In this section, problems are effectively the genesis of an option and are measurable through shortfalls in meeting the objectives. For example, rapid traffic growth in recent years would be a problem if it were acting against an objective to improve local air quality or were causing congestion that was seen to be suppressing economic growth. In contrast, if traffic growth could be accommodated on the network it need not be a (local) problem.
Problems with the transport system can be experienced by its users as well as third parties who are impacted upon by the use of the system.
It is important to recognise that perceptions of problems with the transport system by users, operators, the public at large and politicians can be equally as important as problems that can be quantified through analysis of data. Such problems are called perceived problems in the text although this should not be taken to have any pejorative meaning; just because a problem is perceived and cannot be easily quantified does not mean that it has no basis and should not be addressed. Indeed, the analyst should strive to capture the perceived problems as thoroughly as possible. There will be, however, cases where perception of a problem is misplaced; the onus is then on the practitioner to explore such problems and explain the real root cause of any shortfall in meeting objectives.
Constraints and uncertainties are matters that a study will have to consider when developing an option, but are largely outwith the immediate influence of the study.
