20thcentury 21stcentury buses business buslines economicaspects electricutilities emergencymanagement europe hijackingofships history identification infrastructure(economics) international internationaltrade legaldocuments localtransit localtransitcrime merchantmarine northernireland passports prevention railroads safetymeasures seacontrol security securitymeasures shipping terrorism tourism transportation unitedstates vandalism weaponsofmassdestruction worldpolitics