A refreshed version of Scottish Transport Appraisal Guidance has been published on 28May 2008, which supersedes the previous version. Stewart Stevenson MSP, Minister for Transport, Infrastructure and Climate Change stated:

"Scottish Transport Appraisal Guidance supports the Government's Purpose and National Outcomes by assessing what contribution can be made by potential transport interventions."

"The Guidance was first published in September 2003. I commend this refreshed version to you, reflecting feedback from a range of transport practitioners and decision makers."

"I expect this Guidance to be followed by all those wanting to invest in transport, whether that is the Scottish Government itself, Regional Transport Partnerships, Local Authorities, private companies or others. In particular, the objective led framework recommended here is seen as best practice in transport appraisal internationally. Following these principles, as set out in the Guidance, will ensure that the best solutions to transport problems or opportunities to make transport improvements are taken forward, based on robust evidence."

It should be noted that the principles of undertaking appropriate transport appraisal using Scottish Transport Appraisal Guidance (STAG) have not changed in terms of being objective-led. Importantly, however, the opportunity has been taken to refresh STAG for the following reasons:

To clearly establish that it supports the Government's Purpose, which is to focus the Government and public services on creating a more successful country, with opportunities for all of Scotland to flourish, through increasing sustainable economic growth.

To make it fit for purpose, including reflecting feedback from stakeholders from consultation undertaken in 2006 and 2007, so that STAG studies are carried out in proportion to the evidenced based transport problems and opportunities being addressed.

To make it easier to follow. STAG now consists of a compressed version of the Guidance, which explains the purpose of the process, and this is supported by a Technical Database, which provides details on how to undertake an appraisal using STAG. To improve clarity on undertaking appropriate appraisal and reporting.

To highlight that an appraisal using STAG should be completed before commencing detailed design elements using mode specific guidance or standards and/ or before undertaking a development management Transport Assessment. To re-emphasis that STAG is a whole process inclusive of Monitoring and Evaluation. To stress that it is the responsibility of any party undertaking a STAG study to check at key points that the process is being followed as intended.

The publication of the refreshed version of STAG has also provided an opportunity to update and augment some aspects of the material that now rests in the Technical Database. These 'Business as Usual' updates include:

The Monetisation of carbon - in line with UK guidance on climate change, the value of all carbon emissions must now be reported. The introduction of Wider Economic Benefits - new guidance has been introduced on how to capture the impacts of transport schemes on economic output and productivity.

Guidance on the application of Optimism Bias - this provides clear guidance on the treatment of risk and uncertainty. Optimism Bias should now be applied to both capital costs and risk assessment, meaning that there is no need for a contingency allowance.

Changes to reporting indicators - a new summary table has been introduced, which summarises an option's impact against all the STAG Criteria and the Government's Purpose. New indicators have also been introduced for each criterion which reports monetary impacts, but the BCR and NPV remain the key indicators.