The risk register (see Table 1) used in for the
survey was prepared based on extended literature review (Roumboutsos et al, 2012) and risks
were represented as with respect to their key project phase of occurrence. Risks that could
demonstrate at any time were considered “life cycle risks”. In addition, some risks were
further detailed, expressing the need to differentiate the initial source. Such is the case of the
“demand risk”, which is at the heart of transport PPPs, as follows: