehiclekilometresweredecomposedusinganindexdecompositionanalysis.Alogarithmicdivisiamean

indexwasappliedtoquantifytherelativecontributionsoffactorsaffectingcaruse,includingpopulation

growth,changingagestructureofthepopulation, licensingrates,andvehiclekilometrestravelledby

differentagegroups.TrendsweredecomposedatanationallevelandcomparedwithAmericanvehicle

use.Next,amultipleregressionanalysiswasundertakentoestimatetherelationshipbetweenCanadian

vehicletravelandseveralothervariables,includinggasprice,income,andthepopulationshareinurban

centres.

WefoundthatpercapitavehiclekilometrestravelledinCanadahavenotexperiencedthesame

remarkablechangecomparedtootherwesterncountries.Forinstance,Americanpercapitavehicleuse

wasgrowingsteadilyuntiltheearly2000s,afterwhichitbegantoleveloffanddecrease.Comparatively,

Canadaexperiencedonlyamodestpeakorplateau,althoughsomeprovincesexhibitedadeclinewhile

othersexperiencedanincrease.InboththeU.S.andCanada,thedeclineorplateauinvehicleusecan

beattributedtochangesinindividualbehaviour,wherepeoplearedrivingless,especiallyyoungadults.


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Thisdeclinewasoffsetbypopulationgrowthandgrowingincomes,bothofwhichareincreasingacross

NorthAmerica.Alternatively,gaspricesappeartoberesponsibleforpushingvehicleusedownwardsin

Canada.TheeffectofanagingpopulationishavinglittletonoeffectondrivingtrendsinNorthAmerica.

Finally,theregressionanalysissuggeststhattheeffectofincreasingurbanizationinCanadaishavingno

effectondrivingtrends,althoughthismaybetheresultoflowvariabilityand/orinaccuratedata,rather

thanactualsettlementpatterns.

Althoughitisimpossibletopredictfuturetrendsintransportation,understandingthepossible

factors influencing driving behaviour in Canada will help provide more accurate projections and

considerations for transportation and land-use planning, fuel consumption projections, and climate

mitigation.Understandingwhydrivingpreferenceshavechangedoverthelast25yearscanhelppolicy

makersmanagevehicleuseandthenumerousassociatedexternalities.


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LITERATUREREVIEWExternalCostsofAutomobileDependence

Sincetheemergenceoftheautomobileattheturnofthe20thcentury,withcheapfuelpricesand

lower manufacturing costs, North Americans became increasingly dependent on the automobile,

allowingindividualtotravelfasterandfarther(Headicar2013).However,vehicletravelisresponsible

foranumberofcoststosociety.Themostimportantsocialcostcomesfromurbantrafficcongestion

(ParryandSmall2005),whichwasresponsiblefor$2.3billionto$3.7billionoflostproductivityin2002

(TransportCanada2006).Vehicletravelisalsoresponsibleforthousandsoftrafficfatalitiesandinjuries;

in 2013 alone, 1,923 Canadians died in motor vehicle accidents and 10,315 were seriously injured

(TransportCanada2015).Finally,cardependencyhasproducedmajorenvironmentalimpacts,namely

worsenedairqualityandgreenhousegasemissions.Vehicleemissionsareresponsibleforoverhalfof

allsmogproduction,includingvolatileorganiccompounds,nitrogenoxides,andparticulatematter(U.S.

EPA2015).EachyearinCanada,smogcontributestothousandsofprematuredeaths,increasedhospital

anddoctorvisits,andlostproductivityatschoolandwork(EnvironmentCanada2014).Vehicleemissions

fromfuelcombustionarealsoasignificantdriverofglobalclimatechange.In2014,23%ofgreenhouse

gasesinCanadacamefromthetransportationsector(EnvironmentandClimateChangeCanada2014),

almosthalfofwhichwerefromprivatevehiclesalone(EnvironmentCanada2011).TheInternational

EnergyAgency(2015)projectsthatnearlyhalfoftheincreaseinenergy-relatedemissionsinthenext15

yearswillcomefromthetransportsector.Together,theseexternalitiescostbillionsofdollarstothe

Canadianeconomy.For instance, Jakobetal. (2006)estimatedthat theexternalitiesassociatedwith

publicandprivatetransportationcosts2.23%oftheGDPofAuckland,NewZealandeachyear.InCanada,

the population and landmass, and thus subsequent vehicle use, is much greater. Consequently,


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international, national and local governments all recognize the need to reduce the externalities of

vehicleuse(IPCC2014;EnvironmentCanada2013a).

TrendsinCarUse

InmostdevelopedcountriessinceWorldWarII,withsuburbanisationandaburgeoningmiddle

class,theproportionofcarsontheroadrelativetopopulationhadbeenincreasing(Millard-Balland

Schipper2011).Thistrendisoftenviewedasafunctionofincome,wherepeopleshifttofaster,more

reliableformsoftransportation,albeitmoreenergy-intensive,astheirincomeandnationalGDPincrease

(Dargayetal.2007;IPCC2014).ThiswasthetrendinalmostallOECDcountries(Dargayetal.2007),and

by2007,90%oftripsintheUnitedStatesweretakeninautomobiles(IPCC2007).Yetthereisgrowing

evidencethatthetrendsofcontinuouslygrowingcaruse,anditsstrongcouplingtoGDP,arechanging.

Declinesincaruse,asmeasuredbyvehiclekilometrestravelled,werefirstdocumentedbythe

BrookingsInstitutein2008(PuentesandTomer2008),andwithinthelastsevenyears,thisemerging

trendofplateauingordecliningcaruse,sometimescalled“peakcar,”hasbecomewelldocumented

(Newman and Kenworthy 2011; Goodwin 2012A; Goodwin and Van Dender 2013). The Brookings

InstitutefoundthatintheUnitedStates,peoplehavebeendrivinglesseachyearsince2007,bothin

urbanandruralareas(PuentesandTomer2008).Notonlyhasvehiclekilometresdecreased,butdriver’s

licensesissued,numberoftripstaken,andnewvehiclessoldhasalsodeclined(Puentes2012),while

publictransituseisontheriseandisatitshighestsince1957(PuentesandTomer2008).From1995to

2005,caruseinLosAngelesandSanFranciscodeclinedby2%and4.8%,respectively,andAtlantaand

Houstonexperiencedlargerdeclinesof10.1%and15.2%,respectively(NewmanandKenworthy2011).

Thismarked and unprecedented change in driving habits is not limited to theUnited States

however; it has also been documented in Australia, the United Kingdom, and continental Europe


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(Millard-Ball andSchipper2011;Metz2010;NewmanandKenworthy2011;Kuhnimhofet al. 2013).

AmongeightOECDcountries,vehicleownership,vehiclesuse,andoveralltraveldemandwassteadily

increasing from the 1970s until the early 2000s (Millard-Ball and Schipper 2011). Around 2004, car

ownershipstartedtorisemuchmoreslowly,whiletraveldemandandvehicleusedeclinedrelativeto

GDP(Millard-BallandSchipper2011).InthefivemostpopulouscitiesofAustralia,Sydney,Melbourne,

Brisbane,Adelaide,andPerth,percapitacarusepeakedin2004,andhassincebeendecreasing(Stanley

andBarrett2010).IntheUnitedKingdom,overallcarusehascontinuedtoincreasewithpopulation,yet

percapitacarusehasstabilized(Metz2010).Metz(2010)foundthatfrom1972to2009,household

travelexpenditure,purposeoftrips,frequency,andtraveltimeallremainedstable,whiletheaverage

distancetravelledwassteadilyincreasingfor30yearsuntilitplateauedaround2002.

Although it is not possible to tell how this trendwill unfold in the future, Goodwin (2012B)

proposedthreepossibleprojectionsoftraveldemand.Carusecouldeitherreboundandgrowoncethe

economyhasimproved,continuedecreasing,orcouldstabilizeandremainatitscurrentlevel(Goodwin

2012B).Althoughitisnotpossibletopredictthefuture,understandingthevariousfactorsinfluencing

vehicledemandwillhelpmakedecisionsinthefutureintermsoftransportationplanningandclimate

mitigation.

PossibleExplanationsofObservedTrends

EconomicfactorssuchasGDPhavebeenproposedtoexplainpeakdrivingtrends,althoughthere

issubstantialdebatesurroundingthisexplanation(Goodwin2012A;GoodwinandVanDender2013).

Thehistorical linkbetweenincomeandcarusehasbeenwellestablished(GoodwinandVanDender

2013),howeverintheU.K.andU.S.,theybegantodecoupleinthelastdecade(U.S.EnergyInformation

Administration(EIA)2014;Metz2012;Metz2013;LeVineetal.2009).For instance,untilthe1990s,


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averagedistancetravelledincreasedintandemwithrealhouseholdincomesintheU.K.untilthelate

1990s,afterwhich incomescontinued to risewhilekilometres travelledstabilizedoreven fell (Metz

2012).Therelationshipbetweenincomeandvehicleuseislessclearathigherincomes(Goodwinand

Van Dender 2013). A study in England andWales found that in recent years, car use has declined

significantly among higher earning men, while lower income men were still increasing vehicle use

consistent with historical trends (Goodwin 2012A). Likewise, the proportion of cars on the road in

developingcountriesisstillincreasing(Dargayetal.2007).IntermsofoverallGDP,the2008recession

hasalsobeenproposedaspossibleexplanationstothe“peakcar”phenomenon,howeverAustralia,the

U.K.,andtheU.S.allexhibitedadecrease indrivingbehaviourduringaperiodof relativeprosperity

beforethe2008globalrecession(NewmanandKenworthy2011;Metz2010;Puentes2012;LeVineet

al.2009).

Theriseingasolineandfuelpricesglobally,especiallyinEurope,hasalsobeensuggestedasan

explanationfordecliningvehiclekilometrestravelled(Puentes2012;EIA2013).Recentresearch

estimatestheelasticitiesofvehicledistancetravelledwithrespecttogaspricestobearound-0.1in

theUnitedStates(Gillinghametal.2015),thoughtheyappeartobeslightlyhigherfornewvehicles

alone,atroughly-0.22(Gillingham2014).ElasticitiesinCanadaaresimilar;Barlaetal.(2009)

estimatedgaspriceelasticityofdrivingdemandtobeapproximately-0.2inthelongrun.Suchlow

elasticitiesofdemandshouldnothaveaverylargeimpactongasolineconsumptionandcaruse

(Kayser2008;Barlaetal.2009).Alternatively,Hughesetal.(2008)foundthatpriceelasticitiesofgas

consumptionhavefallensince1975andwereestimatedtobeat-0.034and-0.077during2001and

2006.Usingelasticitiesofgasconsumptionof-0.034and-0.077,Millard-BallandSchipper(2011)

estimatedthatintheU.S.withthe15%increaseinfuelpricesin2008,thereshouldhavebeena1%


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declineingasolineconsumption,basedonestimatedpriceelasticityoffuel.However,therewasa4.3%

reductioninfuelconsumptionforprivatevehicles,suggestingthatfuelpricescannotexplainrecent

changesindrivingbehaviourfully(Millard-BallandSchipper2011).Otherresearchersalsonotethat

thelevellingoutofvehicleuseoccurredbeforetheescalationofoilpricesin2002(PuentesandTomer

2008;LeVineetal.2009).Nonetheless,income,fuelprices,thecostsofdriving,andothereconomic

factorsallcontributetovehicleuse,althoughtowhatextentisdifficulttoknow(Puentes2012;U.S.

