The processes used to support transport related decision-making, fall into two main categories, namely: 'strategic assessment’ and 'detailed evaluation’.
 
Detailed Evaluation

Detailed evaluation represents a detailed pre-investment scrutiny of proposals. This is an important process and usually includes operational factors, (travel time, vehicle costs and safety). Detailed evaluation can also take account of detailed (monetised and non-monetised) environmental, social and economic aspects.

Detailed evaluation methods are most effective if they are  consistent with strategic assessment methods and used for  selecting proposals for implementation purposes.

Cost benefit analysis is often used as a component of detailed evaluation to compare costs and monetised benefits and is typically applied to packages and proposals (see also separate web page on cost benefit analysis)

Scenario testing

Future transport system conditions can be considered when  evaluation is undertaken. For example, if it is thought that pricing arrangements may change in the future, this can be allowed for in evaluation methodologies.