As shown in many chapters of this book, transport plays a crucial role in modern societies. A well-functioning maritime transportation system facilitates the process of globalisation and ongoing economic growth; it is a motor for economic processes. Also the port-cities benefit directly, not only in terms of employment and well-developed infrastructures, but also with respect to related service industries and so forth. In the EU-28, these activities represent about 10% of the employment, but for Singapore and Shanghai this is even above 20%. This explains why the transport sector, for more than a century now, has experienced unprecedented growth. At the same time, transport has undesired side effects. We see that the maritime transport sector (including ports activities and hinterland connectivity) is increasingly associated with negative feelings: there are serious concerns related to emissions (at the regional, national and global levels), safety, public health issues and so forth. To illustrate: more than half of the SO2-emissions in Hong Kong are ship related, about 85% of all truck traffic on certain highway sections in Los Angeles is port related, the port area in Antwerp encompasses one-third of the city’s land mass and so forth. All these concerns are encompassed in the concepts of sustainability. To improve the environmental performance of shipping, port activities and hinterland transportation, and to fulfil environmental standards are nowadays preconditions to operate.