Integrated timetable rescheduling and passenger reassignment during railway disruptions
Zhu, Y.; Goverde, R.M.P.
DOI
10.1016/j.trb.2020.09.001
Publication date
2020
Document Version
Final published version
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Transportation Research. Part B: Methodological
Citation (APA)
Zhu, Y., & Goverde, R. M. P. (2020). Integrated timetable rescheduling and passenger reassignment during
railway disruptions. Transportation Research. Part B: Methodological, 140, 282-314.
https://doi.org/10.1016/j.trb.2020.09.001
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ContentslistsavailableatScienceDirect
Transportation
Research
Part
B
journalhomepage:www.elsevier.com/locate/trb
Integrated
timetable
rescheduling
and
passenger
reassignment
during
railway
disruptions
Yongqiu
Zhu
∗,
Rob M.P.
Goverde
Department of Transport and Planning, Delft University of Technology, The Netherlands
a
r
t
i
c
l
e
i
n
f
o
Article history: Received 17 July 2019 Revised 18 August 2020 Accepted 1 September 2020 Keywords: Railways Disruption management Timetable rescheduling Passenger reassignment Fix-and-optimize algorithma
b
s
t
r
a
c
t
During railwaydisruptions,mostpassengers may not beableto findpreferred alterna-tivetrainservicesduetothecurrentwayofhandlingdisruptionsthatdoesnottake pas-sengerresponsesintoaccount.Toofferbetteralternativestopassengers,thispaper pro-posesanovelpassenger-orientedtimetablereschedulingmodel,whichintegratestimetable reschedulingandpassengerreassignmentintoaMixedIntegerLinearProgrammingmodel withtheobjectiveofminimizinggeneralizedtraveltimes:in-vehicletimes,waitingtimes atorigin/transferstationsandthenumberoftransfers.Themodelappliesthedispatching measuresofre-timing,re-ordering,cancelling,flexiblestoppingandflexibleshort-turning trains, handles rolling stockcirculations at bothshort-turning and terminal stations of trains,andtakesstationcapacityintoaccount.Tosolvethemodelefficiently,anAdapted Fix-and-Optimize(AFaO)algorithmisdeveloped.Numericalexperimentswerecarriedout toapart oftheDutchrailways.The resultsshow that theproposed passenger-oriented timetablereschedulingmodelisabletoshortengeneralizedtraveltimessignificantly com-pared toanoperator-orientedtimetablereschedulingmodel thatdoesnotconsider pas-sengerresponses. Byallowing only10minmore traindelaythanan optimal operator-orientedreschedulingsolution,thepassenger-orientedmodel isabletoshortenthe gen-eralized traveltimesoverallpassengers bythousands ofminutesinall considered dis-ruptionscenarios.Withapassenger-orientedrescheduledtimetable,morepassengers con-tinuetheirtraintravelsafter adisruptionstarted, comparedtoarescheduledtimetable fromthe operator-orientedmodel.The AFaOalgorithmobtains high-qualitysolutions to thepassenger-orientedmodelinupto300s.
© 2020TheAuthor(s).PublishedbyElsevierLtd. ThisisanopenaccessarticleundertheCCBY-NC-NDlicense (http://creativecommons.org/licenses/by-nc-nd/4.0/)
1. Introduction
Railwaysystemsplayanimportantroleinpeople’sdailytravellingsothattheoperationsarerequiredasreliableas pos-sibletoensurepassengerpunctuality.Unfortunately,unexpecteddisruptionsoccurintherailwaysonadailybasis(Zhuand Goverde,2017),duringwhichmanytrainservicesaredelayedandcancelledthatdisturbpassengerplannedjourneys signifi-cantly.Whenreschedulingatimetableincaseofadisruption,trafficcontrollersdecidewhichserviceshavetobedelayedor cancelledintermsofpre-designedcontingencyplans,wheretheimpactonpassengersisconsideredtoaverylimitedextent
∗ Corresponding author.
E-mail addresses: y.zhu-5@tudelft.nl (Y. Zhu), r.m.p.goverde@tudelft.nl (R.M.P. Goverde).
https://doi.org/10.1016/j.trb.2020.09.001
0191-2615/© 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )
(Ghaemietal., 2017b).As a result,therescheduled trainservices maynot be passenger-friendly.Forexample,passengers mayhardly find alternative train services to reach the expecteddestinations in reasonabletravel times. Toprovide pas-sengerswithbetteralternatives duringdisruptions, itisnecessarytorescheduleatimetableinamorepassenger-oriented way.
1.1. Thestate-of-the-artontimetablerescheduling
Passenger-oriented timetable rescheduling started from the field of delay management that decides whether a train should wait for a delayed feeder train to guarantee the transfer connection of some passengers. Schöbel (2001) is the first one dealing with this problem based on the assumption that if passengers missed the transfer connections, they would wait for a complete cycletime to catch the next connection considering that the planned timetable is periodic.
Dollevoetetal.(2012)make anextension byintroducingthe possibilityofrerouting passengers whoareassumedtotake theshortestpathsfortheirfollowingtravelsincaseofmissedtransfers.Bothpapersdescribetheinfrastructureata macro-scopiclevelneglecting signalsandblock sections.Toimprovesolutionfeasibilityinpractice,Cormanetal.(2017) propose adelaymanagement modelin whichtheinfrastructure isdescribedata microscopiclevel.Albert etal.(2017) formulate passengerbehavioursinstations(e.g.queueinginboarding trains)atamicroscopiclevelto describepassengerinfluences ontraindelaysratherthanconsideringtheimpactoftraindelaysonpassengerbehavioursonly.
Delay management deals with the interaction between timetable and passengers, but not the interaction between timetableandreduced infrastructureavailability,which howevermust be takeninto account by disruptionmanagement. Operator-orienteddisruptionmanagementconsidersonlythelatterkindofinteraction,whilepassenger-orienteddisruption managementconsidersbothkindsofinteractions.Inpractice,disruptionmanagementconsistsofthreephasesstartingfrom thedisruptiveevent(failure)(Ghaemietal.,2017b).Thefirstphaseconsistsofgettinginformationaboutthedisruptionand itslocation,guaranteeingsafety,estimatingtheexpecteddurationanddecidingonthereschedulingmeasures.Inthesecond phasetherescheduledtimetableisappliedandinthethirdphasethetrafficrecoverstotheoriginaltimetable.Atpresent, thefirstphasecantakeupquitesome timedependingonhowexistingcontingencyplansneedtobe adjusted,howmany changeshavetobemadetothedispatchingplans,andhowdriverscanbeinformedofdisruptionsahead.Speedingupthis processisrequiredtoavoidqueuingofstrandedtrains.Atimelimitof5minutetocomputeareschedulingsolutionwillbe sensibleformainlinerailwaynetworksandwouldimplyabigimprovementon thecurrentpractice.Notethatthispaper handlesseriousdisruptionsofblockedtracksthatgobeyondsimplere-timingorre-orderingdecisions.
