外文翻譯-城市的流動(dòng)性和城市形態(tài)：不同模式的城市擴(kuò)張產(chǎn)生的社會(huì)和環(huán)境成本

畢業(yè)設(shè)計(jì)外文資料翻譯題目城市流動(dòng)性和城市形態(tài)：不同模式的城市擴(kuò)張產(chǎn)生的社會(huì)和環(huán)境成本學(xué)院土木建筑學(xué)院專(zhuān)業(yè)建筑學(xué)班級(jí)學(xué)生學(xué)號(hào)指導(dǎo)教師二〇一一年三月二十八日EcologicalEconomics40(2002)199–216Urbanmobilityandurbanform:thesocialandenvironmentalcostsofdifferentpatternsofurbanexpansionRobertoCamagni,MariaCristinaGibelli,PaoloRigamontiAbstract：Thequestionoftheenvironmentalorsocialcostsofurbanformisincreasinglyattractingattentioninspatialpolicy,butscienti?cdebateinthis?eldisoftenmarredbyprejudicesandabstractvisions;empiricalanalysesareveryrare.Thepresentstudyaimsatestablishing,inthemetropolitanareaofMilan,whetherdifferentpatternsofurbanexpansioncouldbeassociatedwithspeci?cenvironmentalcosts—inparticular,forlandconsumptionandmobilitygeneration.Differenttypologiesofurbanexpansionwerede?ned,andanimpactindexweightingdifferentlyjourney-to-worktripswithreferencetomodeandtimelengthwasbuiltatthemunicipalitylevel.Thestatisticalanalysiscon?rmedtheexpected‘‘wasteful’’characterofsprawlingdevelopmentpatternsintermsoflandconsumption,thoughsuggestingthatrecenturbandevelopmentisbecomingrelatively‘virtuous’withrespecttothepast.Withreferencetothemobilitygenerated,higherenvironmentalimpactswereprovedtobeassociatedwithlowdensities,sprawlingdevelopment,morerecenturbanisationprocessesandresidentialspecialisationofthesinglemunicipalities.Publictransportseemstobestronglyin?uenced,bothintermsofef?ciencyandcompetitiveness,bythestructuralorganisationofanurbanarea:themoredispersedandlessstructuredthedevelopment,theloweritslevelofef?ciencyandcompetitivenessandconsequentlyitsshareofthemobilitymarket.Onthecontrary,triptimesforprivatetransportappeartobecorrelatednotsomuchtourbandimensionordensityastothepresenceofrecenthousingdevelopment,indicatingtheemergenceofnewmodelsoflifestyleandmobilitywhichareverydifferentfromthoseofthepast.?2002ElsevierScienceB.V.Allrightsreserved.Keywords:Urbanexpansion;Urbanform;Urbansustainability;Publictransport1.IntroductionTogetherwithtechnologiesandconsumptionstyles,theformofsettlementsandthewayhumanactivitiesareorganisedingeographicalspacerepresentcrucialresearch?elds—andsourcesofpreoccupation—asfarasecologicalequilibriaareconcerned(Camagnietal.,1998).Infact,inprinciple,theresource-ef?ciencyofdifferentsettlementpatternsissubjecttowidevariationswithreference,atleast,totwoscarcenaturalresources:landresources(forresidentialuses)andenergyresources(formobilityuses).Landconsumptiondependsdirectlyontherelativecompactnessofhumansettlementsandonresidentialdensity;energyconsumption,ontheotherhand,dependsindirectlyonthesamevariables,viatheirlinkagewithmobilitypatterns:triplengthandmodalchoicebetweenprivateandpublicmeans.Thestudyisdividedintotwomainparts.Inthe?rstpartweanalysethetypicalfeaturesofcurrenturbandevelopmentandlookattheresultsofsomerecentinternationalempiricalanalysesonthecomparativecostsofdifferenttypologiesofurbandevelopment(Section2);inthesecondpartwepresentthemain?ndingsofourempiricalanalysescarriedoutintheprovinceofMilan:wede?neanumberofarchetypalformsofurbandevelopment(Section3.1),measuretheassociatedconsumptionofland(Section3.2)andthencarryoutadetailedanalysisofthemobilitygeneratedanditsenvironmentalcosts(Section3.3).2.Developmentattheurbanfringe:dynamics,interpretationsandempiricalanalysis2.1.Emergingurbanformanditsrele