EIA2013).

As the baby-boomers age, most developed countries, including Canada, are experiencing a

rapidlygrowingseniorpopulation(EmploymentandSocialDevelopmentCanada2016A).Theamountof

driving is typically dependent on one’s life stage; thosewho are participating in theworkforce and

commutetendtodrivemore (USEIA2013;DutzikandBaxandall2013).DutzikandBaxandall (2013)

arguethatthelargegrowthinvehicleusein1980sand1990swastheresultofbabyboomerspassing

through their primeearning and child-rearing years,where theywouldbe frequently commuting to

work,drivingtheirchildren,andtypicallylivinginmorecar-dependentneighbourhoods.However,baby

boomersarerapidlyexitingthelabourforceandretiring(EmploymentandSocialDevelopmentCanada

2016A),alifestagethathashistoricallydrivenless(DutzikandBaxandall2013).Aswell,aspartofthe

“empty-nestersyndrome”,manyolderadultsareleavingthesuburbsandresettlingincities,whereless

drivingisrequired(NewmanandKenworthy2011).Althoughpeoplearelivinglonger,seniorsmayalso

self-limit driving by shortening trips or travelling less as a consequence of physical and mental

impairments(BraitmanandMcCartt2008),althoughthereisdebateastowhetherdisabilityisincreasing

ordecreasingaslifeexpectancieslengthen(Metz2012).NewmanandKenworthy(2011),Millard-Ball

andSchipper(2011),Metz(2012)andtheUSEIA(2013)suggestthatsincetheshareofseniorsisrapidly


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growing,andasoldpeopleshoulddriveless,agingpopulationscouldbecontributingtothedeclinein

vehicleuse.

However,Kuhnimhofetal.(2012)foundtheoppositeinGermany,whereolderpeoplearedriving

morethaneverbefore,butthedramaticdeclineofcarusein18-29yearoldsisovershadowingother

agegroupsandshapingthenationaltrend.Kuhnimhofetal. (2013)quantifiedtherelative impactof

bothchangingagestructureandvehicletraveldemandinFrance,Germany,GreatBritainandtheU.S.

Theyfoundthatalthoughagingdidplayanimportantroleinoverallnationaltrends,particularlyafter

theturnofthecentury,changesintraveldemandandshiftstodifferentmodesplayedamuchmore

significantrole(Kuhnimhofetal.(2013).Infact,youngadultsmadethelargestnegativecontributionto

recentchangesinpercapitavehicleuse(Kuhnimhofetal.2013).

In previous generations, a driver’s license was an important rite of passage into adulthood,

especially for males, but today fewer young people are learning how to drive (Goodwin 2012A;

Kuhnimhofetal.2012).Infact,thelicensingrateforyoungpeopleintheU.S.andGreatBritainhasbeen

insteadydeclinesincetheearly1990s(U.S.EIA2014;LeVineetal.2009).InGermany,18to29year

olds used to be the most car-oriented group, yet today they drive less than all other age groups

(Kuhnimhofetal.2012). Infact,Kuhnimhofetal. (2012)foundthatyoungmenexhibitedthe largest

decreaseincaruse,whileyoungwomen’sbehaviourremainedrelativelystable,andLeVineetal.(2009)

foundthatgenderdifferencesindrivingbehaviourinGreatBritainweredisappearing.Kuhnimhofetal.

(2012)foundthatinthelastdecade,youngadults’ownershipof,oraccessto,carsdeclinedsignificantly

foryoungpeoplewhohavelefttheirparentshousehold,butcaruseremainedunchangedfortheyoung

coupleswithchildren.Youngadults,eventhosewithaccesstoacar,arenowshiftingtomultiplemodes

of travel, particularly public transit (Kuhnimhof et al. 2012; Davis et al. 2012). Public transportation


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among young adults nearly doubled from 1997 to 2006 in Germany (Kunhimhof et al. 2012), and

ridershipincreased32.3%intheUnitedStatesfrom1995to2011,doublethatofthepopulationgrowth

rate(Puentes2012).However,multimodaltravelbehaviourdependsontheavailabilityofreliableand

affordablealternativetransportation(Puentes2012),whichislackinginmanypartsofCanadaandthe

UnitedStates.Thedeclineincarusebyyoungadultsmaybelinkedtoeconomicfactors,suchaslimited

employmentanddebt (Kunhimhofetal.2012;Puentes2012). InaUKsurveyofnon-licensedadults,

youngpeopleweremorelikelytomentioncost-relatedfactors,whileolderpeopleweremorelikelyto

citereasonssuchasdisinterestandphysical limitations fornot learningtodrive (UKDepartment for

Transport2015).However,intheU.S.,thedeclineincarusebeganbeforeyouthunemploymentspiked

in2009(Davisetal.2012).Kuhnimhofetal.(2012)suggestthatthecostofdriving,includingfuelprices

andthecostofcarownershipincreasedsubstantiallyinthe1990sinEurope,whilereal-timeincomes

grewmoreslowly.Thechangeinyouthculturearoundcarsmayalsobeduetosocioeconomicshiftsin

thepopulation;moreyoungadultsareattendinguniversityandparticipatinglessintheworkforce,while

startingfamilieslaterthantheircounterpartsinpreviousgenerations(Kuhnimhofetal.2012).

Manyresearchersagreethatthechangeinbehaviourcanbepartlyexplainedbyre-urbanisation

of largecities (Headicar2013;NewmanandKenworthy2011;Metz2013;GoodwinandVanDender

2013).Thisisparticularlyapparentforcitieswithavailablealternativemodes,suchasextensivepublic

transportationorsafewalkingroutes(GoodwinandVanDender2013).Headicar(2013)foundthatthe

differenceinannualkilometrestravelledbetweenthemostandleasturbanizedareasinEnglandhas

been widening considerably since the 1980s, with the least urbanized areas now driving triple the

distanceasaresultofland-useplanningandsettlementcharacteristics.Forthelasttwodecades,many

AmericanandAustraliancitieswereseeinganurbanrenaissance(NewmanandKenworthy2011),and


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manycitiesintheU.K.havebecomemuchdenserasthegovernmentadoptsmorepoliciestodiscourage

greenfielddevelopmentandsprawl(Headicar2013;GoodwinandVanDender2013).Headicar(2013)

suggeststhatthestagnationofpercapitacaruseinEnglandinthelate1990sandearly2000scoincided

withadramaticincreaseintheshareoftotalpopulationlivinginurbanizedareas.Metz(2013)found

thatevenasLondon’surbanpopulation,density,andincomegrows,percapitacaruseisdecreasing.In

GreatBritain,thegreatestdeclineindrivingwasinLondonandothermajorcities,whiletherestofthe

countryremainedrelativelylevelintheirvehicleuse(LeVineetal.2009).However,percapitavehicle

useinruralareasintheUnitedStateshasalsobeendecreasingsince2006(PuentesandTomer2008).

Newman and Kenworthy (2011) and Puentes (2012) propose that cities may be hitting a

“MarchettiWall,”wherebypeopledonotwanttotravelmorethan1.1hoursaday.Withincreasingly

largecities,vehiclecommutetimescouldeasilyexceed1.1hours,subsequentlyencouragingindividuals

to migrate to denser areas with shorter, but perhaps slower, commute times. For example, the

commutingtripspeedsarelowerindenser,lesscar-orientedcities,comparedtolowerdensitycities,

while travel time itself is relatively stable (KenworthyandLaube1999).This is consistentwithother

research(Millard-BallandSchipper2011;Metz2010),whichfoundthatalthoughvehicleuseisdeclining,

thetraveltimeamongallmodeshasremainedataround1.1hoursaday.

Alternatively,Metz(2013)proposedthattraveldemandhasbeensaturated,asindividualshave

adiminishingmarginalutilityfortheadditionalaccessandchoicetheautomobilecanprovide.Asmore

optionsandchoiceincreasewithgreaterurbanandsuburbandevelopment,traveltofartherdistances

viacarisnolongernecessary,saturatingthedemand(Metz2013).Goodwin(2012B)foundthatonlya

quarterofthedeclineincartripsintheUKfrom1999to2009couldbeexplainedbymodalsubstitutions,

while the restwas the result of shortened journeys. In addition,many cities arenowattempting to


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promotemorepedestrianizeddowntowns,withtrafficcalmingandlessparking,andencouragingmore

multimodalbehaviour,whichmaybeaffectingpeople’sdrivingbehaviour(Kuhnimhofetal.2012).

It has alsobeen suggested that technology is replacing theneed for vehicle travel (Goodwin

2012A;Metz2013;Puentes2012).Forinstance,peoplecouldbetravellinglessinexchangeformore

tele-commutingande-commerce.However, todate there is littleconclusiveevidenceontheroleof

technologyinfluencingtravelbehaviour(Kuhnhimhofetal.2012;GoodwinandVanDender2013)

Changes in driving patterns are not likely due to one single factor, but the convergence of

multiplefactors(GoodwinandVanDender2013;NewmanandKenworthy2011;Puentes2012).The

heterogeneityindrivingpatternswithindevelopedcountriesislikelytheresultofurbanandtransport

policies,personalpreference,andfinancialconstraints(GoodwinandVanDender2013).Goodwinand

VanDender(2013)suggestthatchangesincarusewasfirstfueledbyeconomicforces,butwasthen

propagatedbyother factorsuchaspublic transit investments,policies torestrict trafficandparking,

gradual immigration to denser urban areas, advancements in information technology, and changing

attitudestowardsthecar.Forinstance,averagerealincomeshavereboundedsincethe2000s,however

carownershipandusehasnotfollowedsuit,perhapsduetochanginghabitsandattitudes(Goodwin

and Van Dender 2013). Regardless, little research has been conducted on how these economic,

demographic,andsocialfactorscompareintermsofrelativeinfluenceondrivingbehaviour.

Althoughitisimpossibletopredictfuturetrendsintransportation,understandingthepossible

driversbehindaggregatetrendscanhelpproducemoreaccurateforecastsandconsiderationsforthe

future(Goodwin2012;GoodwinandVanDender2013).Thiscouldincludeinfrastructureinvestment,

land-useplanning,emissionsaccounting,andenergyandfuelconsumptionmodelling.


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CanadianLandscape

Canadahasthehighestpopulationgrowthrate(0.9%)amongallG7countries,withimmigration

accountingfortwothirdsofthegrowth(StatisticsCanada2015.)Ontario,Quebec,BritishColumbiaand

Albertamakeup86.3%ofCanada’spopulation(StatisticsCanada2015).Seniorsmakeupthefastest-

growingagegroupinCanada,duetothelowerfertilityrateofyoungadults,longerlifeexpectancies,

andtheagingbabyboomers(EmploymentandSocialDevelopmentCanada2016A).In2011,therewere

5millionseniorsinCanada,andby2051,oneinfourCanadiansisexpectedtobeover65(Employment

and Social Development Canada 2016A). Currently, seniors in theMaritimes, Quebec, Ontario, and

BritishColumbiaoutnumberchildrenaged0to14,whiletheoppositeistrueinthePrairieProvinces

(StatisticsCanada2015).Asdiscussedpreviously,thisrapidlygrowingshareofseniorsarenottypically

partoftheworkforceandthusdonotcommute,tendingtodrivelessthanindividualsinotherlifestages

(USEIA2013;DutzikandBaxandall2013).