Mostliterature ondisruption management is operator-oriented,including(Ghaemietal., 2017, 2018;Meng andZhou, 2011;Veelenturf etal., 2015;Zhan etal.,2015, 2016;Zhu andGoverde,2019). Thedifferences amongthesepaperslie in theconsidered railwaylines(single-track linesordouble-track lines),the adopteddispatchingmeasures, whether consid-eringthe transition from the planned timetable to the disruption timetable andvice versa, the extent of infrastructure description(macroscopicormicroscopiclevel),thenumberofconsidereddisruptions(singledisruptionormultiple disrup-tions),and/orthecharacteristicofdisruptionlength(deterministicoruncertain).Thesimilarityamongthesepapersisthat theyalluseoperator-orientedobjectives:e.g.,minimizingtraindelaysand/orcancellations,inwhichaconstantcancellation penalty isused to representthedelay ofcancellingeach train. There area few papers that considerboth operators and passengers.Bettinelli etal.(2017)associatedispatching decisionswithdifferentpenaltiesconsidering theextents oftheir impactsonpassengers.Forexample,amajorchangeinatrainpathisassociatedwithabiggerpenality.Louwerseand Huis-man(2014)includeatermintheobjectivetobalancethenumbersofcancelledtrainsinbothdirectionstodistributethe disruptionimpactevenlyoverthedifferentpassengergroupsincaseofpartialtrackblockage.
Afew works focuson passenger-oriented disruption management. Cadarsoetal. (2013) propose a two-step approach inwhich a frequency-based passenger assignment model isperformed first toestimate thepassenger demand andthen areschedulingmodel (fortimetableandrollingstock) issolved toaccommodate thepassenger demandasmuch as pos-sible.The adopteddispatching measures are limitedto cancellingoriginal trains andinserting additionaltrains. Zhu and Goverde(2019c)adopta schedule-basedpassengerassignmentmodeltoobtainthetravel pathofeachpassengerinterms ofthe plannedtimetable.Withthisinformation, thepotential impact ofeach dispatchingdecision onpassenger planned travelsisestimated,whichisusedasweightintheobjectivetominimizingpassengerdelays.Theadopteddispatching mea-suresincludere-timing,re-ordering,cancelling,flexiblestopping(i.e.addingextrastopsandskippingscheduledstops),and flexibleshort-turning.Short-turninga trainmeansthat atrain stopsatthelast possiblestationbeforethe blockedtracks andthecorrespondingrollingstockturnsatthatstationtoservetheoppositeoperation.Flexibleshort-turningmeansthat each trainis givena full choiceof short-turningstation candidates,andthe modeldecides the optimalstationandtime ofshort-turningatrain.BothCadarsoetal.(2013) andZhuandGoverde(2019c)considerstaticpassengerdemand,which neglectthatpassengersmaychooseother travelpathsratherthantheplannedonesduetotherescheduledtrainservices. Toformulatepassengerbehaviourinamorerealisticway,itisnecessarytotakeintoaccountpassengerresponses towards therescheduled trainservices. Veelenturfet al.(2017)propose an iterativeapproach that embedsa timetable reschedul-ingmodel andapassenger assignment modelintoan iterativeframework whereateach iteration an adjustmentwillbe appliedonthetimetableifit reducesthe totalpassengerinconvenienceasevaluatedby thepassengerassignmentmodel. The adjustments are restricted to adding stops. Binder et al. (2017) propose an integrated approach of formulating the timetablereschedulingandthepassengerassignmentintoone singlemodelthat computesarescheduledtimetablebyan optimizationsolverdirectly. Theapplied dispatchingmeasures includere-timing,re-ordering,cancelling, globalre-routing
and insertingadditional trains. The rolling stockcirculations at the short-turningand terminal stations oftrains are ne-glected.Gaoetal.(2016)alsoproposeatimetablereschedulingmodelconsideringdynamicpassengerflows,whilefocusing ontherecovery phase ofa disruption.Asthe targetcaseisametro corridor,allpassengers areassumedtochoosedirect trains(i.e.notransfers).Thedispatchingmeasuresofstop-skippingandre-timingareusedtoadjustthetimetabletoreduce passengerwaitingtimesatstations.Duetothecomputationalcomplexity,themasterproblemofgeneratingarescheduled timetableisdecomposedintoaseriesofsub-problemsthat eachreschedulesone trainonly.When solvingasub-problem foronetrain,thestoppingpatternsandtimeschedulesofthepreviousconsideredtrainsareallfixed.
1.2. Thescientificgapsonpassenger-orientedtimetablerescheduling
Formulatingpassengerre-routingasamulti-commodityflowproblemisamethodcommonlyusedintheliterature.For exampleinBinder etal.(2017)andCormanetal.(2017),atimetableisformulated intoadirectedacyclicgraph(DAG)to describepassengerpathchoices.Then,thepassengerre-routingismodelledasamulti-commodityflowproblem,inwhich passengers flow through the arcs of the DAG that is updated according to the rescheduled timetable. The challengesof modellingpassengerre-routingthiswaymainlylieintwoaspects:(1)howtoformulateaDAGfromatimetabletodescribe morepathattributeswithlimitednodes/arcs,and(2)howtoreformulateaDAGdynamicallyduringtimetablerescheduling whenpassenger re-routingisintegrated. Theexisting literatureeitheruses asimplemethodofformulating aDAG,which cannot reflectcertain path attributes(e.g. the number oftransfers), oradopts a formulation method that will lead to a large-size ofDAG iffocusing on arailway networkwithhigh-frequency services. Also,limited dispatchingmeasures (e.g. no flexible stopping) are used inthe literature, which need tobe extended to explore more alternative pathchoices for passengersduringdisruptions.However,includingmoredispatchingmeasureswillincreasethecomplexityofreformulating aDAGduringtimetablerescheduling.Anotherchallengeisdesigninganefficientalgorithmtosolvetheintegratedtimetable reschedulingandpassengerre-routingmodelwithhigh-qualitysolutionsinanacceptabletime.Thishasbeenreportedasa challengingtaskintheliteraturesofar(Cormanetal.,2017;Binderetal.,2017).
1.3. Thecontributionsofthispaper
Thispapercontributestotheliterature byimprovedmethodsofDAGformulationandreformulationtoenableabetter integratedtimetablereschedulingandpassengerre-routingmodelintermsoftheconsiderationsofmultiplepathattributes andmultiple dispatchingmeasures. Thispaperalsocontributes withan efficientalgorithm tosolve theintegratedmodel withoptimalornear-optimalsolutions.Thekeycontributionsofthispaperaresummarizedasfollows.
• AnimprovedmethodofformulatingaDAG(calledanevent-activitynetworkinthispaper)fromatimetableisproposed, byexplicitlydistinguishingpassengeractivities atoriginstations,transferstations (ifany)andtrainswithouttime dis-cretization.
• Anewconcept,the transitionnetwork,isproposed toenablethedynamicformulationofevent-activitynetworks con-sideringtheimpactsofmultipledispatchingmeasures,thecharacteristicsofthedisruption,theoperationalrequirements oftrains,andthetravelrequirementsofpassengers.
• Forthefirsttime,thedispatchingmeasureofflexiblestopping(addingandskippingstops)isformulatedwithpassenger re-routinginarailwaynetwork(insteadofonecorridor)wheretransfersareallowed.
• Anadaptedfix-and-optimize(AFaO)algorithmisdesignedtoiterativelysolvetheproposedpassenger-orientedtimetable reschedulingmodel.The algorithmallowsto balancethesolutionqualityandcomputationtimeby changingtheinput parameter.
• Thepassenger-orientedtimetablereschedulingmodelisabletogeneratereschedulingsolutionswithshortergeneralized travel times than an operator-oriented model according to results of real-life instances in part of the Dutch railway network.
