While the cost of the new Forth crossing has soared and Glasgow's Clyde Arc "squinty bridge" remains closed after a section fell off, a landmark footbridge over the M8 is now running late and over budget.
The cost of the new crossing at Harthill, midway between Edinburgh and Glasgow, has risen by nearly a quarter to 5.1 million.
The project, which should have been finished last autumn, will be ready a year late, the Scottish Government's Transport Scotland agency has admitted.
The news came as Stewart Stevenson, the transport minister, prepared to launch work on the scheme today.
The futuristic glass and steel design will replace a 40-year-old bridge built as part of Scotland's first motorway services.
The rest of the service area has been replaced with a filling station, shop and caf either side of the motorway.
However, a bridge is required for the 500 passengers a day who use Harthill to connect between Edinburgh-Glasgow coaches and local buses. It is also used by cyclists.
The new 210ft span will comprise a helical lattice truss, made of tubular steel, encasing a fully-enclosed glazed walkway.
When the bridge design was announced by Tavish Scott, the last transport minister, in August 2006, Transport Scotland said the replacement would be in place "by autumn 2007" and cost 4.1 million. Work was expected to start in spring 2007.
However, Transport Scotland said yesterday the cost had increased by 1 million because old mineworkings had to be made safe, and construction industry prices had increased.
The current bridge was built following completion of the Harthill bypass, the first section of the M8, in 1965. Transport Scotland said it was now in poor condition.
The agency said the M8 would be closed for three weekends between junctions four and five.
A spokeswoman for Transport Scotland said: "The discovery of a previously unknown, untreated, mineshaft impacted on costs and delivery times.
"The conceptual design was also enhanced and developed with improved inclusive access," she said.