TheproportionofCanadians living inurban centres, nowat81%,hasbeenon the rise since

Confederation, with one third of all Canadians now living in Toronto, Vancouver and Montreal

(EmploymentandSocialDevelopmentCanada2016B).In2011,Ontario,BritishColumbiaandAlberta

had a larger proportion of their population living in urban areas than the national average, while

ManitobaandPrinceEdwardIslandhadsignificantlymoreruraldwellersthantheaverage(Employment

andSocialDevelopmentCanada2016B).Finally, the incomegapbetweengenerations iswidening in

Canada,withgreater inequalitybetweenyoungandolderCanadiansnow,comparedto30yearsago

(Gilletal.2014).AlthoughthesefactorsallinfluencedrivingbehaviourinCanada,todatetherehasbeen

almostnoresearchonpeakdrivingtrendsinCanada.


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ResearchQuestions

1. Inthelast25years,didvehiclekilometrestravelledinCanadareachapeakorplateauintheearly

2000s?

2. HowdopatternsinvehicleusecomparebetweenprovincesandbetweenCanadaandtheUnited

States?

3. Ifthereisachangeincaruse,whataretheprobablecauses?Forinstance,isittheresultofan

agingpopulation,lessoverallactivitybyyoungadults,lowerlicensingrates,economicinfluences,

orotherfactors?

Hypotheses

1. IntheUnitedKingdom,theUnitedStates,Australia,Germany,andotherOECDcountries,vehicle

kilometrestravelledplateauedorbegantodeclineintheearly2000s.GivenCanada’scultural,

social,andeconomicsimilarities,weexpecttoseeatrendinCanadaconsistentwiththeUnited

StatesandAustralia,withdecreasingvehiclekilometrestravelledbeginningaround2004.

2. We expect that all provinces will have declining or plateauing per capita car use, although

provinceswithgreaterurbanpopulationandpublictransit,suchasOntarioorBritishColumbia,

willhaveamoreprominentchangecomparedtomoreruralprovinceswithlessalternativetransit

optionssuchManitoba.CanadaandtheUnitedStatesshouldhavesimilarpatterns,andrelatively

equalcontributionsofinfluencingfactors.

3. Althoughanagingpopulation, lessoverallactivitybyyoungadults, lower licensing rates,and

economicinfluenceslikelyallplayaroleininfluencingdrivinghabits,decliningactivitybyyoung

adultsprobablyhasthegreatestimpactondrivingbehaviour,throughmodalshiftsandlower

licensingrates.


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METHODOLOGY&DATADecompositionAnalysis

Canadianvehiclekilometrestravelled(VKT)wereexaminedfrom1990to2013toassessifcar

usehasbeenfollowingsimilarpatternstootherOECDcountries,wherebypercapitadrivingincreased

steadilyuntilthelate1990sorearly2000s,followedbyaplateauordecline.Canadianvehicleusewas

compared to American patterns, and within Canada, comparisons were conducted between all ten

provinces.VKTwerecombinedforBritishColumbiaandtheterritories.

An index decomposition analysis (IDA)was used to decompose trends in driving, in order to

determinewhathasbeenresponsibleforchanges inVKT. Indexdecompositionanalysis is frequently

usedtodeconstructenergyconsumptionorgreenhousegas(GHG)emissionswithinanindustry,asit

allowsonetodeterminewhatisresponsibleforchangesinenergyuseoremissions(Ang2004).Asan

illustrativeexample,imaginethatGHGsfromenergyproductionaredecliningintheprovinceofAlberta.

Thereareafewpossibleexplanations;itcouldbeduetolessoverallenergybeingdemanded,itcould

betheresultofashiftawayfromcoal towards lowercarbonenergysources,or itcouldbebecause

power plants are becoming cleaner and more efficient. Alternatively, it could be a combination;

economicdevelopmentcouldbegrowingandsubsequentlydemandingmoreenergy,buttheenergy

sectoritselfcouldbereleasingfewerGHGsasAlbertamovesawayfromcoal.Thisrelationshipcanbe

quantifiedusingthefollowingequation;

𝐺𝐻𝐺 = 𝐴𝐴%𝐴

%

𝐸%𝐴%

whereA is thetotalactivity levelofallproductionsources,Ai is theactivity levelofeachproduction

sourcei,andEiistheemissionsforeachproductionsourcei.Thiscanbesimplifiedto;

(1)


20

𝐺𝐻𝐺 = A 𝑆%%

𝐼%

whereAistothetotalactivityofenergyproduction,Siisthestructureofproductionsources(howmuch

energyisfromcoal,nuclear,etc.),andIiistheemissionintensityofproductionsourcei.AnIDAallows

onetoquantifyeachofthesefactorsanddeterminehowtheyarecontributingtotheoveralltrendin

GHGs,oranyothervariableofinterest.

IDAshavenotoftenbeenappliedtopersonalvehicletravel,althoughsomeexamplesdoexist.

Millard-BallandSchipper(2011)successfullyappliedanIDAtoanalyzetheenergyintensityofmotorised

travel, includingvehicleandairtravel,foreighthigh-incomecountriesoverthelastfortyyears.They

foundthatbefore2004, increasedenergyuse inthetransportsectorwasmostlydueto increases in

personal travel demand, although this was counterbalanced slightly by improved energy efficiency

(Millard-BallandSchipper2011).Mostnotably,theauthorsfoundthattotalmotorisedpassengertravel

peakedin2004;theysuggestedthatifenergyefficiencycontinuestoimprove,andindividualsshiftback

towardstrainsandbusessomewhat,emissionsfrompersonaltravelcouldbelowerthantheywerein

2011by2020or2030(Millard-BallandSchipper2011).Usingamoresimilarmethodtoours,Kuhnimhof

etal.(2013)usedanIDAtoassesstherelativeimpactsofdemographicchanges,overalltraveldemand,

andpersonalvehicleuseintheUnitedStates,France,Germany,andGreatBritain.Theydeterminedthat

inFranceandtheU.S.,recentchangesinVKTwereduetodeclinesinalltravelmodes,whileinGermany

andGreatBritain,modalshiftsawayfromcarsalsoplayedasignificantrole(Kuhnimhofetal.2013).

In this case, we applied an IDA to assess yearly changes in VKT and its component parts:

populationgrowth,changingagestructureofthepopulation,licensingrates,andtotaldistancedriven

perdriver.Thedatawasnotavailabletoconductaprovince-by-provincecomparisonofdisaggregate

trends invehicleuse,soCanadianpatternswereinsteadcomparedtoAmericanvehicletravel.Using

(2)


21

mathematicalequationsoutlinedinAng(2005),theIDAallowedustoweightherelativecontributionof

eachfactoranddeterminewhatisresponsibleforoveralltrendsinVKT.Thegoverningfunctionforthe

IDAisasfollows,

𝑉𝐾𝑇 = 𝑃𝑃/𝑃

/

𝐷𝐿/𝑃/

𝑉𝐾𝑇/𝐷𝐿/

whereVKTisvehiclekilometrestravelled,Pispopulation,aisagegroup,andDListhenumberoflicensed

drivers.Morespecifically,Ptowardstheleftrepresentspopulationgrowth,232measuresagestructureof

the population over time, 45323

represents licensing rates for each age group over time, and finally,

changesintotaldistancedrivenperdriverismeasuredas6783453

.Usingthemathematicalformulations

describedbyAng (2005), theaggregate trendand relativecontributionofeachof these factorswas

quantifiedandcompared.Driverswerecategorizedintofouragegroups:under24,25to44,45to64,

andover65.ForCanadiantrends,theIDAwascompletedforeveryyearbetween2000and2009,except

for2001duetodatalimitations,asdiscussedbelow.Aperiod-wiseIDAwascompletedfortheUnited

States,from1995to2001,andfrom2001to2009.TheavailabledatafromtheUnitedStatesdidnot

supportayearlydecomposition.

An IDA has certain implicit assumptions; it assumes that if there is a change in one of the

componentfactors,theaggregatevariablewillchangeproportionally.Thisisalimitationtothemethod,

as the component and aggregate variables are not necessarily proportionally related, and the

relationship may be much more complex. Nonetheless, it is still a useful and powerful method to

understandvehicleuse.

Multiplemethodsexisttoconductdecompositionanalyses,suchasLaspeyresmethodorFisher

Ideal, however someare better thanothers (Ang 2004; IEA 2013). A logarithmic divisiamean index

(3)


22

(LDMI)wasusedforourIDA,foranumberofreasons.Mostimportantly,theLDMIapproachproduces

perfectdecomposition,meaningthattherearenounexplainedresidualtermsintheresults(Ang2004).

LDMIisalsoadaptable,itcanbeappliedtotime-seriesdatawithouthavingtochangethemathematical

formulafordecomposition(Ang2004).Aswell,thedecompositionformularemainsthesameregardless

of how many factors are being quantified (Ang 2004). The LMDI method can also be conducted

multiplicativelyoradditively;theformerdecomposesthe“ratio”ofchangeoftheaggregatevariable,

while the latter decomposes the “difference” of change (Ang 2004). This provides LDMI with a

methodologicaladvantage,asonecanuseitregardlessoftheirpreferredtypeofassessment(Ang2004).

Finally,theLMDIapproachisstraightforwardtoconduct,andresultscanbeeasilyinterpreted,inpart

becausetherearenounexplainedresidualterms(Ang2004).Forthesereasons,theLDMIapproachis

themostpreferred(Ang2004;IEA2013).

RegressionAnalyses

A formal IDA quantifies the relative contribution of various factors to explain changes in an

aggregatetrend,inthiscasechangesinVKTovertime.Unfortunately,IDAsarequitedataintensiveand

requireallvariablestofitintoamathematicallysoundequation.Asaresult,theIDAcouldnotinclude

othervariables,suchasincome,whichmayalsobeaffectingVKT.Forinstance,theIDAmaysuggestthat

thevariablewiththemostinfluenceonVKTisdistancetravelledperdriver,indicatingthatthechangeis

behavioural.However,iftheIDAisfollowedbyaregressionanalysis,onemightbeabletodetermine

whatotheraspectsareaffectingthisshiftinbehaviour,suchasrisinggasprices.Multipleregressions

allowonetoexamineabatteryofothervariableswhichwouldnotbeabletofitintotheIDA,asIDAsare

limitedmymathematicalrules.Byincludingothervariables,wecanexaminemorethoroughlywhatmay

beresponsibleforchangingVKT.


23

Furthermore, IDAs have a specific set of assumptions; if there is a change in one of the

component factors, the IDA assumes that the aggregate variable changes proportionally. In reality

however,thismaynotnecessarilybetrue,andtherelationshipmaybemuchmorecomplicated.Various

variablesmayinteracttoproduceadifferentoutcome.Amultipleregressionismuchmoreflexible,and

can predict VKT in a dynamic, complex environment. Specifically, one can use amultiple regression

analysistoestimatewhethercertainvariablesarestatisticallyrelatedtoVKT,determinewhetherthis

relationshipispositiveornegative,andestimatethestrengthoftherelationship.