This paper considers single disruption that blocks tracks between stations completely assuming that the duration of the disruptionis knownatthebeginning ofthe disruption,andwill notchange overtime. We describeinfrastructure at a macroscopiclevel andhandle railwaynetworkswith bothsingle-track anddouble-track railway lines.We use the dis-patchingmeasures ofre-timing, re-ordering,cancelling, flexibleshort-turning,andflexible stoppingto computea feasible rescheduled timetablefromthe start ofa disruption untilit is fullyrecovered. Atrain isassumed tohave unlimited ca-pacity,which meansthat a passengeris ableto boardanytrain ifhe/shedecides toboardthistrain. Thisis becausewe focus onproviding better alternative trainservices to passengers so that thepossible impact ofvehicle capacityon pas-sengersisneglected. Inthisway,wecan gettheoptimalrescheduledtimetableintermsofgeneralizedtravel times.This optimalrescheduled timetablecan thenbe used asaninput to rollingstockreschedulingthat aims toaccommodate the passenger demand asmuch aspossible.Forexample, Kroon etal.(2014) andVan derHurk etal.(2018) both deal with passenger-orientedrollingstockreschedulingwitharescheduledtimetablegivenasinput.
The remainder of the paper is organized asfollows. Section 2 introduces the general framework of establishing the passenger-oriented timetablerescheduling model.Section 3 explainshow to formulate a timetableinto an event-activity network,whichisadirectedacyclicgraphwitheventsasnodesandactivitiesasarcstodescribepassengerpathchoices.A
Fig. 1. An overview of the passenger-oriented timetable rescheduling model.
pathisconstitutedbyaseriesofconnectedeventsandactivities.Theplannedtimetablecan beformulatedintoan event-activitynetwork
plan,whichisthenextendedtoatransitionnetwork
∗thatenablesthedynamicformulationof event-activity networks duringtimetable rescheduling. A transition network is a combination of all events and activities that couldbeinanyevent-activitynetworksformulatedfromfeasiblerescheduledtimetablestowardsthedisruptionconcerned.
Section4introducesthemethodofconstructingatransitionnetwork.Basedonatransitionnetwork,thepassenger-oriented timetablereschedulingmodelisproposedinSection 5followedbySection6that introducesthemethodsofreducing the computational complexityofthe model.InSection 7, extensivenumerical experimentswere carried out toa partof the Dutchrailways.Finally,Section8concludesthepaperandpointsoutfutureresearchdirections.
2. Generalframework
Thispaperintegratestimetablereschedulingwithpassengerre-routingintoanMILPmodel,forwhichtwopreprocessing stepsareneeded.Fig.1givesanoverviewofthemodel.
The first preprocessing step transforms the planned timetable into an event-activity network
plan, which is a
di-rectedacyclicgraphusedtodescribe passengerpath choices.The methodofconstructingan event-activity networkfrom atimetableisintroduced inSection 3.Incaseofa disruption,theplannedtimetablewill becomeinfeasible,andsodoes thecorrespondingevent-activity network
plan thatnowisunable toreflectthepaths currentlyavailable intherailways.
Underthiscircumstance,thetimetablehastoberescheduled,andduringreschedulingthecorrespondingevent-activity net-workshavetobeupdatedaswelltoconsidertimetable-dependentpassengerbehaviours.Toenableadynamicevent-activity networkformulationduringtimetablerescheduling,weperformthesecondpreprocessingsteptoconstructatransition net-work
∗. Atransitionnetworkisextended fromtheevent-activity network
plan by addingall eventsandactivitiesthat could exist in any event-activity network
dis corresponding to a feasible rescheduled timetable obtainedfor a specific
disruption.Inother words,
∗=i
idis∪
plan,where
idis refers tothe event-activitynetwork corresponding tothe ith
feasiblerescheduledtimetable.Foronespecific disruptionthereareusually multiplefeasiblerescheduledtimetables.Note that
∗varieswiththedisruptioncharacteristics (i.e.location andstarting/endingtime)andthedispatchingmeasures al-lowed.Atransitionnetwork
∗ isnotadirectedacyclicgraphasitincludesthepossibilityofchangingtheorderoftrains. ThemethodofconstructingatransitionnetworkisintroducedinSection4.
Table 1 Event attributes.
Symbol Description
st e The corresponding station of event e ∈ E \ E penal
tr e The corresponding train of event e ∈ E ar ∪ E de ∪ E dde
tl e The corresponding train line of event e ∈ E ar ∪ E de ∪ E dde
λe The corresponding departure event of e ∈ E dde
o e The scheduled time of event e ∈ E ar ∪ E de ∪ E dde
The constructed transitionnetwork,the plannedtimetable, the disruption characteristics,andthe allowed dispatching measures are all necessary inputsto establishthe passenger-orientedtimetable reschedulingmodel,which is formulated as an MILP in this paper. This model consists of the constraints for three purposes: 1) timetable rescheduling, 2) dy-namic event-activity network formulation,and3) passenger reassignment. The timetable reschedulingconstraints ensure a rescheduled timetable does not violate anyinfrastructure andoperational restrictions. The constraints relevant to the dynamicevent-activity network formulationdecide whichactivities andeventsof
∗ should be selected toconstruct an event-activitynetwork
dis intermsofarescheduledtimetable.Thepassengerreassignmentconstraintsdecidetheweight
ofeachactivityof
disfromtheperspectivesofpassengers,andassigneachpassengertoonepathonly.Apathisdescribed
by a sequenceof connectedactivities. The totalactivity weightof apath is thegeneralizedtravel time ofthis path.The objectiveofthemodelisminimizingthegeneralizedtraveltimesofallpassengers.Bythismodel,arescheduledtimetable that leadstothe shortestgeneralizedtravel timesofall passengers can beobtained, aswell asthe pathchosen by each passengerundertherescheduledtimetable.
3. Event-activitynetwork
Thissectiondefinesanevent-activitynetwork,whichisarepresentationofatimetableandallowspassengerpathchoices to be described. Anevent-activity network needs to be reconstructedifthe corresponding timetableis rescheduled.This sectionintroduceshowtoformulateanevent-activitynetworkgivenafixedtimetable.
3.1. Events
Sixtypesofeventsarecreatedinan event-activitynetwork.Theyare arrivalevents,departure events,duplicate depar-tureevents, entryevents,exitevents anda penalty event, whichconstitute the sets Ear, Ede,Edde,Eentry,Eexitand Epenal,
respectively. Inparticular,Ear=Ealightar ∪Earpass, andEde=Edeboard∪E pass
de , whereE alight
ar isthe setofarrival eventsthat
corre-spondtopassenger alighting,andEboard
de isthe setofdeparture eventsthatcorrespond topassengerboarding.The arrival
(departure)eventsassociatedtoathroughtrainthatdonotcorrespondtopassengeralighting(boarding)constitutetheset ofEarpass(Epassde ).
The attributes of events are indicated in Table 1. Note that an event e ∈ Edde is the duplicate of a departure event
e∈Eboard
de withexactly the sameattributes whiche has, andwithan extra attribute
λ
e toindicate the departure eventecorrespondingtoe:Edde=
{
e|
λ
e=e,e∈Edeboard}
.Oneandonlyoneduplicateiscreatedforadepartureevente∈Edeboard.Duplicate departure eventsare used forconstructing wait, boarding andtransfer activities, which are explained inmore detailinSection 3.2.Notethat thispaperdefinestheseactivitiesdifferentlythanZhuandGoverde(2019a).AsforEpenal,it
containsonlyonepenalty eventforconstructingthepenalty arcsthatenablepassengerswho cannotfindpreferredpaths toleavetherailways.
