Is M74 extension project early and under budget?
The opening of the M74 extension is being hailed as a triumph for the Scottish government and taxpayers. But has the project been delivered ahead of schedule and under budget?
Scotland's politicians have learned the hard way that the public is unlikely to trust any promise to deliver a major transport project "on time and on budget".
The Edinburgh trams fiasco has seen to that. Soaring costs and ever-increasing delays have undermined public confidence to such an extent that taxpayers could be forgiven for wondering how the country which built the Forth Bridge could have lost its way so badly.
That may explain why Scottish government ministers are keen to remind us the M74 extension has actually been completed ahead of schedule and under budget.
The construction of the new motorway was expected to cost £445m. Now, we are told, the final price tag could be as low as £437m.
The Cabinet Secretary for Infrastructure and Capital Investment, Alex Neil, described that as "clear evidence" of the Scottish government's "robust and effective management of major projects".
But the total price of the M74 extension is much higher than the headline figure suggests.
The national transport agency, Transport Scotland, originally estimated the total cost would be £692m. The figure is higher because of the cost of purchasing the land required for the route.
The savings made during construction mean Transport Scotland is likely to complete the project for less than its own original estimate.
We should have the final figure in the autumn.
So why do opponents of the project argue it is wrong to claim the work has been completed under budget and ahead of schedule?
That argument is based on figures given to the Scottish Parliament a decade ago by the then Labour transport minister, Sarah Boyack.
She told MSPs the cost of building the road would be only £245m and work would be completed by 2008.
Transport Scotland says it is misleading to use those figures as a baseline because the project then was promoted by Glasgow City Council, rather than the Scottish Executive. The estimates then were at May 2000 prices and made no provision for risk or inflation.
Of course, arguments over the cost of this scheme are only part of the story.
The M74 project has been controversial from the outset. Indeed, work only began after Scottish ministers dismissed the findings of a local public inquiry which found the motorway was "very likely to have very serious undesirable results".
Certainly, environmentalists and people living along the route of the new motorway have never been convinced.
Stan Blackley, the chief executive of Friends of the Earth Scotland, said: "This road will fill up with traffic, it will create more pollution and it will disenfranchise more people in poorer communities."
But business leaders are adamant that anything which helps get Glasgow's traffic moving more smoothly must be good news for the whole of the Scottish economy.
The M74 extension may be complete but the arguments over the true financial and environmental costs of the project are far from over.