The regression analysis, which is limited to Canada, will determine how these variables are

relatedtothedependentvariable,percapitaVKT.Ourvariablesof interest intheregressionaregas

prices,income,theagestructureofthepopulation,andtheshareofpeoplelivinginurbanareas.Even

thoughagestructureisincludedintheIDA,itisimportantthatitalsoincludedintheregressionmodel,

so as to avoidbiased results. In a regression,whenoneomits a variable that is correlatedwith the

independent variable and at least one dependent variable, the model will overestimate or

underestimatetherelationshipforothervariables.Byincludingagestructureintheregression,wecan

avoidthistypeofbiasintheresults.Furthermore,includingsomeofthesamevariablesinboththeIDA

andtheregressionanalysisproducesmorerobustresults,aseachmethodhas itsownstrengthsand

weaknesses.

Asmentionedabove,resultscanbebiasedwhenvariablesareomittedwhicharecorrelatedwith

theindependentvariableandatleastonedependentvariable.Unfortunately,sometypesofvariables

cannotbeobservedormeasured.Thesemightincludefactorswhichdifferbetweenprovinces,butare

heldconstantover time, suchasgeography.For instance,BritishColumbia’smountain rangesmight

requiremore roundabout routes and thus greater driving distances. There are also variableswhich


24

changeovertimebutdonotvarybetweenprovinces,suchasfuelefficiencyofvehicles.Althoughthis

typeofdatadoesnotexistforthepurposesoftheregressionanalysis,westillwanttocontrolfortheir

effect.Conveniently,afixed-effectsregressionanalysiscancontrolfortheseunobserved,unmeasurable

variables,usingalargesetofpaneldata.Paneldata,alsoknownascross-sectionaltimeseriesdata,is

datawhich is observedover timeandbetweenentities, in this caseprovinces. Byusing fixed-effect

regressionanalyses,whichcontrolsfortheeffectsofvariablesthatvarybothovertimeandbetween

provinces,wecanestimatetheeffectofthedependentvariablesonpercapitaVKTmoreaccurately.

Coefficientswereestimatedusingfourvariationsofthesamemodel:apooleddataregression,

province-fixed effects, time-fixed effects, and both province- and time-fixed effects regression. The

province-fixed effects model controls for omitted variables that vary between provinces, such as

geography,butareconstantovertime.Ontheotherhand, thetime-fixedeffectsmodelcontrols for

factorsthatchangeovertimebutaresteadybetweenprovinces,suchasimprovementsinfuelefficiency.

Thepooleddataregression,orastandardlinearmultipleregression,doesnotusetime-fixedorprovince-

fixedeffects,butwasincludedforcomparison.Thefinalmodelvariationusesbothprovince-andtime-

fixedeffects,thusprovidingthemostrobustestimates,asitcontrolsforunmeasuredfactorsthatvary

bothovertimeandbetweenprovinces.Therelationshipsbetweenthedependentvariable,percapita

VKT,andtheindependentvariableswereestimatedusingthefollowfixed-effectsspecification:

𝑙𝑜𝑔(𝑝𝑒𝑟𝑐𝑎𝑝𝑖𝑡𝑎𝑉𝐾𝑇)FG = 𝛽I +

𝛽K𝑙𝑜𝑔 𝑔𝑎𝑠𝑝𝑟𝑖𝑐𝑒 FG+𝛽M𝑙𝑜𝑔 𝑖𝑛𝑐𝑜𝑚𝑒 FG+𝛽M 𝑢𝑟𝑏𝑎𝑛𝑠ℎ𝑎𝑟𝑒 FG +𝛽S 𝑠ℎ𝑎𝑟𝑒𝑎𝑔𝑒𝑑18 − 24 FG +

𝛽Z 𝑠ℎ𝑎𝑟𝑒𝑎𝑔𝑒𝑑65 + FG +𝛿F +𝜆G +𝜀FG.

PercapitaVKTtpispercapitavehiclekilometrestravelledforyeartandprovincep,gaspriceismeasured

asthepriceindexrelativeto2002,andincomeismeasuredasthemedianincome,bothofwhichhave

(4)


25

beencontrolledforinflation.Urbanshareistheproportionofthoselivinginurbancentres,andshares

ofagegroupsincludethosebetweentheagesof18and24,andover65.Otheragegroupswereomitted

toavoidmulticollinearity.Fixed-effectsfortimeandprovincesarerepresentedasδtandλp,respectively,

whileεtprepresentstheerrortermforfactorsnotcapturedinthemodel.LogsofVKT,gasprice,and

incomewereusedtointerpretregressioncoefficientswithmoreease,sothechangeindependentand

independentvariablescouldbeunderstood in termsofpercentages. Logswerenot required for the

urbanoragegroupshares,asthesearealreadypresentedaspercentages.

Certainassumptionsmustalsobemetinordertotrustresultsfromaregressionanalysis.These

are:(a)linearrelationshipsbetweenthedependentandindependentvariables,(b)normallydistributed

residuals, (c) equal variance of residuals across the range of the independent variable, and (d)

independenceofresiduals.Theassumptionofa linearrelationshipwasnotmetperfectlyformedian

income(Appendix1).Attemptsweremadetotransformmedianincomesoalinearmodelcouldproperly

predicttherelationship,buttheywereunsuccessful.Theentiredatasetalsohadmoreoutliersthan

desired(Appendix2),buttheycouldnotberemoved.Allotherassumptionsweremetandareoutlined

inAppendix3.

Althoughthismethodiswidelyused,thoseinterpretingresultsofamultipleregressionanalysis

must be cautious. First of all, missing variables can bias the results. Certain variables have been

controlledforinthefixed-effectsmodel,suchasvariablesthatvarybetweenprovincesbutaresteady

over time, or variables that are constant between provinces but change over time. However, some

variablesarestillnotcontrolledfor,suchasthosewhichchangeovertimeandwithinprovinces.For

instance,someprovincesmayhavebeeninvestinginsmarttransportationandbetterurbandesign,or

BritishColumbiamaybeexperiencedaculturalshiftawayfromcardependency,inpartduetotherecent


26

carbon tax.These factorsmayaffect vehicleuse,but theyarenot controlled for in the fixed-effects

regression.Aswell, snowandweatherevents,oreven localpolicieswhich impactdriving,werenot

included,asthisdatadidnotexist.Asaresult,outputsfromtheregressionmaybeslightlybiased.A

secondkeyconcernisthatregressionanalysescannotnecessarilyexplainwhetheronefactorcausesa

changeintheother,onlythattheyarerelated.Forinstance,theregressioncouldsuggestthatVKTand

thepercentageofpeoplelivinginurbanareasisstronglyrelated.However,itdoesnottelluswhether

peoplearedrivinglessastheymoveintocities,orifpeoplearemovingintocitiesbecausetheydonot

wanttorelyoncartravel.Thisissuecanoftenbesurpassedwithgoodexperimentaldesign,whichallows

onetoestablishcause-and-effectrelationships.

Theregressionresultsestimatehowtwovariablesarerelated,whenallothervariablesareheld

constant.Inrealityhowever,thevariablesarechangingindependentlyofoneanother.Wewanttoknow

whatisresponsibleforchangesinVKT,inadynamicsituationwheremultiplevariablesarechanging.

Using estimates from the regression analysis, counterfactual scenarios were simulated in order to

determinewhatamountofchangeinVKTwasduetochanges incertainvariables.Specifically,three

counterfactualscenarioswereestimated;oneinwhichgaspriceswerefixedattheir1999level(Figure

1),oneinwhichincomewasfixedatits1999level(Figure2),andoneinwhichtheproportionofage

groupswasfixedto1990proportions(Figure3).


27

Figure 1. Gas prices, for the counterfactual scenario in which gas prices are fixed at the 1999 price, and for observed conditions, averaged across all ten provinces.

1.0

1.2

1.4

1990 1995 2000 2005 2010year

Gas

Pric

e In

dex

Rel

ativ

e to

200

2 (in

200

2 do

llars

)Gas Price Scenario

40000

42500

45000

47500

1990 1995 2000 2005 2010year

Med

ian

Inco

me

(in 2

002

dolla

rs)

Income Scenario

Figure 2. Median income, for the counterfactual scenario in which income is fixed at its 1999 level, and for observed conditions, averaged across all ten provinces.


28

For each of these scenarios, the other variables behaved normally and followed their real life

trajectories,allowingustoestimatewhatamountofchangeinVKTwasduetogasprices,income,and

shifts in demographics. Inmany countries, the “peak” in vehicle use occurred around 2004, but to

accountforalaginbehaviour,gaspricesandincomeinthecounterfactualscenarioswerefixedin1999,

andaveragedacrossalltenprovinces.Itwasalsoaroundthelate1990swhengaspricesandincome

began steadily increasing (Figure 1; Figure 2). Because age proportions were increasing steadily

throughouttheperiodfrom1990to2013,theagegroupsarefixedin1990,ratherthan1999(Figure3).

The regression with both time- and province-fixed effects was employed to estimate the

counterfactualscenariosforgaspriceandagegroups.However,theeffectofmedianincomewasnot

significantfortheregressionwithbothprovince-andtime-fixedeffects,sothetime-fixedeffectsmodel

wasusedinstead.

Figure 3. Proportions of age groups, for the counterfactual scenario in which age groups are fixed at their 1990 proportions (red and orange), and for observed conditions (black and grey), averaged across all ten provinces.

10

12

14

16

1990 1995 2000 2005 2010year

Pro

porti

on o

f Peo

ple

in A

ge G

roup

Age Proportion Scenario


29

DataSources Multiplesourcesofdatahavebeencompiledfortheanalyses.InCanada,theOfficeofEnergy

Efficiency at the Ministry of Natural Resources Canada provides aggregate-level data on vehicle

kilometers travelled from 1990 to 2013 for each province. In the United States, this information is

providedbytheOfficeofHighwayPolicyInformationattheU.S.DepartmentofTransportation.Only

carsandlighttrucks(lessthan4.5tonnes)wereconsideredintheanalysis.Vehiclekilometrestravelled

werethencalculatedonapercapitabasis.InCanada,populationestimateswereprovidedbyStatistics

Canadaonayearlybasisfrom1990to2013.IntheU.S.,nationalpopulationestimatescamefromthe

U.S.CensusBureau.

TheCanadianVehicleStudysurveyedCanadianhouseholdsfrom2000to2009usingdiaryentries

totrackvehicletravel,includingdistancetravelledbydriveragegroup.Datafrom2001istoounreliable

forthepurposesoftheIDA,andmissingdatafordriversaged16to20wasimputedfor2004,2005,and

2006.Althoughitwouldhavebeenfruitfultodecomposetraveltrendsoveralongerperiodoftime,the

statisticalmethodsoftwootheravailableCanadiantravelsurveysdifferedinsuchawaythatcomparison

acrosssurveyswasnotpossible.

Data on American vehicle usewas collected from the comprehensive and data-richNational

HouseholdTravelSurvey,availablefor2001and2009,andthe1995NationalPersonalTransportation

Survey,bothfromtheFederalHighwayAdministrationattheU.S.DepartmentofTransportation.Both

surveysaredesignedtobecomparedoveryearsandbetweensurveys,andemploysimilarmethodsof

householddiaryentriestotracktravelbehaviour(U.S.DepartmentofTransportation2009).Theyinclude

dataonagegroupsofdrivers,andvehiclekilometrestravelledperdriver.


30

InCanada,numberoflicenseddriversperagegroupisonlyavailableattheprovinciallevel.Data

was provided by provincial licensing agencies and transportation ministries in Quebec, Manitoba,

Ontario,Alberta,Saskatchewan,andNewBrunswick,whichwereusedtoimputelicensesatthenational

level.IntheU.S.,theOfficeofHighwayPolicyInformationprovidesnationaldataonlicenseddrivers.