3.2. Activities
Anactivityisadirectedarcbetweentwodifferentevents.Tentypesofactivitiesarecreatedinanevent-activitynetwork, whichareconstructedasfollows.
Aentry=
{
(
e,e)
|
e∈Eentry,e∈Edde,ste=ste}
.Entryactivitiesenablepassengerstoentertherailwayswhenarrivingattheorigins.
Aexit=
{
(
e,e)
|
e∈Earalight,e∈Eexit,ste=ste}
. Exitactivities enablepassengers toleave the railwayswhenarriving atthedestinations, Aenpenal=
e,ee∈Eentry,e∈Epenal ,andAexpenal= eee∈Epenal,e∈Eexit.Entrypenaltyactivitiesandexitpenalty activitiestogetherenablepassengerstodroptherailwaysincasenopreferredpathscanbefound,
Aboard=
e,ee∈Edde,e∈Eboard de ,e=λ
e.Boardingactivitiesenablepassengerstoboardatrain.Eachduplicate depar-tureeventislinkedtoitscorrespondingdepartureevent.
Arun=
e,ee∈Ede,e∈Ear,tre=tre,ste istheupstreamstationadjacenttoste.Runningactivitiesenablepassengers totravelfromonestationtoanotherinatrain.
Fig. 2. A planned timetable with the constructed transition network.
Adwell=
e,ee∈Earalight,e∈Eboard
de ,tre=tre,ste=ste,oe− oe>0
.Dwellactivitiesenablepassengerstowaitata sta-tioninatrain.
Apass=
e,ee∈Earpass,e∈Epassde ,tre=tre,ste=ste,oe− oe=0. Pass-through activities enable passengers to passthroughastationina train.Notethat itisnecessarytodistinguish theplannedpass-throughanddwellactivitiessothat wecanrecognizetheskipped(extra)stopsinarescheduledtimetablebecausethedispatchingmeasureofflexiblestopping isappliedinthispaper.
Await=
e,e
e∈Edde,e=argminoe
|
oe ≥ oe,e∈Edde,tre=tre,ste=ste.Waitactivitiesenablepassengerstowait
atastation.Eachduplicatedepartureeventislinkedtothenexttime-closestduplicatedepartureeventthatisatthesame stationbutcorrespondstoanothertrain.
Atrans=
e,e
e∈Earalight,e=argminoe
|
oe≥ oe+transe,e ,e∈Edde,tre =tre,ste=ste. Transfer activities enable pas-sengerstotransferfromonetraintoanother.Eacharrivaleventislinkedtothenexttime-closestduplicatedepartureevent thatoccursatleasttrans
e,e later atthesamestation butcorrespondsto anothertrain.Here, transe,e represents theminimum
transfertimerequiredfromthearrival traintre to anotherdeparturetraintre, whicharealongsidethesameplatformor
differentplatformsaffectingthevalueoftrans e,e .
Anevent-activitynetworkis
=
(
E,A)
,whichisadirectedacyclicgraph(DAG).IntheblueboxofFig.2,allnodesand arcscoloredinblackconstituteanevent-activitynetworkformulatedfromtheplannedtimetableshownintheleft.3.3.Weightsofactivities
Theweightsofactivitiesaredeterminedasfollows:
wa=
β
vehicle(
oe− oe)
, a=(
e,e)
∈Arun∪Adwell∪Apass,wa=
β
wait(
oe− oe)
, a=(
e,e)
∈Await,wa=
β
wait(
oe− oe)
+β
trans, a=(
e,e)
∈Atrans,wga=oe− tgori, a=
(
e,e)
∈Aentry:oe≥ torigwga=Tmax
g , a=
(
e,e)
∈Aenpenalwa=0, a=
(
e,e)
∈Aboard∪Aexit∪Aexpenal,where
β
vehicle andβ
wait representrespectivelypassengerpreferenceonin-vehicletimesandwaitingtimesatstations,andβ
trans refers to the time penalty of one transfer. Note that the weight of an entry activity or entry penality activity ispassengerdependent. tori
g isthe time when passenger group garrives at theorigin station,andthis paperassumesthat
eachpassengergroupghasanacceptablemaximumgeneralizedtraveltimeTmax
Table 2
Sets relevant to a transition/event-activity network. Notation Description
∗ Transition network: ∗= ( E ∗, A ∗)
plan Event-activity network formulated from the planned timetable: plan =
E plan , A planand plan ⊂∗
dis Event-activity network formulated from any possible disruption timetable by adjusting the planned timetable: dis ⊂∗
E ∗ Set of events in ∗
E plan Set of events in
plan : E plan ⊂ E ∗
E plan
i Set of i events in plan , i ∈ {ar, de, dde, entry, exit, penal}: E i ⊂ E plan plan
E alight, plan
ar Set of arrival events that correspond to passenger alighting in plan : E alightar , plan⊆ E arplan
E pass, plan
ar Set of arrival events that do not correspond to passenger alighting in plan : E passar , plan= E arplan\ E alightar , plan
E board, plan
de Set of departure events that correspond to passenger boarding in plan : E deboard, plan⊆ E plan de
E pass, plan
de Set of departure events that do not correspond to passenger boarding in plan : E depass, plan= E plan de \ E board, plan de A ∗ Set of activities in ∗ A ∗
i Set of i activities in ∗: A ∗i ⊂ A ∗, i ∈ {wait, trans, board, entry, exit} A plan Set of activities in
plan : A plan ⊂ A ∗
A plan
i Set of i activities in plan : A plani ⊂ A plan , i ∈ {run, dwell, pass, wait, trans, board, entry, exit, enpenal, expenal}
A undis
k Set of undisrupted k activities in ∗: A undisk ⊂ A plank , k ∈ {run, dwell, pass, wait, trans, board, entry, exit} A dis
k 1 Set of disrupted k 1 activities in
∗: A dis
k 1 = A
plan
k 1 \ A
undis
k 1 , k 1 ∈ {run, dwell, pass} A dis
k 2 Set of disrupted k 2 activities in
∗: A dis
k 2 = A
∗
k 2\ A
undis
k 2 , k 2 ∈ {wait, trans, board, entry, exit}
4. Transitionnetwork
Thissectiondefinesa transitionnetwork,whichallows adynamicevent-activitynetworkformulationduringtimetable rescheduling.Thetransitionnetwork
∗ isanextension oftheevent-activity network
plan formulatedfromtheplanned
timetablebyaddingalleventsandactivitiesthatcouldexistinanyrescheduledtimetables.Inotherwords,
∗representsall possibletimetableadjustments,whichcanbeusedtodescribethealternativepathsavailabletopassengersduringtimetable rescheduling.Beforegivingthedetailsofconstructingatransitionnetwork,anexampleonasimplecaseisgivenbelowto explainthebasicidea.
ExampleFig.2showsaplannedtimetablewiththreestations A,BandC,andtwotrainstr1 andtr2.Bothtrainsstart
fromAandendatBwithtraintr1 additionallystoppingatB.Inthebluebox,theeventsandactivities inblackconstitute
theevent-activitynetwork
plan fromtheplannedtimetable, whiletheeventsandactivities inblackandorangetogether
constitutethetransitionnetwork
∗.Inthiscase,
∗isextendedfrom
planby addinganeweventandeightnew
activ-ities(coloredinorange)thatdonot existintheplannedtimetablebutcouldexistinarescheduled timetable.Duetothe dispatchingmeasureofre-ordering,traintr1coulddepartlaterthantraintr2 atstationA,althoughtraintr1 wasoriginally
plannedtodepart earlierthan traintr2.Consideringthispossibletrain orderchange,an extrawait activityisaddedfrom
event(dde,tr2,A)toevent(dde,tr1,A),whichcreatesacyclebetweenbothevents.Thisdisablesatransitionnetworktobe
aDAG.Duetothedispatchingmeasureofflexiblestopping,anextrastop couldbeaddedtotraintr2 atstationB.Thus,a
newevent(dde,tr2,B)isaddedaswellasanentryactivity,aboardingactivity,awaitactivity,twotransferactivities,and
anexitactivity.Ascanbeseenentry/exitpenaltyactivitiesalwaysremainthesamein
∗asin
plan.