anceforsustainablede
elopementInEurope,theareassurroundingmostlargecitieshavebeenradicallytransformedoverthelast20years.Notonlyhastherebeenanincreaseingamountofbuiltdevelopment,butthishasspreadextensivelyinformswhichareverydifferentfromthosecharacterisingtraditionalsuburbanisation,i.e.expansionthatoccurredaroundadenseurbannucleus,prevalentlythroughextensionand/orrelativelycompactdevelopment.Manyurbanareas,althoughdemographicallystatic,oratthemostshowingweaksignsofpopulationgrowth,havespreadoutand‘diluted’overspaceinaformofdevelopmentwhosefeatureshavebeenveryeffectivelydescribedwiththetermsprawl:lowdensitydevelopment,extendingtotheextremeedgeofthemetropolitanregionandlocatedinarandom,‘leapfrog’fashion,segregatedinspecialisedmono-functionallanduses,andlargelydependentonthecar(Mayetal.,1998;OECD,2000).Therearemanycloselyinterrelatedreasonsforthesuccessofthe‘diffusedmetropolis’.Asfarasresidentiallocationisconcerned,themainreasonsappeartobe:thedeclineinenvironmentalqualityofthedenselybuiltcitycentre,duetotraf?ccongestion,pollution,degradationofpublicspacesandreductionofsafety;changeinlifestyles,dueinparttotheincreaseinincomes,infavourofmorespaciousdecentralisedhousing;thereplacementofresidentiallanduseinthecitycentrebytertiaryactivities;thefactthathousingimprovementinthecitycentrecostsmorethannewconstructionoutsidethecity;andthehousingsupplystrategiesofrealestateagents,which?ndlessresistanceinthemorespaciousout-of-townareas.Thosewhotakethesecondapproachmaintainthatitiscrucialtointervene,throughtheadoptionofsectoralandspatialplanningpolicies,tocontainurbansprawl.Theyconsiderthecurrent,andaboveall,theprobablefuturecostsundesirable,maintainingthatthesearelikelytogrowexponentiallyintheabsenceofcorrectivemeasures.Theemergenceofthethemeofurbansustainabilityisanelementwhich,inrecentyears,hasstrengthenedthissecondview,stimulatingavarietyofre?ectionsandalsooperativeindications.The?rstapproachiswellrepresentedintheEuropeancontextbythe‘theoreticians’ofthevillee′mergente(ChalasandDubois-Taine,1997),convincedopponentsofanylargescaleplanningaimedatcontrollingurbansprawlorrestrictingthemobilityandlocationpreferencesofindividualsoreconomicactivities.Theyarguethatitisimpossible(duetothegrowingcomplexityofthespatialinteractionspermittedbycarmobility),pointless(asnewtechnologieswillallowincreasingfreedomoflocation),butaboveallsociallyundesirablesincethe‘villea`lacarte’,orthe‘villeauxchoix’willofferanincreasingfreedomforpeopletodesigntheirown‘life-spaces’andinterpersonalrelations,aprocessinwhichitisnotacceptabletointerfere.EvenmoreradicalistheviewoftheNorthAmericanfree-marketeers,whoclaimthattheproblemscausedbyextensivesuburbanisationareoverestimated,emphasisingthatthenewinformationtechnologiesaresettoacceleratethedispersionofpopulationandjobsuntilphysicalproximitywillbecomeirrelevant.Theyargue(GordonandRichardson,1997):·thatonlyunacceptablepoliciesof‘commandandcontrol’couldconsiderinterferingwiththeevidentindividualpreferenceforlowdensityhousing;·thattherelationshipbetweenurbandensi?cationandreductionofenergyconsumptionisnotscienti?callyproved;·thatspontaneousprocessesofself-correctionarepossibleintheshorttomediumtermtoreducethehome-to-workdistance,asshownbytheedge-cityphenomenon;·thattheef?ciencyofmorecompactsuburbandevelopmenthasyettobedemonstrated,bothintermsofcostsandsocialre-equilibrium;·and?nallythattop-down,largescaleplanningwouldrisktakingawayresponsibilityfromlocalauthoritiesinaperiodofglobalisationandgrowingcompetitionbetweencitiesinwhichanyplanningerrorisimmediatelypunishedbythemarket.Thismetaphorhasbeenputinquestionbysomescholarsastoobroad,genericandideological(Breheny,1992;Banister,1992;Jenksetal.,1996).Inparticular,theurbanscaletowhichitshouldapplyremainsuncertainand,beyondcertainlevelsofdensityandsize,itcouldproduce‘towncramming’andscalediseconomieswhichareamongthemaincausesofpresentsuburbanisationtendencies(Elkinetal.,1991;Fouchier,1998).Asuf?cientagreementexists,though,aboutthedesirabilityofapolycentricurbanstructure,organisedonsmallandmedium-sized,compactcentres,wellconnectedthroughanef?cientnetworkofpublictransport(BrehenyandRookwood,1993;Blowers,1993;Breheny,1996;HallandLandry,1997),wesometimescalleda‘wiselycompact’urbanstructure(CamagniandGibelli,1996).2.2.DemandformobilityanditsrelationshipwiththeformofcityexpansionThedemandformobility,andinparticularthegrowingdependenceonprivatevehiclesforintra-metropolitantrips,iscurrentlyacrucialcomponentinthedebateonsustainableurbandevelopment,giventheeconomic,socialandenvironmentalimpactforwhichitisresponsible.Adiffusedpatternofurbandevelopment,almostbyde?nition,cannotbeadequatelyservedbythepublictransportinfrastructuresincethedemanddensityislow,thescatteringofthedemandovertheterritoryishighandthedispersionofdestinationsisalsogrowingbecauseofthesuburbanisationofjobs.Thisisthereasonwhysomanyanalysesofthesocial,economicandenvironmentalcostsofurbanexpansionhaveconcentratedonthepervasivepresenceoftheautomobile:atechnologycapableof‘bringingplacesnearer’byprovidingaccesstotheincreasinglydispersedandspecialisedurbanfunctions(Cervero,1998;NewmanandKenworthy,1999).ThesubjecthasalreadybeenwidelyinvestigatedinNorthAmerica,andisnowbecomingthefocusofdebateinEurope,too,giventheemergenceofthephenomenonofsprawlingurbandevelopmentanditsincompatibilitywiththeobjectivesofsustainability.Onequestionposedbymanyresearchers,andalsoexaminedinthepresentinvestigation,iswhetheritispossibletodemonstrateasigni?cantrelationshipbetweenmobilityconsumptionandthemorphologyofurbandevelopment.Inthisconnection,itisinterestingthatanempiricalanalysisundertakenrecentlyintheParismetropolitanareashowsadirectrelationshipbetweentherateofcarownershipanddistanceoftheareaofresidencefromthecentre,andalsoanindirectrelationshipbetweenthedemographicdensityoftheareaofresidenceandvariablessuchastherateofcarownership,thedistancetravelledeachdayandthepercapitaconsumptionofpetrol(Fouchier,1998).2.3.Thecostsofsprawlininternationalsurveys:landconsumptionandpubliccostsWenowcometothecentralthemeofourresearchprogrammeonthecommunitycostsofsuburbandevelopment,inordertounderlineimmediatelyadif?cultythatouranalysisshareswithotherinvestigationsattheinternationallevel.Althoughgoodevidencehasalreadybeenprovidedoftheeconomic,socialandenvironmentalcosts,?ndingsrelatingtothepubliccostsofsprawlaremodest,duemainlytotheobjectivedif?cultiesof?ndingsigni?cantandreliableperformanceindicators.Thespeci?cresultsavailablerelatetostudiescarriedoutpredominantlyinNorthAmericaandthereforerefertoratherdifferentsuburbanisationpatternsandaverydifferentinstitutional/administrativecontext.Nevertheless,itissigni?cantthatthe?ndingsrevealasigni?cantcorrelationbetweendifferentformsofurbangrowthandpubliccosts.Pioneerresearchwascarriedoutinthis?eldin1974bytheRealEstateResearchCorporationoftheUSGovernmentinordertoestimatetheeconomicandenvironmentalcostsofdifferenttypesofurbandevelopmentanddifferentformsofgrowthontheurbanfringe.Theempiricalanalysesconsiderthepubliccostsrelatingtotheconstructionandmaintenanceofschools,housing,greenspace,roadsandshoppingcentres,andestimatethecoststothecommunityintermsofthenegativeenvironmentaleffects(landconsumption,air,waterandnoisepollution)andsocialeffects(carjourneytime,accidents,psychologicalandsocialcosts).Themainresultofthisresearchwastheidenti?cationofurbandensityasthefundamentalvariableoftheoverallcostssustainedbythecommunity(RealEstateResearchCorporation,1974),thoughtheseconclusionsdidnotgounchallenged:see,amongothers,Altshuler(1977)andWindsor(1979).Thisresearch,whichmadeuseofstatisticalanalyses,casestudiesandsurveysoflocalauthorities,examines?vetypesofdevelopment:thedensi?cationofthecitythroughre-useandin?ll,urbanextension,keyvillageextension,multiplevillageextension,andnewsettlement.Theadvantagesanddisadvantagesofeachtypewereassessedintermsoftheeconomic,socialandenvironmentalcosts,bothpublicandprivate,withtheaimofformulatingrecommendationsandsuggestionsforactionaimedatvariousadministrativelevelswithresponsibilityfortownandcountryplanning.Theauthorsthemselvesdeclarethe?ndingstobelargelyinconclusiveastothepreferablemodel.3.Socialcostsofdifferenttypologiesofurbanexpansion:landconsumptionandmobilitypatterns3.1.TypologiesofurbanexpansionFollowingthegeneralre?ectionsoutlinedabove,thepurposeofourempiricalanalysis,carriedoutintheprovinceofMilano,wastoidentifythecharacteristicsofurbandevelopmentandthesocialcostsoftheurbanexpansionwhichoccurredduringtheten-yearperiod1981–91.ThevariablesexaminedincludetheconsumptionoflandforhousingdevelopmentandUsingasastartingpointthemapsdrawnupbyCentroStudiPIMonlandconsumptionintheMilanoareain1991,thepatternsofresidentialdevelopmentovertheperiod1981–91ineachofthe186communeswithintheprovincewereanalysedusingadescriptive/intuitiveapproach.Atthemacrolevel,itwaspossibletodistinguish?vetypesofurbanexpansion:·in?lling(T1),·extension(T2),·lineardevelopment(T3),·sprawl(T4),and·large-scaleprojects(T5).TypeT1ischaracterisedbysituationsinwhichthebuildinggrowthoccursthroughthein?llingoffreespacesremainingwithintheexistingurbanarea;T2occursintheimmediatelyadjacenturbanfringe;T3isdevelopmentwhichfollowsthemainaxesofthemetropolitantransportinfrastructure;T4characterisesthenewscattereddevelopmentlots;T5concernsnewlotsofconsiderablesizeandindependentoftheexistingbuiltupurbanarea.Allthecombinationsamongthesetypeswerethenidenti?edand,?nally,byeliminatingandre-assigningtheleastsigni?cantcombinations,aselectionof10prevalenttypologieswasarrivedat.Thesetypologieswereusedinthestatisticalanalysisonlandconsumption;inthesubsequenteconometricanalysistheywerereducedtofourmaintypologiesandusedasindependentdummyvariables,togetherwithothervariablesreferringtosettlementstructure,intheinterpretationoftheenvironmentalimpactofmobility.Beforegoinganyfurther,weshouldspecifyanimportantcaveat.Giventhelevelofsubjectivityinherentintheattributionofthevariouscommunestothedifferentcategories,theresultswhichwenowanalysemustbetakenasapreliminaryapproximation.3.2.Asfarastheanalysisoflandconsumptionisconcerned,the?rstsurveywecarriedoutcomparesthelandareadevelopedforresidentialandserviceusebetween1981and1991ineachcommunetothenumberofdwellings.Thisindicatorwaspreferredtothepercapitaconsumptionoflandbecausethelattermayincreaseincaseswherethepopulationofacommunedeclines,givingafalseindication.Threemaincategoriesemerged(Fig.1):·therelatively‘thrifty’types,whereconsumptionwasbelow450m2perdwelling,whichcorrespondedasexpectedtothecategories‘purein?lling’and‘largescaleprojects’;·therelatively‘land-greedy’types,whichbelonged,againasexpected,tothecategories‘puresprawl’,‘lineardevelopment-sprawl’,and‘extension-sprawl’,whereconsumptionwasabove600m2perdwelling,plus‘extension-linear’developmentwith
550m2perdwelling;·anintermediategroup,whichincludedthecategories:in?lling-extension,in?lling-sprawl,pureextensionandpurelineardevelopment,withconsumptionaround500m2perdwelling.Ifweobservetheratiobetweenthenewbuiltupareaandnewdwellingsintime(1981vs.1991),anunexpectedlypositivetrendemerges.Infact,foralltypesofdevelopment(exceptin?lling),theconsumptionoflandperdwellingisslightlydecliningintime.Thissuggeststhatnewurbandevelopmentoverallisrelativelyland-sparingcomparedwiththepast.3.3.Thedemandformobilityanditssocialcosts3.3.1.MethodologyItemergesclearlyfromtheliteraturethatthedemandformobilityisanimportantcomponentoftheenvironmentalimpactofurbandevelopment,asillustratedinSection2.Forthisreason,inthepresentstudyitwasdecidedtoestablishwhetheritispossibletoidentifysigni?cantdifferencesofbehaviourwithinthestudyareaasfarasmobilitywasconcernedand,ifso,toascertainwhetherthereisanysigni?cantcorrelationbetweenthesedifferencesandvariablesdescribingtheformofdevelopment.Theintentionistoprovideabasisfororientingplanningpolicies.Theworkinghypothesisisthatwithinarelativelyhomogeneousarea(intermsofincomelevelandgeneralsocio-economicconditions),suchastheprovinceofMilano,thelocaldifferencesinthemobilitypatterns(timeandmode)can,atleasttoacertainextent,beattributedtotheforminwhichurbangrowthhasoccurred.Mobilitythereforehastheroleofdependentvariable,whiletheformofdevelopmentanditsdynamicsrepresenttheindependentvariables.Fourtypesofindependentvariableswereadopted(seeAppendixAforstatisticaldetailsandde?nitionofvariables):·geographicalvariables:distancefromMilan;·socio-economicvariables:populationdensity,sizeanddynamics,ageofbuildings,ratioofjobstoresidentpopulation(Emp/Res);·morphology:i.e.thetypologiesofurbandevelopmentpreviouslydescribed,reducedtofourclasses:in?lling-extension;extension-linear;sprawl;large-scaleprojects(seeAppendixA);·accessibilityandtransportef?ciency:competitivenessofpublictransport,shareofpublictransport,averagetriptimeforpublictransporttrips(Publictime)andprivatetransporttrips(Privatetime).3.3.2.FactorsdeterminingtheintensityofthemobilityimpactThespatialdistributionoftheindicesofimpactintensitywasexaminedusinganeconometricanalysistoascertainwhethertherewasasigni?cantcorrelationwithanyoftheselectedindependentvariablesdescribingthecharacteristicsoftheurbanform..ItisimportanttonoteherethatusingthesetechniquesinsteadofOLSdidnotinvolve,forourmodelandforouraims,bigdifferencesintheresults(Table2).Therefore,itispossibletosaythattheinferencebasedonthesimplerOLSestimators,whilenotcompletelyaccurate(aboveallasfarasthestandarddeviationoftheestimatorsisconcerned),isnotmisleading.Forthisreason,intheremainderofthepaperonlyOLSestimatorswillbedisplayed,eventhoughweacknowledgethatmoreef?cientestimatorscouldbefound,inparticularifwewereinterestedintestinghypothesesaboutthevalueoftheparameters.Theoutcomeissummarisedbrie?yasfollows:·asigni?cantinverserelationshipwasfoundbetweentheindexmeasuringthemobilityimpactandnetpopulationdensity(densityofthebuiltuparea),inlinewiththeexpectationsexpressedintheinternationalliterature.Togetherwiththesizeoftheurbanareasintermsofabsolutepopulation,densityappearstohavemainlyanindirecteffectonthemobilityimpact,throughitsin?uenceontheaveragetriptimeofpublictransportandhenceonthemodalsplitofcommutertripsinfavourofpublictransport;·asigni?cantrelationshipalsoexistswiththevariablesrepresentingdemographicgrowthrateandtheaverageageofhousing.Inbothcases,theimpactindexincreasedwiththedynamismofthecommunesconcerned:inotherwords,highvalueswereassociatedwithcommuneswitharapidgrowthofpopulationoverthetenyearperiod1981–1991andalsothosewithnewerhousing,i.e.areasofrecentexpansion;·thecoef?cientrelatingtothedistancefromthecentreofMilanissmallintermsofabsolutevalues(0.006pointsperkm),butissigni?cantlylessthanzero,indicatingthegreaterautonomyofthetownsinthemostexternalpartsoftheprovinceandaspatialstructureofsettlementssimilartothatofaself-contained‘industrialdistrict’;·followingthesubdivisionintogroupsproposedinthepreviousparagraph,threedummyvariableswereintroducedtoallowforinterceptshift.Theanalysisoftherelativecoef?cientsmakesitpossibletoestablishthefollowingranking(inincreasingorderofimpact):in?llextension,extension-lineardevelopment,sprawl,large-scaleprojects;·?nally,ananalysiswasmadeoftheroleoftheemployment/residentsratio,avariabletowhichtheliteratureattributesconsiderableimportanceinconnectionwithmobilitydemand.Thisrelationshipcanbeconsideredanindicatoroftheleveloffunctionaldiversi?cation–integration–segregation,the‘functionalmix’ofeachcommune.Asigni?cantandnegativerelationshipemergedinthemultipleregressionanalysis,indicatingthatthemobilityimpactwashigherwhentheproportionofemploymentwaslower,i.e.inareasofspecializedresidentialnature.3.3.3.Componentsofthemobilityimpact:modalchoiceandtriptimeAswehaveseeninSection3.1andTable1,themobilityimpactindexistheresultoftwocomponents:transportmodeandtriptime.Thesetwocomponentsdeterminetwodistinct‘logicalchains’throughwhichitispossibletohypothesiseacausalrelationshipbetweenthephysicalstructureofurbandevelopmentandthesocialcostsrepresentedbythemobilityimpact(Fig.2).Ontheonehand,wehave:·settlementsofrelativelycompactstructure→greatercompetitivenessofpublictransport(intermsofjourneytoworktime)→greateruseofpublictransport→lowermobilityimpact(lefthandlogicalchaininFig.2);ontheother:·settlementsofrelativelycompactstructure→greateref?ciencyofbothpublicandprivatetransport→lowercommutingtime→lowermobilityimpact(right-handlogicalchaininFig.2).Beforemovingtowardstheeconometricanalysis,itseemsnecessarytomakeamethodologicalpoint.Acausalinterpretationofthemodelspresentedinthefollowingcannotbederivedfromastatisticalestimationprocess,butcanbemaintainedonlyonthebasisofaprioritheoriesorknowledgeregardingthephenomenonunderconsideration.Itthenfollowsthatalltheestimatesreportedbelowcangiveonlyanideaofthestrengthofthecausalconnectionsbetweentheinvolvedvariablesandnotoftheirdirection.4.ConclusionsThewidedispersionofmetropolitanpopulationandthespreadofsettlementpatternswithahighconsumptionofscarceornon-renewableresources(especiallylandandenergy)arerelativelyrecentphenomenainEurope.Theyhavetriggereddebate,innewformsandwithnewpolicyoptions,ofanissuealreadywellrootedinthetownplanningtradition,thatofurbancontainment.Neologismssuchas‘villee′clate′e′’,‘villee′mergente’,‘citta`diffusa’,‘ubiquitouscity’andsoon,haveallbeenusedtoexpressthisrenewedinterest,thoughrepresentingdifferentanalyticalapproachesandinterpretations.Itwasinthiscontextthatthepresentempiricalanalysiswasdeveloped,withtheaimofestablishing,inthemetropolitanareaofMilan,whetherdifferentpatternsofurbanexpansioncouldbeassociatedwithdifferentsocialandenvironmentalcosts—inparticular,forlandconsumption,and,aboveall,mobilitygeneration.Asfaraslandconsumptionisconcerned,threemaincategoriesemerged:acategoryofrelatively‘virtuous’patterns(purein?llandlarge-scaleprojects),anintermediatecategory(in?ll-extension,in?ll-sprawl,pureextensionandpurelineardevelopment),and?nallya‘wasteful’categoryofdevelopment(encompassingpuresprawl,lineardevelopment-sprawl,extension-sprawl,andextension-lineardevelopment).Thiswasinlinewithexpectations.Ananalysisofthedynamicaspects,however,revealedanunexpectedtrend:overtheperiod1981–91theconsumptionoflandperdwellingdecreasedslightlyforalldevelopmenttypes,suggestingthatrecenturbandevelopmentisbecomingrelatively‘virtuous’withrespecttothepast.Secondly,withreferencetothequestionofmobility,anindexofenvironmentalimpactofthemobilitygeneratedineachmunicipalitywasbuilt,weightingdifferentlythedifferentmodesandtimelengths.Urbandensity,demographicgrowthrates,ageofthebuildingstockandfunctionalmix(economic-residentialbalance)wereprovedtobestatisticallysigni?cantinexplainingmobilityimpact.Higherimpactsareassociatedwithdiffused,sprawlingdevelopment,morerecenturbanisationprocessesandresidentialspecialisationofthesinglemunicipalities.Publictransportseemstobestronglyin?uenced,bothintermsofef?ciencyandcompetitiveness,bythestructuralorganisationofanurbanarea:themoredispersedandlessstructuredthedevelopment,theloweritslevelofef?ciencyandcompetitivenessand,consequently,itsshareofthemobilitymarket.Onthecontrary,triptimesforprivatetransportappeartobecorrelatednotsomuchtourbandimensionordensityastothepresenceofrecenthousingdevelopment,indicatingtheemergenceofnewmodelsoflifestyleandmobilitywhichareverydifferentfromthoseofthepast.Intermsofmobility,theleastenvironmentallyacceptablesituationsarerepresentedbytwooppositetypesofdevelopment(sprawland‘large-scaleprojects’),whichshowaverydifferentbehaviourwithrespecttothemodalsplit.Sprawlisassociatedwiththelowestshareofpublictransport,whilelargeprojectshavethelowestshareoftripsmadeonfoot.Inconclusion,ourresultscon?rmthefarsightednessofthestrategicguidancesandinnovationsattheurbandesignlevelthataimtowardsa‘wiselycompact’andpolycentricpatternofurbandevelopment.ReferencesAltshuler,A.,1977.ReviewoftheCostsofSprawl,JAIP43,April,207–209.Blowers,A.(Ed.),1993.PlanningforaSustainableEnvironment.AReportbytheTCPA.Earthscan