As discussed above, in both the scoping (Part 1 AST) and detailed (Part 2 AST) appraisals, it is necessary to consider:
In undertaking this analysis, it is necessary to consider how the transport option potentially affects economic activity, first at a local level and then at the Scotland level. It is then necessary to undertake research on this at a level commensurate with the size of the transport option and the significance of potential EALIs as part of the case for that option. Guidance on practical approaches is given below in the section on the Part 2 AST and in the section on further technical guidance.
First, however, it may be useful to illustrate the point regarding gross and net impacts using the above example of a ferry service. Tourist visitors to that island who would come even without the improved service gain through improved accessibility, but this may have little overall impact for the island as a whole, but time savings might translate into re-distributing visits to more remote parts of the island.
In addition, improved access could also lead to more people travelling to that island and hence more tourist bed-nights, which generate both an output and employment impact at the level of that particular island. Here there could be both positive and negative gross impacts; there could for example be a negative impact from loss of expenditure by tourists who decide not to come if the island is perceived to have become "crowded", but a larger positive impact arising through a larger increase in new visitors who would not have come had the ferry not been improved.
However, where the extra travellers would have come to Scotland regardless of the improved ferry service, the impact of the service for these visitors is to re-distribute their travel and associated expenditure to the island with the improved ferry service at the expense of other areas.
Thus the impact at the island level may be positive, and within the island there may also be redistribution benefits, but at the Scotland level the net impact is likely to be zero, as the additional expenditure on the island will almost certainly be at the expense of places elsewhere in Scotland. If a case were made for a positive (or negative) net impact, convincing evidence would be required to justify such a case.
