The discussions over who pays for roads, and infrastructure more generally, is not going to go away (in Scotland or across the whole of the UK).

The Chancellor is promising continued investment and he will no doubt reiterate this in the forthcoming Spending Review / Autumn Statement on 25 November. However, innovative ways of funding new projects do not appear to be off the agenda. Tolls are one possible way but there are other charging mechanisms in place. Charges are also used for other public policy needs as well - the congestion charge in London, low emissions zones and workplace parking levies being just three.

The Government is also facing a fall off in revenue from fuel duty as vehicles get more efficient and people take up public transport options as well.

The Department for Transport often looks at radical solutions to help deal with these issues - from privatisation through to charging or tolling of the motorways.

No politician has yet been brave enough but if there is a real shortfall....