Security concerns are high on the political agenda in many countries because of the
widespread perception that security is increasingly threatened by intentional malicious acts
including terrorist attacks. While terrorism has a long history and measures to maintain and
improve security are in place, major events – including but not limited to the 9/11 attacks –
have triggered stronger action to improve security. In this context, much attention goes to
maintaining secure transport for two reasons. First, many transport facilities and vehicles are
appealing targets for terrorist attacks because of the concentration of potential victims.
Second, transport can act as a conveyor for terrorist attacks, e.g. by moving weapons into
ports or by turning airplanes into weapons. In both cases, the difficulties in protecting the
many potential targets while maintaining smooth transport operations strengthens the appeal of transport targets.
