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Improvingbalticseaservices–Aquantitativeplanningapproach
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transporttimeandtheresultsontherankingorderwerenotasclear.Thiscan
bepartlyexplainedbythestructureofthestudies,whichallexaminedthecostand
transporttimefactorbutlaiddifferentemphasisontheexaminationofotherfactors.
Bühlercalculateddemand-elasticity-factorsfordifferentdecisionvariables.
Thesefactorsareinsofarinteresting,astheyallowaclearquantitativeassessment.
Theseelasticityfactorsshallalsobeusedinthemodeldescribedinthepaper
athand.AsBühlerfoundtransportcosts,timeofdeliveryandtransporttimetobe
mostimportant,themodelshallbebasedonthesefactors.Servicefrequencyshall
beincludedasadeterminingfactorfortransporttime(asaferry-sevice-frequency
leadstowaitingtimesataport).Deliverytimeshallalsobemodeledaspart
oftotaltransporttime,asexplainedbelow.
Figure2showsthegenerallayoutofthemodel.Cost-andtimetable-submodelsex-
istthatprovidecostandtimedata.Thetimetablemodelsprovideutilizationdata,that
arethenusedinthecostmodels(comparefollowingsections).Costsarecalculatedper
vehicleandtrip,whilethetimetablemodelsprovidedataaboutthetotaltransporttime
ofaloadunit(e.g.atrailerorswapbody)andthearrivaltimeatthedestination.
Inthepaperathanda„transportchain”usuallyconsistsofa(roadtransport)tour
ofatruckfromitsdeparturepointtoaport,atransshipmentprocessontoaRoRo-ferry,
theRoRo-ferrytransportacrossthesea,atransshipmentprocessfromtheRoRo-ferry
atthedestinationportanda(roadtransport)tourofthetrucktoitsdestination.
Differencesbetweentransportchainsarecalculatedfortransport-costs,
transport-timesandarrival-timesandthedeterminingfactorsoftheferryservice
(price,transportcosts,covereddistance,positionsofportsintheroadnetwork,
servicefrequencies).Thesevaluedifferencesarethanusedtocalculateanattractiv-
ityindicatorA,whichpredictsifachainwillbemoreorlessattractivethanalter-
nativechains.
2.2.Modelingcosts
Theannualcostsforoperatingatruckarebeingcalculatedthroughthefollow-
ingfunction(alsocompareMichalk,Meimbresse2012):
CAi=CSIai+CMai+CDi+CEi+CIi+CREi+COi+CTi+CIni
Thecostspertripcanthenbecalculatedas:
CRi=CAi/nRi
AsthetransportchainisdescribedbythecostsoftrucktransportandRoRo-
ferrytransport,inthismodel,thecostsofatransportchain(pertrip)canbecalcu-
latedas:
CIT=Ctj+∑CRi
