Airport link specialist BrisConnections Management Company Ltd (ASX: BCSCA) said on Friday that construction of the $5.6 billion Brisbane road project is more than fifty percent complete though it added that the company posted a much lower profit for the current full year.

The company said that as of June 30 this year, it has netted $17.16 million, a slide of 29.6 percent from figures registered in the previous year, which it said were results reflective of considerable advancement so far made on its Brisbane road project.

BrisConnections chair Trevor Rowe said that the Airport Link, currently the biggest privately-funded road infrastructure project in Australia, should be completed in time and still adheres to the working budget.

Mr Rowe said that Brisbane Airport Link construction has so far achieved significant progress and should meet its targeted commencement of operations as he stressed that "the board of BrisConnections remains confident that, at the current rate of progress, Airport Link will be operational by its due delivery date of mid-2012."

The company said that by the last financial year, the road's construction was able to build a tunnel 22 metres below ground while both tunnel-boring machines were already started.

Mr Rowe said that the project had already passed the halfway mark in construction cost and time table, with total funding now running to more than $1.275 billion as he stressed that refinancing would not be required until 2018.