The identification of problems and opportunities within the transport and land-use system under consideration must form the basis of the development of a STAG transport study.
The process of defining objectives, described in Section 3, and the identification of problems and opportunities, the subject of this section, are parallel and iterative processes. An initial assessment of problems and opportunities should inform Objective Setting, which in turn may highlight the need for further investigation of problems and opportunities.
It is essential that consideration is given to existing and future problems and opportunities that may potentially arise. Similarly, those perceived by stakeholders should also form a thorough part of this assessment during Pre-Appraisal.
The identification of opportunities is often given insufficient attention during a STAG study and it should be recognised that this is an equally important task to be completed during the Pre-Appraisal process. As such, opportunity analysis should be given appropriate and explicit attention during Pre-Appraisal.
The problem identification stage should not be limited to just the identification of problems that can be quantified through the analysis of data or the use of a transport model. It should also consider "perceived problems", that is problems that are experienced but cannot be easily encapsulated through data analysis. Consultation with stakeholders and the public can provide a valuable input into the problem identification process.
The problem identification process should look beyond their immediate manifestation on the transport system and should explore their root causes and consequences.
Existing or new data can assist in the identification of problems and guidance is given on which data may be helpful and how it can be used. Transport models are also a potential source for analysis of existing and potential problems, but models must be treated with caution. Their contribution is limited to the modes and interactions that are modelled and this may not cover the full set of problems pertinent to a study.
Each model is underpinned by a set of implicit and explicit assumptions that will influence any assessment of problems. Such assumptions will need to be understood and considered.
When considering problems it will also be important for the practitioner to consider issues and constraints that face the study. ‘Issues' are uncertainties that the study may not be in a position to resolve, but must work within the context of. ‘Constraints' are the bounds within which a study is being undertaken.
The Scottish Government and/or Transport Scotland requires a textual statement of the problems, issues and constraints along with the appraisal to accompany each submission.
