Solving themobilemappingvanproblem:Ahybridmetaheuristicforcapacitated arc routingwithsofttimewindows

Creating digitalmapsoftenrequiresdrivingaroundthestreetsinaso-called“mappingvan”.TeleAtlas, the worldleadingsupplierofmapsandmapdata,usesafleetofsuchvehiclestotakepicturesofstreets and roadsigns.Minimisingthenumberofdaysthatavehicleneedstotraverseallstreetsinagiven region givesrisetoacapacitatedarcroutingproblem.Aspecificcharacteristicofthisproblem,however, is thefactthattakingpicturesinthedirectionofthesunshouldbeavoidedasmuchaspossible.This requirement addssofttimewindowstotheproblem. In thispaperwesolvethemobilemappingvanproblembytransformingitintoavehicleroutingproblem with softtimewindows.Wethenapplyahybridmetaheuristic,consistingofalocalsearchphaseto decrease thenumberofdaysandaniteratedlocalsearchphasetominimisethetimewindowviolations. An exactlinearprogrammingsolverisembeddedtocalculatetheidealstartingtimeofthevehiclein each street. Our methodistestedonacademicandreal-lifeprobleminstancesandshowntobeeffective.