In the following, we introduce how to construct a transition network by extending the event-activity network
plan
correspondingtoa plannedtimetable.Thesetnotationwiththesuperscriptofplanrepresentstheevents/activitiessetsin
plan.Thesetnotationwiththesuperscriptof∗representstheextendedevents/activitiesin
∗.Table2showsthenotation
ofsetsrelevanttoatransition/event-activitynetwork.
4.1. Extendedevents
Alleventsofevent-activitynetwork
planareincludedinthetransitionnetwork
∗,inwhichonlythesetofduplicate departureeventsisextended
Edde∗ =
eλ
e=e,e∈Edeplan, whereEdeplan=Edeboard,plan∪Edepass,plan.Here, Edeboard,plan andEdepass,plan representrespectively thesetofdepartureeventsthatcorrespondanddonotcorrespondtopassengerboardingintheplannedtimetable.Recall thatinanevent-activitynetwork,duplicatesareonlycreatedfordepartureeventsthatcorrespondtopassengerboarding.
4.2. Extendedactivities
All activities ofevent-activity network
plan are included inthe transitionnetwork
∗, inwhich five typesof
activi-tiesareextendedincludingA∗wait,A∗trans,A∗board,A∗entry andA∗exit.Exceptentry/exit penaltyactivities,each typeofactivitiesis classifiedintotwosubsets,undisruptedanddisrupted:
Aplani =Aundis
i ∪Adisi , i∈
{
run,dwell,pass}
,A∗k=Aundis
Wedefinean activityanundisrupted activityifbothofthetwoeventsinthisactivitywereoriginallyplannedto occur beforetstart or aftertend+R, inwhich R isthe time length required forthe normalschedule to be fullyrecovered after
thedisruption ends. Inthat sense, an undisrupted activity isan activity that willnever be differentthan plannedin the rescheduledtimetable.In thispaper,we ensurean arrival(departure) eventthat wasoriginally scheduledtooccur before thedisruption start tstart oratleast Rminutes laterthan the disruptionendtend will not bedelayed/cancelled. Thisalso
appliestoduplicatedeparture events,which arealwayswiththesameoccurrencetimesastheir correspondingdeparture events.We define an activitya disrupted activityif atleast one of the two eventsin thisactivity could be cancelledor delayed.Inthatsense,adisruptedactivityisan activitythatcouldbedifferentthanplannedintherescheduledtimetable. Thispaper requiresthat only the events,which were originally plannedto occur duringthe period [tstart,tend+R] could
becancelledordelayed.Theseeventscan correspondtoanystations,whicharenot distinguishedbetweendisruptedand undisruptedinthepaper.Basedonthese,wedecidewhetheranactivityisundisruptedordisruptedasfollows.
4.2.1. Running,dwell,andpass-throughactivities
Thedisruptedandundisruptedrunning,dwell,andpass-throughactivitiesarerespectivelydefinedas
Adis
i =
e,e
∈Aplani|
tstart≤ oe<tend+Rortstart≤ oe<tend+R, i∈
{
run,dwell,pass}
,Aundis
i =A
plan
i
\
Adisi ,i∈{
run,dwell,pass}
,whereoe refers to the original scheduledtime of e, tstart (tend) represents the start (end) time of the disruption,and R
representsthedurationrequiredforthedisruptiontimetableresumingtotheplannedtimetableafterthedisruptionends.
4.2.2. Entry,exit,andboardingactivities
ThedisruptedentryactivitiesaredefinedasAdis
entry=Adisentry,1 ∪Adisentry,2,where
Adisentry,1 =
e,e∈Aplanentry|
tstart≤ oe<tend+R,
Aentrydis,2 =
e,ee∈Eentryplan,e∈Edde∗\
Eddeplan,ste=ste,tstart≤ oe <tend+R.
ThedisruptedexitactivitiesaredefinedasAdis exit=A
dis,1 exit ∪A
dis,2 exit,where
Adisexit,1=
e,e∈Aplanexit|
tstart≤ oe<tend+R,
Adisexit,2=
e,ee∈Earpass,plan,e∈Eexitplan,ste=ste,tstart≤ oe<tend+R. ThedisruptedboardingactivitiesaredefinedasAdis
board=A
dis,1 board∪A
dis,2
board,where
Adisboard,1 =
e,e∈Aplanboard|
tstart≤ oe<tend+R,
Adisboard,2 =
e,ee∈Edde∗\
Eplandde,e∈Edepass,plan,e=λ
e,tstart≤ oe<tend+R.
Aentrydis,1,Adisexit,1,andAboarddis,1 representrespectivelytheentry,exit,andboardingactivitiesthatcouldbecancelledduetothe disruption.Adisentry,2,Adisexit,2, andAboarddis,2 representrespectivelytheentry,exit,andboardingactivities thatare notin
plan but mightbe neededduetoextrastopsaddedina rescheduledtimetable.Theundisrupted entry,exit,andboardingactivities arerespectivelydefinedasAundis
entry=A
plan
entry
\
Adisentry,1,Aundisexit =A plan exit\
Adis,1
exit,andAundisboard=A plan board
\
Adis,1 board.
4.2.3. Waitactivities
To construct disrupted wait activities, we first define three event sets, Emax
dde =
{
argmax{
oe|
e∈E plandde,oe<tstart,ste=
st
}}
st∈ST, Eddemin={
argmin{
oe|
e∈E plandde,oe≥ tend+R,ste=st
}}
st∈ST, and Eddedis ={
e∈Edde∗|
tstart≤ oe<tend+R}
, in which ST isthesetofstations.Set Emax
dde includesateachstation st∈STthelatestduplicate departureeventbeforetstart. SetEddemin
in-cludesateach stationst ∈STtheearliestduplicatedeparture eventaftertend+R.The eventsinEddemax andEmindde willnot be
affectedbythedisruption,whileEdis
dde includesallduplicatedepartureeventsthatcouldbeaffectedbythedisruption.
BasedonEmax dde,E
min
dde andE
dis
dde,thesetofdisruptedwaitactivitiesisdefinedasA dis wait=
j∈{1,...,4}Adiswait,j,inwhich
Adiswait,1=
e,ee∈Emaxdde,e∈Edisdde,ste=ste,oe− oe≤ maxwait
,Adiswait,2=
e,ee∈Edis dde,e∈Emin
dde,ste=ste,oe− oe≤ maxwait+D
, Adiswait,3=
e,ee,e∈Edisdde,e=e,ste=ste,0≤ oe− oe≤ maxwait+ D
,Adiswait,4=
e,ee,e∈EdisTable 3 Decision variables.