PanelleveldatafortheregressionanalysescamefromStatisticsCanadaandNaturalResources

Canada.Specifically,vehiclekilometrestravelledfrom1990to2013wereprovidedbyNaturalResources

Canada, while population estimates, gas price indices andmedian income levels were provided by

StatisticsCanada,between1990and2013.Inflationwascontrolledusing2002realdollartermsforgas

priceconsumer indexandmedian incomes.Alldatawasavailableonanannualbasisexcept for the

percentageof thepopulation living inurbanareas,which is collectedevery fiveyearsaspartof the

census.Accordingly,intercensaldataonurbanpopulationswaslinearlyestimated.

VehiclekilometrestravelledforBritishColumbiaandthethreeterritorieswerecombined,while

othervariables,suchas incomeandgasprices,werenot.Althoughthiscouldbiastheestimates,the

effectshouldlikelybesmall,astheshareofdrivinginCanada’sterritoriesislimitedincomparisonto

provinces,especiallygiventhelongwinters,smallpopulation,andthemanytownswithoutroadaccess.


31

RESULTSDecompositionofVehicleUseinCanada&theUnitedStates OverallTravelDemand Asdiscussedelsewhere(NewmanandKenworthy2011;Kuhnimhofetal.2012;Millard-Balland

Schipper2011),AmericanpercapitaVKTwasrisingsteadilyfordecadesuntiltheearly2000s,whenit

unprecedentedlyplateauedandbegantodecline(Figure4).Sincethen,therehasbeenaslightupturn

invehicleuseintheUnitedStatesin2014and2015,whichmayormaynotindicatearecoveryinthe

growthofvehicleuse.

Percapita,CanadiansdrivefarlessthanAmericans.In2013,Canadiansdrovejustafractionof

what Americans drove, approximately equal American vehicle distance in 1970 (Figure 4). More

importantly,thepatternofdecliningorplateauingvehicleuseismuchmoremutedinCanadacompared

totheU.S.(Figure4).

Figure 4. Per capita vehicle kilometres travelled in Canada from 1990 to 2013 and in the United States from 1970 to 2015.

0

5000

10000

15000

1970 1980 1990 2000 2010Year

Veh

icle

Kilo

met

res

Trav

elle

d P

er C

apita

(km

)

CountryCanada

USA


32

Thisisfardifferentfromthepatternsexhibitedinotherdevelopedcountries,suchastheU.K.

andGermany,whichsawanunprecedentedchangeinpercapitavehicleuseattheturnofthemillennia

(Metz2010;Headicar2013;Kuhnimhofetal.2012;NewmanandKenworthy2011).Whatmaybemore

striking however, is the lack of extreme growth in vehicle use in Canada in the 1990s and earlier,

demonstratedintheUnitedStates.

Inisolation,itdoesappearthatCanadamayhaveexperiencedamodestpeakinpercapitavehicle

useintheearly2000s(Figure5).Thispatternisquitevariable,andwithoutlongertermdata,itisdifficult

tounderstandtrendsinCanadianvehicleusefully.

Although it is difficult to draw conclusions from the overall national trend in Canada, it is

noteworthy thatpatternsdiffer substantiallybetweenprovinces (Figure6). Someof the variation in

Figure 5. Per capita vehicle kilometres travelled in Canada from 1990 to 2013. The trend line is represented in red.

8700

8900

9100

9300

1990 1995 2000 2005 2010Year

Veh

icle

Kilo

met

res

Trav

elle

d P

er C

apita

(km

)


33

vehicle kilometres travelled at the national level could be the result of different, or even diverging,

patternsattheprovinciallevel.

Forinstance,BritishColumbiaandAlbertashowacleardeclinestartinginthelate1990s,while

PrinceEdwardIsland,Saskatchewan,Newfoundland,andtosomeextentManitoba,showtheopposite.

Alternatively,percapitavehicleuseinNovaScotia,Ontario,andQuebecappearstohaveplateaued,if

notinthe1990sthanintheearly2000s.Datawasnotreadilyaccessibletoconductasimilarstate-by-

statecomparisonfortheU.S.

Figure 6. Per capita vehicle kilometres travelled for each province, from 1990 to 2013. British Columbia and the territories are combined.

6000

8000

10000

12000

1990 1995 2000 2005 2010Year

Veh

icle

Kilo

met

res

Trav

elle

d P

er C

apita

(km

)

provAlberta

British Columbia

Manitoba

New Brunswick

Newfoundland and Labrador

Nova Scotia

Ontario

Prince Edward Island

Quebec

Saskatchewan


34

DecompositionAnalysis:UnitedStates

TrendsinAmericanvehicleusearedecomposedinFigure7,from1995to2009.

Inbothperiods, totalVKTwas increasing,although toamuch lesserextent in2001-2009 (Figure7).

Duringthe1995-2001period,individualcaruse,measuredasVKTperdriver,wasgrowing(Figure7).

ThisisconsistentwithoveralltrendsofpercapitacaruseseenintheUnitedStates(Figure4).Thelargest

contributing factor to increasingVKT from1995-2001was population growth,whichwas exerting a

strong,positiveinfluence(Figure7).Conversely,between2001and2009,totalVKTwasstillincreasing,

buttoamuchlesserextent,whiledistancedrivenperdriverwasdecreasing(Figure7).Between2001

and2009,forthefirsttimeindecades,Americandriversdroveless,representingtheunprecedented

changeinvehicleusedescribedinFigure4.Thisisconsistentwithotherresearch,whichfoundaturn-

Figure 7. American vehicle trends decomposed from 1995 to 2009, demonstrating the relative contributions of population growth, changes in age structure, changes in the proportion of licensed drivers, and the distance driven per licensed driver, as well as the total change in VKT.

-500000

-400000

-300000

-200000

-100000

0

100000

200000

300000

400000

500000

PopulationGrowth DemographicChange

LicensingRate VKTperDriver TotalChange

1995-2001

2001-2009


35

aroundinpersonalvehicleusebeginningintheearly2000s(PuentesandTomer2008;Kuhnimhofetal.

2008).Likethefirstperiod,populationgrowthwasexertingastrong,positiveinfluenceonVKT,offsetting

the decline in individual driving (Figure 7). One could infer that population growth was likely a

contributingfactortothestronggrowthinpersonalvehicleuseseeninthe1990sandearlier.During

bothperiods,licensingrateshadlittletonoeffect,asdiddemographicchanges(Figure7),eventhough

babyboomersbeganreachingretirementduringthesecondperiod.

DecompositionAnalysis:Canada

InCanada,thedecompositionofvehicleuseappearstobequitesimilartotheUnitedStates.

However,becausetrendscouldonlybeanalysedforamuchshorterperiod,changesinvehicleuseare

muchlessclear.Nonetheless,yearly(Figure8)andperiod-wise(Figure9)decomposedtrendsstillshed

lightonvehicleuseinCanada.

Figure 8. Canadian vehicle trends decomposed on a year-to-year basis from 2000 to 2009 (omitting 2001), demonstrating the relative contributions of population growth, changes in age structure, changes in the proportion of licensed drivers, and the distance driven per licensed driver, as well as the total change in VKT.

-15000.0

-10000.0

-5000.0

0.0

5000.0

10000.0

15000.0

2002 2003 2004 2005 2006 2007 2008 2009

PopulationGrowthDemographicChangeLicensingRate

VKTperDriver

TotalChange


36

LiketheU.S.,populationgrowthwashavingapositiveinfluenceonoverallvehicleuseinCanada,

whiletheeffectofdemographicchangewasveryminimal(Figure8;Figure9).Changesinlicensingrates,

thoughmorevariableovertheperiod,stillappeartohaveasmalleffectoverall(Figure8;Figure9).On

ayear-to-yearbasis,individualcaruse,measuredasVKTperdriver,hasamuchmoreambiguouspattern,

fluctuatingbetweengrowthanddeclineovertheperiodof2000to2009(Figure8).VKTperdriverwas

havinganotablenegative influenceonoverallVKTuntil2006,when individualvehicleuse increased

(Figure 8). It then fell again, but rebounded soon afterwards. Because American trends cannot be

decomposedonayeartoyearbasis,wecannotdeterminewhetherthisvariabilitywasalsothecasefor

theU.S.Inaddition,thevariabilityseeninCanadianVKTperdrivermaybereflectiveofthefactthatper

capitavehicleusedidnotchangeasdramaticallyduringthisperiod(Figure4),unliketheU.S.,whichsaw

a clearperiodof growth followedby a clearplateauor evendecline.However,whenaperiod-wise

decompositionisconductedforCanada,thetrendismuchmoresimilartotheUnitedStates(Figure9),

-40000.0

-30000.0

-20000.0

-10000.0

0.0

10000.0

20000.0

30000.0

40000.0

PopulationGrowth

DemographicChange

LicensingRate VKTperDriver TotalChange

Figure 8. Canadian vehicle trends decomposed for the period of 2000 to 2009, demonstrating the relative contributions of population growth, changes in age structure, changes in the proportion of licensed drivers, and the distance driven per licensed driver, as well as the total change in VKT.


37

whereVKTperlicenseddriverishavingthelargestnegativeinfluenceontotalVKT.Thissuggestthatin

bothCanadaandtheU.S.,themainfactorresponsibleforrecentchangesvehicleuseisabehavioural

shift,wherepeoplearedrivingless.

Anexaminationofvehicleuseandlicensingratesamongagegroupsmayshedmorelightonto

individualdrivingbehaviour.Whenvehiclekilometresdrivenperlicenseddriverisbrokendownbyage

group,itappearsthatyoungdriversundertheageof24havehadthelargestnegativecontribution,both

inCanadaandtheUnitedStates(Figure10).YoungadultsinCanadadrivesubstantiallylesseachyear

than theirAmerican counterparts. InCanada,25 to44-yearoldsarealso reducing their vehicleuse,

althoughthisdoesnotappeartobethecaseintheU.S(Figure10).Ontheotherhand,inbothcountries,

seniorsincreasedtheircaruseduringthisperiod,whichisparticularlyapparentamongCanadianseniors

(Figure10).

Intermsoflicensingrates,theshareoflicenseddriversundertheageof24andover65ismuch

lowerthantherestofthepopulation,bothintheU.S.andCanada(Figure11).Althoughlicensingrates

5000

10000

15000

20000

25000

1995 2000 2005 2010Year

Tota

l Kilo

met

res

Trav

elle

d P

er L

icen

sed

Driv

er (k

m)

CountryCanada

USA

Age.Group16-24

25-44

45-64

65+

Figure 10. Total vehicle kilometres per licensed driver, by drivers’ age group, in Canada (2000-2009) and the United States (1995-2009).


38

didnothaveasignificanteffectonaggregateVKT,itisnonethelessquiteclearthatintheUnitedStates

since1995,thelicensingrateforseniorswasrapidlygrowing,whilefallingforyoungadults(Figure11).

