Economic analysis is perhaps the key operational analysis function that can be undertaken by TMfS. In the UK, considerable emphasis is placed on undertaking a thorough evaluation of a scheme before its construction is committed.

The Road and Public Transport Assignment Models can provide the relevant inputs required to undertake cost benefit analysis and subsequent preparation of Transport Economic Efficiency tables (TEE tables), a key part of any economic assessment undertaken using the Scottish Transport Appraisal Guidance (STAG) framework. At present, the recommended software for undertaking further economic analysis of the model outputs is TUBA, the Department for Transport’s software package for assessing the economic case for a scheme. In conjunction with operational analysis, toll revenues can also be calculated.

An economic assessment of a transport scheme involves identifying all of the costs and all of the benefits and comparing them to establish a cost-benefit ratio. However, economic assessments include both monetary (such as fuel and car maintenance costs) and non monetary (time, life and the environment) costs and benefits - this type of analysis is known as social cost-benefit analysis (SCBA).

TUBA will assess the social cost-benefit ratio of a transport intervention over a 60 year time horizon, drawing in both the monetary and social costs and benefits and discounting them to current values. It will provide a social-cost benefit ratio for each package of interventions and will highlight the most valuable package.