Symbol Description Module
x e Continuous variable deciding the rescheduled time of an event e ∈ E plan
ar ∪ E deplan ∪ E dde∗ . 1, 2, 3
c e Binary variable with value 1 deciding event e ∈ E plan
ar ∪ E plande ∪ E ∗dde is cancelled, and 0 otherwise. 1, 2
s a Binary variable deciding whether a scheduled stop a ∈ A plan
dwell is skipped or 1,
2 whether an extra stop is added to a ∈ A plan
pass .
If a ∈ A plan
dwell , then s a = 1 indicates a is skipped.
If a ∈ A plan
pass , then s a = 1 indicates a is added with a stop.
y a Binary variable with value 1 deciding activity a ∈ ∗is effective in
dis , and 0 otherwise. 2, 3
u g a Binary variable with value 1 deciding activity a ∈ ∗is chosen by passenger group g , and 0 otherwise. 3
w g a Continuous variable deciding the weight of activity a ∈ ∗perceived by each passenger in group g 3
Module 1: timetable rescheduling; Module 2: dynamic event-activity network formulation; Module 3: passenger reassignment
Here, D represents the maximum allowed delay per event, and max
wait represents the maximum waiting time that a
passenger would like to spend at a station. We assume that max
wait≥ D. Then, undisrupted wait activities are defined as
Aundis wait =A plan wait
\
(
A plan wait∩A dis wait)
. 4.2.4. TransferactivitiesTo construct disrupted transfer activities, we first establish two event sets, Edis
ar =
{
e|
e∈Earplan,tstart≤ oe<tend+R}
,and Etrans
ar =
{
e|
e∈Eplan
ar ,oe<tstart,
(
e,e)
∈Aplantrans,tstart≤ oe<tend+R}
. Eardis includes the arrival events that could bede-layed/cancelledduetothedisruption.Etrans
ar containsthearrivaleventsthatwillnotbedelayed/cancelledbythedisruption
butthecorrespondingplannedtransferactivitiescouldbecancelledduetothedisruption. BasedonEdis
ar andEartrans,thedisruptedtransferactivitiesaredefinedasAdistrans=
j∈{1,...,5}Adistrans,j,where
Adistrans,1=
e,ee∈Etransar ,e∈Emindde,tre=tre,ste =ste,e,etrans ≤ oe− oe≤ maxtrans
, Adistrans,2=
e,ee∈Etransar ,e∈Edisdde,tre=tre,ste =ste,oe− oe≤ maxtrans
, Adistrans,3=
e,ee∈Edisar ,e∈Eddemin,tre=tre,ste =ste,transe,e ≤ oe− oe≤ maxtrans+D
, Adistrans,4=
e,ee∈Edisar ,e∈Edisdde,tre=tre,ste =ste,0≤ oe− oe≤ maxtrans+D
, Adistrans,5=
e,ee∈Edisar,e∈Eddedis,tre=tre,ste=ste,transe,e − D≤ oe− oe<0
,Here, trans
e,e representsthe minimum transfertime, andmaxtrans representsthe maximumtransfer time that a passenger
wouldliketospendatastation.Weassumethatmax
trans≥ D>transe,e .Adistrans,1 andA dis,2
trans arebothrelatedtoEtransar ,whileAdistrans,3,
Atransdis,4 andAtransdis,5 areallrelatedtoEdis
ar.UndisruptedtransferactivitiesarethendefinedasAundistrans =A plan trans
\
(
Aplan
trans∩Adistrans
)
.5. Passenger-orientedtimetablereschedulingmodel
Inthissection,weformulatethepassenger-orientedtimetablereschedulingproblemasanMILPmodel,withthe objec-tiveofminimizinggeneralizedtraveltimes.TheMILPmodelconsistsofthreeconstraintmodules:1)timetablerescheduling, 2)dynamicevent-activitynetworkformulation,and3)passengerreassignment.
Thetimetablereschedulingmodulecomputesafeasiblerescheduledtimetable.Thedynamicevent-activitynetwork for-mulationmoduleformulatesanevent-activitynetwork
discorresponding totherescheduledtimetablebasedonthe pre-constructedtransitionnetwork
∗.Thepassengerreassignmentmoduledecidestheweightofeachactivitya∈
∗perceived
byeachpassenger,andassignseachpassengertothepathwiththeshortestgeneralizedtraveltimeperceivedbythis pas-senger.
The constraints used in the timetable rescheduling module are all from Zhu and Goverde (2019c) so that we do not presentthem in thispaper, neither the decision variables that are only used in thismodule. We refer to Zhu and Goverde(2019c)fordetails.Inthispaper,wepresenttheconstraintsinthemodulesofthedynamicevent-activitynetwork formulationandthe passenger reassignment,aswell asthe corresponding decisionvariables. Table3 liststhesedecision variables andthe modules inwhich they are used.The notationof parameters/setscan be found inTable 19in the Ap-pendix.Notethattherescheduledtimexeofanyeventethatwasoriginallyscheduledtooccurbeforetstartoraftertend+R
isforcedtobethesameasitsoriginalscheduledtimeoebyconstraintsfromZhuandGoverde(2019c).Inotherwords,our
modelrespectswhathasalreadyhappenedbeforethebeginningofthedisruption,andrecoversthedisruptionbacktothe normalscheduleatlatestRtimeaftertheendofthedisruption.
Duetoflexible stopping,scheduledstopscouldbe skippedandextrastopscould beadded.The scheduledstops (non-stops) can alsobe cancelled,dueto short-turningor completetrain cancellation. Table show all possiblestop types ina rescheduledtimetable,andthecorrespondingvaluesoftherelevantdecisionvariables.Therearespecificconstraintsinthe
timetablereschedulingmoduletolimit thevalue combinationsofce,ce andsa.We referto ZhuandGoverde(2019c)for
details.
5.1. Dynamicevent-activitynetworkformulation
The dynamic event-activity network formulation module decides which events and activities of the transition net-work
∗ areeffectiveinan event-activitynetwork
dis corresponding toa rescheduledtimetableby respectingtherules
of constructing an event-activity network introduced in Section 3. Recall that
∗=
(
E∗,A∗)
, where E∗=Earplan∪Eplande ∪Edde∗ ∪Eentryplan ∪Eexitplan∪Epenalplan, andA∗=Aplanrun ∪Aplandwell∪A plan
pass∪A∗wait∪A∗trans∪A∗board∪A∗entry∪A∗exit∪A plan
enpenal∪A
plan
expenal. In
partic-ular,Aplani =Aundis
i ∪A
dis
i ,i∈
{
run,dwell,pass}
,andA∗j=Aundisj ∪A disj ,j∈
{
wait,trans,board,entry,exit}
,whichmeansthatinthetransitionnetwork
∗, eachkind ofactivityset consistsoftwo subsets:an undisrupted activity set,anda disrupted activityset.Foranundisrupted activity,bothofthecorrespondingeventswillnot bedelayed/cancelledbythedisruption; whileforadisruptionactivity,atleastoneofthecorrespondingeventscouldbedelayed/cancelledbythedisruption.
5.1.1. Decidingwhicheventsareeffectivein
dis
The binarycancellation decision ce of an event e∈Earplan∪Edeplan∪Edde∗ is equivalent to deciding whether thisevent is
effectivein
dis.Anevente∈Eplanar ∪Edeplan∪Edde∗ iseffectivein
disifitisnotcancelled,ce=0.Thecancellationdecisionce
andtherescheduledtimexeofanarrival(departure)evente∈Earplan
(
e∈Edeplan)
aredeterminedinthetimetablereschedulingmodule.Aduplicatedepartureevente∈Edde∗ isrequiredtobecancelled/keptsimultaneouslyasitscorrespondingdeparture evente∈Edeplan,andtherescheduledtimesofbotheventsareforcedtobethesame:
ce=ce, e∈Edde∗ ,e∈E plan de ,
λ
e=e, (1) xe=xe, e∈Edde∗ ,e∈E plan de ,λ
e=e, (2)where
λ
e isagivenattributeindicatingthedepartureeventcorrespondingtoduplicatedepartureevente. Anevente∈Eplanentry∪Eexitplan∪Epenalplan isalwayseffectiveinanydis.
