$[$Start$]($Commuter: Start Purchase$)($TVM: Request Trip Info$)($Commuter: Enter Trip Details$)($TVM: Calculate Payment$)($TVM: Display Payment Options$)[$Cash$?$ or Card?$]$Cash$($Insert Cash$)[$Sufficient$?]($Process Cash$)($Issue Ticket$)[$End$]$Card$($Enter Card$)($TVM: Request Bank Auth$)($Bank: Process Payment$)[$Approved$?]$Yes$($Issue Ticket$)[$End$]$No$($Notify Failure$)[$Retry$/$Cancel$]$Retry$$ Loop to Enter Card $$Cancel$[$End $($Failure$)]$