EffectsofGasolinePrice,Income,andUrbanization Accordingtothedecompositionanalysis,themainfactorresponsibleforplateauingordeclining

vehicleuseisachangeinbehaviour,wherepeoplearedrivingless,particularlyyoungadults.However,

itisnotclearwhatisresponsibleforthisshiftinbehaviour.Aregressionanalysiscantellushowgasoline

prices, income,andurbanizationareaffectingdrivingbehaviour.Table1displaysregressionanalyses

resultsforallfourmodels,thepooledregression(column1),province-fixedeffects(column2),time-

fixedeffects(column3),andbothtime-andprovince-fixedeffects(column4).Theprovince-fixedeffects

modelcontrolsforvariableswhichvarybetweenprovincesbutareconstantovertime,whilethetime-

fixedeffectsmodelcontrolsforvariableswhichvaryovertimebutareconstantbetweenprovinces.The

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1995 2000 2005Year

Sha

re o

f Lic

ense

d D

river

s CountryCanada

USA

Age.Group16-24

25-44

45-64

65+

Figure 11. The share of licensed drivers, by drivers’ age group, in Canada (2000-2009) and the United States (1995-2009).


39

modelwithbothfixedeffects(column4)providesthemostrobustestimates.TheadjustedR2values

varybetween0.58and0.77,indicatingthatthemodelspredictthedatawell.

Estimates from the regression suggest that elasticities of per capita vehicle kilometres with

respecttogasolinepricevarybetween-0.12to-0.72,withthelatterestimatedfromthemostrobust

model.Thisissomewhathigherthanrecentestimatesofelasticitiesofdrivingdemandwithrespectto

gaspricesfoundintheliterature,whichvaryaround-0.1or-0.2(Gillinghametal.2015;Gillingham2014;

Barlaetal.2009).Thedivergencemaybeduetothesimplicityofthemodel;specifically,variableswhich

influencevehicleusemayhavebeenomitted.Forinstance,variableswhichchangeovertimeandwithin

provincesareomitted,asarelocalpoliciesandweatherandsnowevents.

Table 1. Multiple regression results for a pooled model, province-fixed effects model, time-fixed effects model, and both province- and time-fixed effects model, using per capita vehicle kilometres travelled as the dependent variable.


40

InordertodeterminehowgaspriceshaveinfluencedVKTinthelast25years,acounterfactual

scenariowas estimated inwhich gas priceswere fixed at their 1999 price (Table 2; Figure 12). The

predictedscenariowithobservedvariables(Table2,row2)isaveryclosefittotheobserved,realpattern

inVKT(Table2,row1),indicatingthatthepredictionsfromthecounterfactualscenarioarerobust.

CounterfactualScenario PerCapitaVKTin2013

%DifferencefromObservedScenario

Observedbaselinecondition 9014.86 --Predictedscenariowithobservedvariables

8738.73 -3.06

Fixedgasprice 12825.40 42.27

Figure 12. Per capita VKT from 1990 to 2013 under observed conditions, under a predicted scenario with observed changes in variables, and a scenario in which gas prices are fixed at their 1999 prices.

9000

10000

11000

12000

13000

1990 1995 2000 2005 2010year

percapitaVKT

Fixed Gas Price

Table 2. Estimates of per capita VKT in 2013, as well as percent divergence from the observed 2013 per capita VKT, using counterfactual scenarios from the fixed-effects regression model in which gas prices are fixed at the year 1999.


41

From1990to2013,percapitaVKTincreasedby2.56%,reaching9014kmtravelledperpersonin

2013.Duringthistime,inflation-controlledgaspricesinCanadagrewbyapproximately38%,peakingin

2008.However,accordingtothecounterfactualscenario,ifgaspriceshadstayedattheir1999levels,

percapitaVKTwouldhaveincreasedto12825.4kmperperson,42%higherthantheobservedpercapita

VKT(Table3;Figure12).Thissuggeststhatthesteadyincreaseingaspricesinthefirstdecadeofthe21st

centurydiscourageddrivinginCanada.Ifgaspriceshadnotrisen,butallothervariableshadincreased

astheydid,percapitaVKTwouldhavelikelyincreasedsubstantially.

Theincomeelasticityofvehicleuseisestimatedtobebetween0.34and0.87forthepooled,

province-fixed,andtime-fixedeffectsregression,butisinsignificantinthemodelwithbothprovince-

andtime-fixedeffects.Barlaetal.(2009)estimatedaGDPelasticityofdrivingdemandof0.2to0.3in

Canada,whichisreflectiveofourprovince-fixedeffectsestimation.ThemodelusedinBarlaetal.(2009)

wasmuchmorecomplex,andcouldcapturemuchmorevariation inGDP.Contrarily,ourmodelwas

muchmoresimple,andusedmedianincome,whichhasnotvariedmuchoverthelast25years.Mostof

theincomevariationinCanadaisbetweenprovinces,ratherthanovertime.Forthisreason,themodel

cannot easily assess the influence ofmedian incomewith respect to per capita VKT, as variation in

income is small. However, given that the relationship between income and per capita VKT is very

significantforpooled,province-fixed,andtime-fixedeffectsregressions,wecanbequitecertainthat

income is having some effect on per capita VKT. As well, as discussed in the previous section, the

assumption of a linear relationship between the independent and dependent variables is not met

perfectlywithincome,makingresultsforincomeelasticitylesstrustworthy.


42

In order to determine how income has influenced VKT in the last 25 years, a second

counterfactualscenariowasestimated,withincomefixedin1999(Table3;Figure13).Sincetheeffect

of income is insignificant for the regression with both time- and province-fixed effects, the

counterfactual scenario for income was estimated using the time-fixed regression. As a result, the

predictedscenariowithobservedvariables(Table3,row2)isanotascloseafittotheobserved,real

patterninVKT(Table2,row1),comparedtothepreviouscounterfactualscenario.However,thefitis

stillrelativelyaccurate,andconclusionscanstillbedrawn.

CounterfactualScenario PerCapitaVKTin2013



8181.93 -9.24

Fixedincome 6793.76 -24.64

Table 3. Estimates of per capita VKT in 2013, as well as percent divergence from the observed 2013 per capita VKT, using counterfactual scenarios from the time-fixed regression model in which income is fixed to its 1999 level.

Figure 13. Per capita VKT from 1990 to 2013 under observed conditions, under a predicted scenario with observed changes in variables, and a scenario in which income is fixed at its 1999 level.

7000

7500

8000

8500

9000

1990 1995 2000 2005 2010year

percapitaVKT

Fixed Income


43

From 1990 to 2013, median income in Canada increased by roughly 19%. According to the

counterfactualscenario, if incomehadstoppedgrowingafter1999,percapitaVKTwouldhavebeen

almost25%lowerthanobserved,decreasingto6793kmperperson(Figure13).Thissuggestthatincome

ishaveastrong,positiveinfluenceonpercapitaVKT,pushingvehicleuseupwardsasitgrows.

Intermsofurbanization,whenallotherfactorsareheldconstant,theelasticityofpercapitaVKT

with respect to increasingurbanpopulation appears to be -0.012 for pooled and time-fixedmodels

(Table1),indicatingasmalleffectofurbanization.However,therelationshipbetweenpercapitaVKT

andtheshareofurbandwellersisinsignificantinprovince-fixedeffectmodelandthemodelwithboth

province-andtime-fixedeffects.Forthisreason,acounterfactualscenariowasnotestimatedforthe

effectofgrowingurbanization inCanada.Like income, the insignificanceof therelationshipmaythe

resultoflowvariabilityfortheshareofpeopleresidinginurbanareas,orotherreasonswhicharefurther

reviewedinthediscussionsectionbelow.

Accordingtothefixed-effectsregressionmodels,percapitaVKTelasticitieswithrespecttothe

18-24agegroupvariesbetween-0.039to-0.088,whiletheover65agegroupisinsignificantlyrelated

topercapitaVKT.Inacounter-factualscenarioinwhichbothagegroupsarefixedin1990,percapita

VKTwas5.41%lowerthantheobservedpattern(Table4;Figure14).


44

The regression results and counterfactual scenario for age groups suggest that demographic

changehashadaminimalimpactonvehicleuseinCanada,whichisconsistentwithresultsfromtheIDA.

CounterfactualScenario PerCapitaVKTby2013



8738.73 -3.06

Nochangeinagestructure 8527.42 -5.41

Table 4. Estimates of per capita VKT in 2013, as well as percent divergence from the observed 2013 per capita VKT, using counterfactual scenarios from the fixed-effects regression model in age structure is fixed in 1990.

Figure 14. Per capita VKT from 1990 to 2013 under observed conditions, under a predicted scenario with observed changes in variables, and for a scenario in which both age groups are fixed in 1990.

8700

9000

9300

1990 1995 2000 2005 2010year

percapitaVKT

Fixed Age Proportions


45

DISCUSSIONComparisonsBetweenCanadaandtheUnitedStates

Likemany other OECD countries (Millard-Ball and Schipper 2011), American vehicle use has

changedoverthelast15years,unprecedentedinmanydecades.Canadaisunusualcomparedtoother

countries,inthatthechangeindrivingtrendsisquitemoderate.Furthermore,theyearlypercapitaVKT

issubstantiallylowerinCanadathanintheUnitedStates.ItisunclearwhyoveralltrendsinCanadadiffer

fromothercountries,yetaccordingtothedecompositionanalysis,thefactorsresponsibleforelevating

anddampeningVKTarecomparablebetweenCanadaandtheU.S.

Individualdrivingpreferencesappeartofavourlessvehicleuseafter2001intheU.S.andinmost

years inCanadabetween2000and2009.Drivingpatternsamongagegroupsalsoappeartobevery

similar between the two countries, as discussed in the next section. Likewise, in both countries,

populationgrowthconsistentlypushedvehicleuseupwards,whilelicensingrateshadalmostnoeffect.

Giventhestronginfluenceofpopulation,onemightaskwhetherthedifferencebetweentheU.S.and

Canadacouldbeattributedtodifferences inpopulationsize.AlthoughtheUnitedStateshasamuch

higherpopulation,thegrowthratehasbeenrelativelycomparablebetweenthetwocountries.Likewise,

the U.S. is much wealthier than Canada, and differences could be the result of different incomes.

However, like population, the growth rates of income and GDP have been relatively comparable

betweenCanadaandtheUnitedStates.Nonetheless,populationandincomeareworthwhileconcepts

toexamineinfutureresearch.GaspricescouldalsoexplaindifferencesbetweenvehicleuseinCanada

andtheU.S.,althoughgasolinepricesaresetbytheinternationalmarket,andshouldbecomparable

betweencountries,albeitwithsomevariationduetolocalpoliciesandtaxes.Thebuiltenvironment,

specificallyurbanandsuburbansprawl,mayalsohelptoexplainwhyCanadianpercapitadrivingismuch


46

lowerthantheU.S.,althoughthishasnotbeenstudiedexplicitly.Anotherpossibleexplanationforthe

differencecouldbethatCanadahitaplateauinvehicleusemuchearlierthanothercountries,before

the 1990s, althoughwithout long-term data, this cannot be proven. Aswell, themore pronounced

differenceindrivinghabitsbetweenyoungadultsandseniors,comparedtoAmericanagegroups,could

becounteractingeachotherandproducingaflattertrendoverall.

