Scotland's 30-plus air quality management areas could be the next UK adopters of workplace parking levies to deter car commuting, after Nottingham in 2012.
The anti-congestion alternative to road charging appears as a topic 'worth further investigation' in the Scottish Government's November 2015 Cleaner Air for Scotland' strategy document.
This aims to fast-track the reductions in air pollution needed to meet legal EU requirements 'as soon as possible'.
Meanwhile, road charging itself is nowhere on the Scottish Government's political agenda, Transport Scotland's head of environment and sustainability, Dr Stephen Thomson, told ITS(UK)'s 2015 Smart Environment Interest Group Conference last week.
Scottish ministers are unmoved by the Institution of Civil Engineers Scotland's call, earlier this month, for a 'serious exploration' of direct charging to meet the 'financial demands' of constructing and maintaining good quality roads infrastructure.
Earlier policy in the country's National Transport Strategy, a 'refreshment' of which is due for completion by end-2015, committed the Scottish Executive to exploring road pricing as a 'mechanism to address traffic impacts'.
It envisaged working with local authorities on a pilot in a 'medium sized urban area' and carrying out technical studies at pinch points and along problem corridors in order to assess the appropriateness of introducing pricing.