The Northern Territory Government has admitted that taxpayers will have to pay the cost of fixing a badly designed road to the new Darwin prison at Holtze.
The road has been the subject of questions at Territory budget estimates hearings.
Independent Gerry Wood questioned why it needed to be re-routed soon after it was built.
"What is the cost of this extra work and who is paying for it?" he asked.
Department of Lands and Planning chief executive David Richie says the initial design could not cope with the heavy triple and quad-trailer trucks that use the road and the government had to start again.
"The responsibility for that is ours, and hence mine, and that cost is about $120,000, which will be borne by the project," he said.
The Government also revealed the final cost of the extension of Tiger Brennan Drive, a joint Commonwealth and Territory road project.
Mr Wood was told the budget for the project was $110 million but it had finally cost $127 million.
Director of Roads Ernie Wanka says some of the $17 million over-run could be explained by material costs that had increased over the life of the project, as had the scale of the works.