StructuralFactorsResponsibleforChangingVehicleUse DrivingTrendsAmongAgeGroups Previously, seniors typically drove less, as they no longer commuted towork or shepherded

around their children once retired (US EIA 2013; Dutzik and Baxandall 2013). However, today older

CanadiansandAmericasaredrivingmorethatevenbefore.Onepossiblereasonfortheincreasemaybe

theresultoflengtheninglifeexpectancies,whereseniorsarelivingmoremobile,healthier,andlonger

lives(StatisticsCanada2012;Metz2012).Inaddition,thecurrentgenerationofseniorswouldhavebeen

borninthe1940sorearlier,andmostwouldhaveactivelyparticipatedinthe“loveaffairwiththecar,”

whichdominatedtraveltrendsinNorthAmericafordecades.Thus,theincreaseindrivingamongseniors

couldbeexplainedbythemostcar-dependentadultsreachingretirement,whoareincreasinglyliving

longer,healthierlives.

Learningtodrivewasconsideredanimportantriteofpassageforteenagers,andowningacar

wascriticaltoadulthood(Goodwin2012A).Yettoday,thelargestnegativecontributorstovehicleusein

CanadaandtheU.S.areyoungadults,whoaredemonstrablydrivinglesseachyear.Thispatternisalso

observedinmanyEuropeancountries(Kuhnimhofetal.2012;2013;GoodwinandVanDender2013).

Youngadultsareenteringtheworkforcemuchlatercomparedtopreviousgenerations,asmoreyouth

arenowattendinguniversityandstrugglingtosecurejobsandstablecareers(Kuhnimhofetal.2012).


47

Aswell,mostyoungwomenarenowpursuingtheirowncareers(Gilletal.2014),delayingmarriageand

the “settlingdown”of young couples (Statistics Canada2014),which in thepast oftennecessitated

owningacar.Forexample,todaytheaveragemarryingageisaround30,whilein1971itwasaround23

(Roberts2005).Furthermore,Canadahasexperiencedawideningincomegapbetweenyoungandolder

Canadianswithin the last30 years (Gill et al. 2014). The regression results indicate that incomehas

exhibitedapositiveinfluenceonvehicleuse,andthusthesamemustbetruewithdecliningincomeand

decliningcartravelamongyoungadults.

Onecouldarguethatsincetheproportionofyounglicenseddrivershasnotchangedsignificantly

overthelastdecade,perhapsyoungadultsintendtoeventuallyfollowinthefootstepsoftheirparents’

heavycaruse,despiteeconomicuncertainties.Ontheotherhand,ifattitudestowardsthecarareinfact

changing,onecouldsaythattherelativelystablelicenseratecouldberesidualeffectsofastrongcar

culture which lasted for the better half of the century. Either way, habits and practises that are

developed in early adulthood are often kept for a lifetime. For instance, a strong predictor of an

individual’slikelihoodtovoteiswhethertheyvotedinelectionsduringearlyadulthood(Coppockand

Green2015).Ifthisisalsotruefordrivingbehaviour,wemayseelessdrivingbymiddle-agedadultsin

thenextfewdecades,asthecurrentgenerationofyoungadultsgrowsolder.

AnAgingPopulation

Previously, we hypothesized that the aging Canadian population could be playing a role in

declining vehicle use, since older drivers, who are growing in numbers, were thought to drive less

comparedtoyoungerpeople.Accordingtobothdecompositionandregressionanalyses,demographic

shiftsareplayingaverysmallrole.Kuhnimhofetal.(2013)alsofoundthatagingpopulationsplayeda

smallroleindrivingpatternsoffourwesterncountries.InCanada,theshareofseniors,whoaredriving


48

more,isincreasinginCanada,whiletheshareofyoungadults,whoaredrivingless,isshrinking.These

twocoupledtrends,ofbothshiftingdemographicsandvehicleusewithinagegroups,couldbetogether

reducingvehicleuseinCanadaandabroad,ratherthansimplychangesindemographicsonitsown.

Urbanization

GrowingurbanpopulationsandthedensificationofcitiescouldalsobeplayingaroleinCanadian

vehicle use, as it has in other countries (Headicar 2013;NewmanandKenworthy 2011;Metz 2013;

GoodwinandVanDender2013).Canadaisbecomingincreasinglyurbanized;81%ofCanadiansnowlive

incities,withOntario,BritishColumbia,Albertahostingthelargesturbanpopulations(Employmentand

SocialDevelopmentCanada2016B).Interestingly,thelattertwoprovinceshavethemostpronounced

decline in vehicle use. Unfortunately, data did not exist to decompose driving demand in terms of

urbanization.However,resultsfromtheregressionanalysissuggestgrowingurbanizationishavingno

effectonpercapitavehicleuse.Thisdiffersfromtheexpectednegativecontributionofurbanization,

which isdiscussedextensively in the literature (Headicar2013;NewmanandKenworthy2011;Metz

2013;GoodwinandVanDender2013).However,CanadiancitiesareverydifferentfromEuropeanones,

where thebulkofpeak car researchhasbeenconducted (Kuhnimhofetal. 2012;2013;Metz2013;

Headicar 2013). Although cities such as Toronto, Vancouver, andMontreal have large public transit

systems,otherurbancentresstillhaverelativelylimitedoptions.Evenifgaspricesarehigh,orpeople

desiretodriveless,vehicleusewillstillberelativelyinelasticinareaswithoutreliablealternativeforms

oftransportation.Furthermore,manyCanadiancitiesarelockedintoalegacyofurbansprawl,especially

newercitiesorthosewhichexperiencedmassivepost-warbooms.Sprawlingcitiesrequirevehicletravel

forevenshorttrips(KenworthyandLaube1996).Consequently,thosethatregisterasurbandwellersin

theCanadianCensusmayinfactbelockedintoareasstillrequiringheavyvehicleusewherethereare


49

fewalternativetransportationoptions.Moreover,densecitieslikeTorontoandMontrealhavealways

hadrelativelylowvehicleusetobeginwith(KenworthyandLaube1996),andthusmayhavenotreduced

car demand noticeably over the last two decades. This is especially notable given that one third of

Canadians live in Toronto,Montreal, and Vancouver (Employment and Social Development Canada

2016B).Finally,theshareofpeoplelivinginurbancentreshaschangedverylittleovertheperiodof1990

to2013,makingitdifficultfortheregressiontomeasureanyinfluenceofurbanization.Theinabilityto

include urbanization in the index decomposition analysis creates amajor limitation, and should be

consideredforfutureresearch,aswellasfordatacollectionwithrespecttovehicleuse.Furthermore,

definitionsofurbandwellingtypesshouldbeexpandedtoseparatesuburbanfromurbansettlement

areas.

AfactorthatisclearlyresponsiblefordecliningvehicleuseinCanadaisabehaviouralchange,

wherebydriversareactivelydrivingless.Thismaybeduetoeconomicfactors,gasprices,orotherwise.

Theseideaswillbefurtherexploredinthenextsection.

BehaviouralFactorsResponsibleforChangingVehicleUse

AlthoughCanadahasnotexhibitedadramaticchangeinvehicleuseoverallcomparedtoother

countries,provincesdiffersubstantially.Someprovinceshaveexperiencedasignificantdeclineinper

capita car travel since the 1990s, such as British Columbia and Alberta, while other provinces

experiencedarapidincrease,suchasSaskatchewan.Unfortunately,duetodatalimitations,itwasnot

possibletodoadecompositionanalysisforeachprovince.Nonetheless,theseprovincialvariationscould

beduetolocaleconomicconditions,urbanandruralspatialpatterns,andlocalpoliciesandtaxes.Results

from the regression analysis may provide some clues as to why some provinces in Canada are so

markedlydifferentwithrespecttovehicleuse.


50

TheEffectofGasPrices

Basedonthecounterfactualscenarios,CanadianpercapitaVKTwouldhavebeen42%higherhad

gaspricesnotrisenroughly59%from1999to2013.Thissuggeststhatgaspriceswereatleastpartly

responsibleforthedeclininggrowthinCanadianvehicleuseaftertheturnofthemillennia.However,as

mentionedpreviously,changesinvehicleuseinCanadaarenotveryclearwithoutlongertermdata.For

instance,itwouldhavebeenusefultoknowhowgaspricesinfluencedVKTovertheperiodofgrowth

beforetheturnofthe21stcentury,yetthisdataisnotavailable.Nonetheless,gaspricesmayexplain

somedifferencesbetweenprovinces,aspricesvarysignificantlybetweenjurisdictionsinCanada.

BritishColumbia experienceda 51.23% increase in gasprices from1990 to2013, the largest

increaseinCanadaovertheperiodofstudy.In2008,BritishColumbiaimplementedacarbontax,now

pricedat$30pertonneofcarbondioxideequivalentperyear,whichhasresultedinhigherpricesatthe

gaspump.Duringthisperiod,nootherprovinceshadsignificantcarbonpricingmechanismsinplace.

From2008to2011,greenhousegasemissionsinB.C.fellby10%comparedtotherestofthecountry

(ElgieandMcClay2013),andby2013,useoffuelssubjecttothetax,includinggasoline,declinedbyover

16%withintheprovince,and19%relativetotherestofCanada(PedersenandElgie2015).Infact,Rivers

andSchaufele(2013)foundthat inthefirst fouryearsofB.C.’scarbontax,carbondioxideemissions

from gasoline consumptionwere reduced by 3.6million tonnes. According to our results, B.C. also

experiencedoneofthelargestdeclinesinpercapitacaruse,dropping15.7%between1990and2013.

Accordingtothecounterfactualscenario,ifgaspriceshadnotincreasedaftertheyear1999,percapita

VKTinB.C.wouldhaverisendramatically(Figure15).Ofcourse,theeffectofgaspricesondrivingtrends

inB.C.cannotbeprovedwithcertainty,buttheresultssuggestatleastsomeeffect.


51

ThecaseofAlbertademonstratesthattheshiftincarusecannotbetheresultofhighergasprices

alone.Albertasawa23%declineinpercapitadrivingfrom1990to2013,thelargestinCanada.However,

over this period, Alberta had the smallest percent change in gas prices, increasing by only 20.5%.

Althoughgaspricesmaynotalwaysbeakeyfactor indrivingtrends, futurecarbonpricingsettobe

implementedinAlbertaandOntariowillprovidefurtheropportunitiestoassesstheeffectsofcarbon

taxesonvehicleuse.

TheEffectofIncome

PreviousresearchintheU.S.andU.K.suggestthatthe“peakcar”declineisunlikelyrelatedto

income,asvehicleuseandGDPbegantodecoupleinthelastdecade(Millard-BallandSchipper2011;

U.S.EIA2014;Metz2012;Metz2013;LeVineetal.2009).Aswell,thedownturninAmericanvehicleuse

occurredbeforethe2008recession(Figure1).Intermsofincome,ourresultsarerelativelyinconclusive,

7000

8000

9000

10000

11000

1990 1995 2000 2005 2010year

vkt/total.population

Figure 15. Per capita VKT in British Columbia from 1990 to 2013 under observed conditions, under a predicted scenario with observed changes in variables, and for a scenario in which gas prices are fixed in 1999.


52

althoughthreeofthefourregressionssuggestthatincreasingincomeisexertingapositiveinfluenceon

percapitaVKT,pushingvehicleuseupwardssomewhat.However,astherelationshipbetweenincome

andpercapitaVKTisnotlinear,regressionresultsmaybebiased.

GiventhatincomeislikelylinkedtochangesinVKT,financialpressuresforyoungadultscouldbe

playingaroleintheobserveddeclineindrivingforthatagegroup,asdiscussedpreviously.Althoughit

wasnotquantifiedinthisstudy,theeffectofdecliningincomeforyoungadultsisanimportantfuture

areaofresearch.ThisisparticularlynotableasCanadahassomeoftheworstintergenerationalincome

disparitycomparedtoothersimilarcountries(Gilletal.2014).

