The work on the Cotter Road between Streeton Drive and the Tuggeranong Parkway is being undertaken to provide better road for the area's new Molonglo Valley suburbs.

But local driver, and two-time Liberal party election candidate Ron Forrester, of Duffy, is not happy with the duration of the job or the expense.

''We are talking about 800 metres of road,'' Mr Forrester wrote in The Canberra Times.

''Imagine my amazement, when I discover that we taxpayers have been made to pay $14 million, so far, for this 800 metres.

''How is this possible?

''Shame on the ACT government.''

Acting on Mr Forrester's complaint's, The Canberra Times asked Economic Development Directorate director-general David Dawes why the job had taken so long and cost so much.

Mr Dawes said the project was complex because cars and other vehicles continued to use the road while the work was in progress.

''We said that the job would be done in September or October and that might slide by a month so the project hasn't gone too badly,'' the director-general said.

''It's important to remember that if you've got a greenfield site, you've got a bit more open slather because, while occupational health and safety is still very important, you're not as concerned about existing residents or motorists.

''That's why we've got all the safety barriers and other things there.

''There's a big difference when it comes to building in an urban environment to working in a greenfield situation and that obviously comes with a bit of a premium on it.''

The job had the added complications of moving vital service infrastructure that was buried beneath Cotter Road, according to Mr Dawes. ''When you're building in this environment, there's a whole lot of service underground and we've had to move those even though there's only 800 metres of road there,'' he said.

''For example, there's a fibre optic cable there and it's not just a matter of moving just one or two metres, we've had to move 1.8 kilometres of fibre optic cable, and we've moved it much further, so we can plan for things that might happen down the track.

''There was an existing 300 millimetre water main there that we've had to relocate too and you don't pick up those and move them just a metre or two, you just don't move 800 metres of pipeline easily,'' he said.