[2][3] Its development reflected the new Labour Government's aim of providing a more balanced approach to transport appraisals, in terms of both: Accompanying documents to that review list the ASTs for 68 trunk road schemes and provided initial guidance on how NATA was to be applied to transport projects.
A key aspect of NATA is the use of standard worksheets to collate the large amount of cost–benefit analysis and environmental impact assessment data and then present it in a more concise, consistent and balanced way.
The division of the five criteria is shown below: The NATA framework is now a cornerstone of UK transport appraisal practice.
However the NATA approach raises issues regarding the precise definition of the impacts that are included in the numerator and denominator of the Benefit-Cost Ratio.
[1] The appraisal procedure used by the Roads Service in Northern Ireland's Department for Regional Development is based on the five NATA criteria.