Why the Pacific Hwy is missing out on millions

A NEW economic breakdown of national roads funding has found governments are overspending on marginal areas to gain votes.

But the Grattan Institute research deemed the North Coast's Pacific Hwy upgrades overdue, not overblown.

In fact, the overall safety quality of the link between Sydney and Brisbane - even after $7.8 billion in upgrades - was found to be lower than many other roads with significantly less traffic.

Grattan Institute transport program director Marion Terrill said the study revealed roads in electorates where federal elections were won and lost received big spending, even if they had little economic significance.

The New England Hwy had received $2.1 billion in New South Wales and Queensland government funding, equating to 9% of all national road network funding outside the capital cities, despite carrying only 5% of the traffic.

Over the past decade, more was spent per vehicle kilometre on the New England Hwy than the far more heavily used Pacific Hwy, even though the latter was the most heavily used highway in Australia and provided a shorter and faster route between Sydney and Brisbane.

Much of the New England Hwy runs through the New England seat - an electorate formerly held by independent Tony Windsor, who has vowed a return to politics to challenge Deputy Prime Minister Barnaby Joyce at the upcoming election.

It became a major focus of government attention in 2010-13, when Mr Windsor was one of six crossbenchers holding the balance of power.

"One difficulty is that there is little to prevent politicians committing to projects on the basis of weak or undisclosed business cases - and particularly during election campaigns," Grattan Transport Program director Marion Terrill said.

"There isn't enough publicly available information on potential projects, so the public can't hold politicians to account or be confident that funds are spent wisely."

>> RELATED: Seven Pacific Highway hotspots that continue to frustrate motorists