Theeffectofincomecouldalsoaccountforsomedifferencesbetweenprovinces.Saskatchewan

sawenormousgrowthinprosperityoverthelasttwodecades,withthemedianincomeincreasingby

46.18%from1990to2013.ThepercapitaincreaseinVKTinSaskatchewanexceededotherprovincesby

alargemagnitude,increasingalmost70%in23years.Aswell,provinceswiththehighestgrowthinper

capitaVKT,suchasNewfoundland&Labrador(55.06%),Manitoba(27.42%),andPrinceEdwardIsland

(10.83%),allhadstronggrowthinincome(26.26%,20.56%,and20.09%,respectively).

Itisimportanttonotethatthetimeframeforthedecompositionanalysesendedimmediately

after the 2008 global recession,whichwould have certainly affected vehicle use, particularly in the

United States whose economy was hardest hit. Unfortunately, neither country’s travel surveys go

beyond 2009, so vehicle use was unable to be analyzed fully as the economy recovered. This is

particularlynotablegiventhatGDPhashistoricallyplayedalargeroleinoveralltrendsinvehicleuse(Le

Vineetal.2009).Infact,therehasbeenaslightincreaseinpercapitaVKTintheU.S.inthelasttwo

years,potentiallysuggestingareboundinVKT.Ofcourse,growthinVKT,whetherornotshort-lived,


53

couldbeduetonumerousotherfactorsaswell,suchasgasprices.Nonetheless,theseareimportant

trendstocontinuemonitoring.

OtherExplanatoryVariables

Finally,changesinvehicleusecouldbetheresultoffactorsthataremuchmorechallengingto

model. This could include shifts in youth culture and preference, aswell as local policies. In recent

decades,many jurisdictions,particularly cities,have implementedpolicies toencouragemulti-modal

behaviour. For instance, some roadways are now being shared, with designated lanes for buses or

bicycles,ratherthanbeingreservedsolelyforcartravel.Manycitiesareimplementingpoliciesdesigned

to prevent single-person vehicle trips, such as car pooling stations and public transit park-and-go

facilities.Futureresearchshouldassesshowoverallvehicletrendsarebeingaffectedbytheconvergence

ofmultiplepolicies,infrastructuredevelopments,andland-useplanningstrategies.

CaveatsandDataLimitations Todate,therehasbeenverylittleresearchconductedonCanadianvehicleuse,especiallyusing

quantitativemethods.However,itisimportantthatweunderstandhowvehicleusemayormaynotbe

changing inCanada,andwhat thismeans for theassociatedexternalities, including trafficaccidents,

urbancongestion,airpollution,andgreenhousegasemissions.

Unfortunately,theunreliabilityandpoorqualityofCanadiandatahasmadeitverychallenging

toidentifylongtermtrendsanddrawclearconclusions.Althoughdatafornationalorprovincialtotal

VKTdoesexist,datawassparseforagerelateddriving,andnon-existentforurbanandruraldriving.

Muchof the issuesurroundstravelsurveys, thedataofwhich is fragmentedandpoor.For instance,

withinthelast25yearstherehavebeenthreesurveysonhouseholdvehicleuseinCanada,onefrom

1994to1996,onecurrentlyongoingsince2013,andtheoneused inthisstudy, from2000to2009.


54

Althoughtheyasksimilarquestionsandhavesimilarobjectives,thedatahasbeenpresentedinsucha

waythatcomparisonsbetweensurveysisnotpossible.Duetothisincompatibility,theanalysisinCanada

was restricted toperiod from2000 to2009. This time frame is too short todrawclear conclusions,

especiallysinceitincludedalargeatypicalevent,the2008globalrecession.Thisisalsothecasefornon-

surveydata,includingtotalVKTwhichisonlyavailablefrom1990,makingitimpossibletocapturelong-

termtrends.WhenexaminingtrendsintheU.S.,onecanseehowimportantitistoalsoincludeprevious

phasesofgrowth,beforetheperiodofinterest.

Somedata,suchasdriverlicenses,isonlyprovidedbyprovincialministries,ratherthanfroma

central federaldatabase.Asa result, dataon licensing rateswasdifficult to trackdown,andnotall

provincescouldprovidedataforeveryyear,ordataatall.Subsequently,wewereforcedtoimputethe

numberoflicensesatthenationallevel,reducingthestrengthofouranalyses.Dataoncarownershipis

alsoprovidedbyprovinces,butduetothedifficultyintrackingdownthedata,carownershipcouldnot

beincludedintheanalysis.

Anotherissuewasthatthedatadidnotallowforprovincialcomparisonsofvehicleuseinterms

ofagegroups.Asmentionedabove,trendsdiffersubstantiallybetweenprovinces,andassessingthese

trendsonaprovince-by-provincebasiswouldhavebeenextremelybeneficial.

ThedeficiencyofCanadiandataisparticularlyevidentwhencomparingvehicleusetotheUnited

States.TheAmericantravelsurveysdatefurtherback,andthetwoAmericansurveytypesaredesigned

tobecomparable.Furthermore,trendsamongagegroups,locationandsettlementtypes,aswellasfor

differentmodesoftransportationandotherimportantvariables,areeasilymeasurable.Incomparison,

itisverydifficulttomakeconclusionsaboutCanadawithsuchpoorqualitydataandwithoutbeingable

tocapturelong-termtrendsinvehicleuse.


55

Finally,onemusttakecautioninthecomparisonoftrendsbetweentwocountries.Specifically,

CanadaandtheUnitedStateshavedifferentdatasourcesandcollectionmethods.Forone,thetravel

surveysareverydifferent;theAmericanversionismuchmoresophisticated,usesamuchlargersample

size,andcouldpossiblyusedifferentstatisticalmethods.Aswell,otherformsofdatacouldbedifferent,

intermsofcollectionmethodsorstatisticalapproaches,suchasvehiclekilometrestravelled.Asaresult,

comparisons invehicleusebetweencountriesshouldbetakenwithagrainofsalt. It shouldalsobe

notedthatthisresearchispurelyspeculative;theaboveanalysesincludenoexperimentationandthus

causeandeffectcannotbeascertained.Nonetheless,asdiscussed,wecanbereasonablyconfidentwith

theconclusions,basedonmultiplesetsofanalyses.


56

CONCLUSION&IMPLICATIONS ItisunclearwhyCanadianvehicleusediffersfromothercountries,showinglessgrowthanda

moremutedplateauinpercapitadriving.However,contributingfactorstovehicleuseseemtobesimilar

betweenCanadaandtheUnitedStates,withyoungadultsdrivinglessandseniorsdrivingmoreeach

year.

Ithasbeenestablishedthatyoungadultsaredrivingless;thequestionremainswhetherthisis

duetoeconomicfactorsorothersocialorculturalshifts.Ifeconomicfactorsareplayingalargerrole,

thenwemayseeasurgeinVKTasCanadianMillennialsreachtheir30s,entertheworkforce,andearn

more.However,ifthehabitsofyoungadultsaresetinstonenow,thechangemaybecomemorecultural,

andthuswemaynotseemillennialvehicleuserebound,potentiallyimpactingCanadianvehicleuseas

awholedramatically.

Today,populationgrowthand incomearebothhavinganotablepositive influenceondriving

trendsinCanada.Inlightoftheexpectationthatbothofthesefactorswillcontinueincreasinginthe

comingdecades,decision-makersoughttoconsiderpoliciesthatwill limitvehicleuse.An interesting

factortoconsideristhearrivalofnewimmigrants,nowaccountingfortwothirdsofpopulationgrowth

in Canada (Statistics Canada 2015), whomay have different cultural relationships with the car. For

instance,ifthe“American,orCanadian,Dream”ofowningahousewithmultiplecarsinthesuburbsis

notlongertrueformanyestablishedCanadians,thismaystillbeveryimportanttonewimmigrants.

Gasolineisaninternationallytradedcommodity,andgaspricesaresetbytheglobalmarket.For

thisreason,itisimpossibletoknowhowgaspriceswillchangeinthecomingdecades.However,based

ontheresultsfromnationaltrends,aswellasinBritishColumbia,recentincreasesingaspriceshave

likelypreventedgrowthinpercapitaVKT.Giventhelargeexternalitiesassociatedwithdriving,suchas


57

greenhousegasemissions,trafficaccidents,urbancongestion,andairpollution,jurisdictionsinCanada

andabroadmaywanttoconsidercarbonorgasolinetaxestolimitgrowthinvehicleuse.Contrarily,if

gaspricesfallinthecomingdecades,vehicleusecouldgrow,aswilltheassociatedexternalcosts.

Transportation planners cannot know the future, and trends require ongoing examination.

Overall, income and population growth are responsible for pushing vehicle use upwards, while

behaviouralshifts,inpartduetogasprices,areresponsibleforpushingvehicleusedownwards.Other

culturalorsocialaspectsmayalsobeatplay.Mostimportantly,CanadiansandAmericanshavebeen

drivinglessonaverageinthelastdecadeorso,withyoungadultsleadingthetrend.Regardlessofthe

futuretrajectoryofvehicleuse,policiestocurbtheexternalcostsofdrivingmustbeconsidered.


58

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APPENDICES Appendix 1: Non-linearity of median income Appendix 2: Outliers

-0.2 0.0 0.2 0.4

-0.4

-0.2

0.0

0.2

log(gasprice)

Component+Residual(log(pcvkt))

10.5 10.7 10.9 11.1

-0.3

-0.1

0.1

0.3

log(medianincome)


40 50 60 70 80

-0.3

-0.1

0.1

percent.urban


9 10 11 12

-0.3

-0.1

0.1

percent1824


10 12 14 16 18

-0.3

-0.1

0.1

0.3

percent65pl


1990 1997 2004 2011

-0.4

0.0

0.2

0.4

factor(year)


Alberta Nova Scotia

-0.3

-0.1

0.1

factor(prov)


Component + Residual Plots

*

********

*

*********

*

*********

*

********************************************************************************

*********************************************************************

**********

*

*********

*

*

********

*

*

*

**

*

*****

*

**

*

*

****

*

*

*

*

******

*

0 50 100 150 200

0.00

0.02

0.04

0.06

0.08

0.10

Influential Obs by Cooks Distance

Index

cooksd

1

10

20

30190

200

201

210

211

215

221

222223

225

231

233240


64

Appendix 3. Other assumptions of the linear regression model.

8.9 9.0 9.1 9.2 9.3 9.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

Fitted values

Residuals

lm(log(pcvkt) ~ log(gasprice) + log(medianincome) + (percent.urban) + (perc ...

Residuals vs Fitted

22121110

-3 -2 -1 0 1 2 3

-4-2

02

4

Theoretical Quantiles

Sta

ndar

dize

d re

sidu

als


Normal Q-Q

22121110


65

8.9 9.0 9.1 9.2 9.3 9.4

0.0

0.5

1.0

1.5

2.0

Fitted values

Standardized residuals


Scale-Location

22121110

0.00 0.05 0.10 0.15 0.20 0.25

-4-2

02

4

Leverage

Sta

ndar

dize

d re

sidu

als


Cook's distance

Residuals vs Leverage

22120

211

have we reached peak driving?: a 25-year decomposition of ... · class, the proportion of cars on...

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