5.1.2. Decidingwhichactivitiesarealwayseffectiveinany
dis
Entry/exitpenaltyactivities,andundisruptedactivitiesareeffectiveinany
dis:
ya=1, a∈Aplanenpenal∪Aplanexpenal, (3)
ya=1, a∈
Aundisk
k∈K,K=
{
run,dwell,pass,wait,trans,board,entry,exit}
, (4)whereyaisabinaryvariablewithvalue1indicatingthatactivityaiseffectivein
dis,and0otherwise.Recallthatbothof
theeventscorrespondingtoanundisruptedactivitywillnotbedelayed/cancelledduetothedisruption.
5.1.3. Decidingwhichdisruptedrunactivitiesareeffectivein
dis
Recall that a running activityis froma departure event eto an arrival event e, which correspondto the same train atneighbouring stations. Adisrupted runningactivity in thetransition network
∗ will be effective inan event-activity network
disifneitherofthecorrespondingeventsiscancelled:
ya=1− ce, a=
(
e,e)
∈Adisrun, (5)ya=1− ce, a=
(
e,e)
∈Adisrun. (6)Notethat inthetimetablereschedulingmodule(ZhuandGoverde,2019c), thedeparture eventeandthearrival evente
inthesamerunningactivityare forcedtobe cancelled/keptsimultaneously: ce = ce,whichiswhywe useequalitiesfor
(5)and(6).
5.1.4. Decidingwhichdisrupteddwell/pass-throughactivitiesareeffectivein
dis
Recallthat a dwell(pass-through)activityis fromanarrival eventeto adeparture evente, whichcorrespondto the sametrainatthesamestation.Wedecidewhetheradisrupteddwell(pass-through)activityof
∗willbeeffectivein
dis
by:
ya≤ 1− ce, a=
(
e,e)
∈Adisdwell∪Adispass, (7)ya≤ 1− ce, a=
(
e,e)
∈Adisdwell∪Adispass, (8)ya≥ 1− ce− ce, a=
(
e,e)
∈Adisdwell∪Adispass. (9)Constraints(7)and(8)meanthatadisrupteddwell(pass-through)activitywillnotbeeffectivein
disifatleastoneofthe
correspondingeventsiscancelled;otherwise,itmustbeeffective(9).RecallthatAdis
dwell⊆ A
plan
Table 4
The stop type of activity a = (e, e ) ∈ A plan
dwell in a rescheduled timetable according to
c e , c e and s a . c e c e s a Stop type 0 0 0 Stop 0 0 1 Skipped stop 1 0 0 Cancelled stop 0 1 0 Cancelled stop 1 1 0 Cancelled stop Table 5
The stop type of activity a = (e, e ) ∈ A plan
pass in a rescheduled timetable according to
c e , c e and s a . c e c e s a Stop type 0 0 0 Extra stop 0 0 1 Non-stop 1 0 1 Cancelled non-stop 0 1 1 Cancelled non-stop 1 1 1 Cancelled non-stop
5.1.5. Decidingwhichdisruptedentryactivitiesareeffectivein
dis
Recall that an entryactivity isfroman entryeventetoa duplicatedeparture evente,which bothcorrespond tothe samestation.Weuseabinaryparameterre withvalue1toindicatethata(duplicate)departureeventecorrespondstoa trainorigindeparture,and0otherwise.Fora disruptedentryactivitya=
e,eofwhichtheduplicatedepartureeventecorrespondstoatrainorigindeparture,awillbeeffectivein
dis ifeisnotcancelled:
ya=1− ce, a=
(
e,e)
∈Adisentry,re=1. (10)Fora disrupted entryactivity a=
e,e ofwhich the duplicatedeparture event e doesnot correspond to a train origin departure,weestablishedthefollowingconstraintstodecidewhetheraiseffectiveindis:
ya≤ 1− ce, a=
(
e,e)
∈Adisentry,re=0, (11)ya≤ 1− sa+ce+ce, a=
(
e,e)
∈Adisentry,re=0,e=λ
e,a=(
e,e)
∈Adisdwell∪Adispass, (12)ya≥ 1− sa− ce− ce, a=
(
e,e)
∈Adisentry,re=0,e=λ
e,a=(
e,e)
∈Adisdwell∪Adispass. (13)Constraint(11) meansthat adisrupted entryactivitya=
(
e,e)
will notbe effectiveindis ifits correspondingduplicate
departureeventeiscancelled.Otherwise,awillbeeffectiveonlyifitscorrespondingduplicatedepartureeventeis asso-ciatedwitharealstopa=
(
e,e)
∈Adisdwell∪Adispass thathasce=0,ce=0andsa =0(seeTable4andTable5),inwhich
e
isthedepartureeventcorrespondingtoe:e=λ
e.Thisisrepresentedby(12)and(13).5.1.6. Decidingwhichdisruptedboardingactivitiesareeffectivein
dis
Recall that a boarding activity is from a duplicate departure event e to the corresponding departure event e. For a disruptedboarding activitya=
e,eofwhich theduplicate departureeventecorresponds toa trainorigindeparture, awillbeeffectivein
disifeisnotcancelled.:
ya=1− ce, a=
(
e,e)
∈Adisboard,re=1. (14)Foradisruptedboardingactivitya=
e,eofwhichtheduplicatedepartureeventedoesnot correspondtoatrainorigin departure,wedecidewhetheraiseffectiveindisby
ya≤ 1− ce, a=
(
e,e)
∈Adisboard,re=0, (15) ya≤ 1− sa+ce+ce, a=(
e,e)
∈Adisboard,re=0,a=(
e,e)
∈A dis dwell∪A dis pass, (16)ya≥ 1− sa− ce− ce, a=
(
e,e)
∈Adisboard,re=0,a=(
e,e)
∈Adisdwell∪Adispass. (17)Constraint(15)meansthatadisruptedboardingactivityawillnotbeeffectivein
disifitscorrespondingduplicate depar-tureeventeiscancelled.Otherwise,awillbeeffectiveonlyifitscorrespondingdepartureeventeisassociatedwithareal
stopa=
(
e,e)
∈Adis5.1.7. Decidingwhichdisruptedexitactivitiesareeffectivein
dis
Recallthatanexitactivityisfromanarrivaleventetoanexitevente,whichbothcorrespondtothesamestation.We useabinaryparameterfe withvalue1toindicatethat anarrival eventecorrespondsto atraindestinationarrival,and0
otherwise.Fora disruptedexitactivitya=
e,eofwhich thearrivaleventecorrespondstoa traindestinationarrival,awillbeeffectivein
dis ifeisnotcancelled:
ya=1− ce, a=
(
e,e)
∈Adisexit,fe=1. (18)Fora disruptedexitactivitya=
e,eofwhichthearrival evente doesnotcorrespond toatrain destinationarrival, we establishedthefollowingconstraintstodecidewhetheraiseffectiveindis:
ya≤ 1− ce, a=
(
e,e)
∈Adisexit,fe=0, (19)ya≤ 1− sa+ce+ce, a=
(
e,e)
∈Aexitdis,fe=0,a=(
e,e)
∈Adisdwell∪Adispass, (20)ya≥ 1− sa− ce− ce, a=
(
e,e)
∈Adisexit,fe=0,a=(
e,e)
∈Adisdwell∪Adispass, (21)Constraint(19)meansthatadisruptedexitactivitya=
(
e,e)
willnotbeeffectiveindisifitscorrespondingarrivalevente
iscancelled.Otherwise,awillbeeffectiveonlyifitscorrespondingarrivaleventeisassociatedwitharealstopa=
(
e,e)
∈Adis dwell∪A
dis
pass thathasce=0,ce=0andsa =0.Thisisstatedby(20)and(21).
