HALIFAX -- Nova Scotia taxpayers could be on the hook for more than $2 billion in initial construction costs if the province decides to twin 300 kilometres of highway, according to the preliminary findings of a feasibility study.

The study released Thursday by Halifax-based engineering firm CBCL Ltd., ranks the feasibility of twinning each of eight sections of 100-series highways identified by the province, including some of the most dangerous stretches of road in Nova Scotia.

The rankings are based on six criteria, including safety, costs versus the projected revenues from tolls, and traffic volumes.

"Safety and cost were weighted the highest with equal priority, as we needed to consider the revenue to be able to fund construction of the twinned highways," said Audrey Muir, project manager for CBCL.

A section of Highway 103 between Tantallon and Bridgewater is top of the list, followed by a section of Highway 101 from Windsor running west.

"The cost estimates range from approximately $60 million for the shortest section to $442 million for the longest corridor," said Muir. "This is not an insignificant undertaking for the province."

Currently, the provincial government spends about $420 million each year to build and maintain roads.

The study used benchmark toll amounts of six to 10 cents per kilometre based on the results of a "willingness to pay" study, and then calculated revenue projections for each section of highway.

Muir said Highway 103 had the highest revenue projections in part due to its 68-kilometre length and its higher volumes of traffic compared to some of the other corridors.

Transportation Minister Geoff MacLellan said there's been no decision to move ahead with twinning based on tolls.

He said it would take years to tackle the ambitious project and added the province simply doesn't have the money to do it as fast the public wants without tolls.

"This does become about the financial structure, no doubt about it," he said.

MacLellan said a decision on tolls would only come after consultation with the public and further data from CBCL in the final phase of its study.

There are no timelines for either at this point.

Dartmouth resident Bruce Hetherington, whose 33-year-old son Jamie was killed in a crash on Highway 103 eight years ago, said he was pleased the highway topped the list for potential twinning.

However, Hetherington expressed frustration that there is no commitment for actual work to begin.

"What we have to do is get on with the work," he said. "The longer they wait, the more it (cost) is going to go up."

Joe MacDonald, chief of the Barneys River Fire Department, has also been a vocal critic of a lack of twinning along a 37-kilometre portion of the Trans Canada Highway between New Glasgow and Antigonish.

The section, which has seen 15 fatal collisions since 2009, ranked third on the feasibility list.

MacDonald said the release of the study was a positive step and he believes tolls will help in funding safer highways.

"Everybody in my area has been very positive," said MacDonald. "I came out and told everybody that it would have to be tolls if we expect it (twinning) in the next 10 years and very few people have been against it."

MacDonald said more than 13,000 people have signed two petitions calling for the highway to be twinned.