5.1.8. Decidingwhichdisruptedwaitactivitiesareeffectivein
dis
Recallthatawaitactivityisfromaduplicatedepartureeventetothenexttime-closestduplicatedepartureeventethat occursatthesamestationbutcorresponds toa differenttrain.Wedecide whetheradisruptedwait activitya=
(
e,e)
is effectiveindisby ya≤ 1− ce, a=
(
e,e)
∈Adiswait, (22) ya≤ 1− ce, a=(
e,e)
∈Adiswait, (23) ya≤ 1− sa+ce+ce, a=(
e,e)
∈Adiswait,re=0,e=λ
e,a=(
e,e)
∈A dis dwell∪A dis pass, (24)ya≤ 1− sa+ce+ce, a=
(
e,e)
∈Adiswait,re=0,e=λ
e,a=(
e,e)
∈Adisdwell∪A dis pass, (25) ya+ya≤ 1, a=(
e,e)
∈Adiswait,a=(
e,e)
∈A dis wait (26) a∈Adis wait, tail(a)=e ya≤ 1, e∈Eddedis, (27) a∈Adis wait, head(a)=e ya≤ 1, e∈Edisdde, (28)xe− xe≤ M
(
1− ya)
, a=(
e,e)
∈Adiswait,a=(
e,e)
∈Adiswait, (29)xe− xe≤ M
(
1− ya)
, a=(
e,e)
∈Adiswait,a=(
e,e)
∈Adiswait, (30) xe− xe≥ −M(
1− ya)
, a=(
e,e)
∈Adiswait, (31)wheretail(a)referstothetaileventofanactivity:theeventwhichanactivitystartsfrom,head(a)referstotheheadevent ofanactivity:theeventwhichanactivitydirectsto,andMisasufficientlylargenumberofwhichthevalueissetto2880. Constraints(22)and(23)meanthatadisruptedwaitactivitywillnotbeeffectivein
disifatleastoneofthecorresponding eventsiscancelled.Constraint (24)(25)requiresa disruptedwaitactivity a=
(
e,e)
tobe ineffectiveifthecorresponding duplicatedeparture evente(e) doesnot correspondto atrain origindeparture andisnot associatedwitharealstop. A duplicatedepartureeventcouldberelevanttomultipledisruptedwaitactivitiesinatransitionnetwork,whileatmostone oftheseactivities canbeeffectiveinanevent-activitynetworkdis(26)–(28).Constraints(29)–(31)togetherensurethata duplicatedepartureeventecanonlybelinkedtothenexttime-closestduplicatedepartureeventtoconstructaneffective waitactivityin
dis.
5.1.9. Decidingwhichdisruptedtransferactivitiesareeffectivein
dis
Recallthatatransferactivityisfromanarrivaleventetothenexttime-closestduplicatedepartureevente thatoccurs atthesamestationasebutcorresponds toadifferenttrain.Wedecidewhetheradisruptedtransferactivitya=
(
e,e)
is effectiveindis by
ya≤ 1− ce, a=
(
e,e)
∈Adistrans, (32)ya≤ 1− ce, a=
(
e,e)
∈Adistrans, (33)ya≤ 1− sa+ce+ce, a=
(
e,e)
∈Atransdis ,fe=0,a=(
e,e)
∈Adisdwell∪Adispass, (34)ya≤ 1− sa+ce+ce, a=
(
e,e)
∈Adistrans,re=0,e=λ
e,a=(
e,e)
∈Adisdwell∪Adispass, (35)a∈Adis trans,
tail(a)=e
ya≤ 1, e∈Eartrans∪Edisar, (36)
xe− xe≤ M
(
1− ya)
, a=(
e,e)
∈Adistrans,a=(
e,e)
∈Adistrans, (37)xe− xe≤ M
(
1− ya)
, a=(
e,e)
∈Adistrans,a=(
e,e)
∈Adistrans, (38)xe− xe≥ −M
(
1− ya)
+transe,e , a=(
e,e)
∈Adistrans, (39)where trans
e,e refers tothe minimumtransfer time. Constraints (32)and(33)means that a disruptedtransfer activitywill
notbeeffectivein
disifatleastoneofthecorrespondingeventsiscancelled.Constraint(34)requiresadisruptedtransfer
activity a=
(
e,e)
to be ineffectiveif thecorresponding arrival eventedoes not correspondto a train destination arrival andisnotassociatedwitharealstop.Constraint(35)requiresadisruptedtransferactivitya=(
e,e)
tobeineffectiveifthe correspondingduplicatedepartureeventedoesnotcorrespondtoatrainorigindepartureandisnotassociatedwithareal stop.Constraint(36)meansthatforanarrivalevente∈Etransar ∪Eardis,whichhasmultipledisruptedtransferactivitiesstarting
fromit, atmostone oftheseactivities will be effectiveinan event-activity network
dis.Constraints (37)–(39) together ensurethatanarrivaleventecanonlybelinkedtothenexttime-closestduplicatedepartureeventtoconstructaneffective transferactivityofwhichtheminimumtransfertimemustberespected.
5.2. Passengerreassignment
Therecould bemultiplepassengers whoshareexactlythesamejourneysintermsoftheplannedtimetable:thesame originstation,thesamearrival timeattheoriginstation,thesamedestination,andthesameexpectedgeneralizedtravel time fromtheoriginto thedestination. Thesepassengers formasame groupg ∈G,whichis assumedtobe inseparable incaseofa disruption,andwillnot changethedestination.Grepresents thesetofpassengergroups, possibly consisting of a singlepassenger. Recall that a path is a sequence ofconnected activities. Decidingwhich path will be chosen by a passenger groupis equivalentto decidingwhich activities willbe chosen bythisgroup, whileeach groupg isassociated withthesameactivitychoicesetA∗.Thepassengerreassignmentmoduledecideswhichactivitya∈A∗willbechosenbya passengergroupgandtheweightofeachactivitya∈A∗perceivedbyg.
5.2.1. Assigningeachpassengergrouptoonepathonly
Anactivitya∈A∗cannotbechosenbyapassengergroupifaisnoteffectivein
dis(ya=0):
uga≤ ya, a∈A∗,g∈G, (40)
where uga is a binarydecision with value 1 indicating that activity a ∈A∗ is chosen by passenger group g ∈ G, and 0 otherwise.
A path that could be chosen by a passenger group g must start from an entry (entry penalty) event corresponding to his/heroriginOg, endinan exit(exitpenalty) eventcorrespondingto his/herdestination Dg,andincludeatleastone
intermediateeventtoconnectthem:
a∈Aundis entry∪Adisentry∪A
plan enpenal, sttail(a)=Og uga=1, g∈G, (41) a∈Aundis entry∪Adisentry∪A
plan enpenal,
sttail(a)=Og