The bridge is along the route of one of Sydney's most notorious traffic snarls. Credit:James Brickwood On the government's previous announced timetable, these northern tunnels would not be built for a decade or so. Only last week the federal agency, Infrastructure Australia, reported the Western Harbour Tunnel and "Beaches Link" were projects with a 10-year to 15-year time frame. But Ms Berejiklian has created expectations something may happen sooner. "I completely appreciate the frustration of people on the northern beaches and let me assure you that our government has worked very hard behind the scenes to progress that issue," Ms Berejiklian told local station Northside Radio this week. "I'll have more to say about that in the coming weeks," she said. "Watch this space."

The old and the new Spit Bridge on November 19, 1958. Credit:Fairfax Archives Ms Berejiklian's "more to say" will be timed to coincide with the by-elections in the North Shore and Manly caused by the retirement from politics of Jillian Skinner and Mike Baird. The statement places within a long tradition of Coalition promises to progress on the Spit Bridge and northern beaches transport in the lead-up to an election. Before the 1999 state election, for instance, Ms Berejiklian's factional ally Michael Photios said a Coalition government would "immediately" start on a study to consider the transport needs of the northern beaches. "I am very positive about a new road link, presumably by tunnel from Warringah Expressway to the Spit," Mr Photios, then the opposition transport spokesman and now a lobbyist and factional player, said.

In 2003, then Liberal leader John Brogden promised a Balgowlah tunnel before the election that year. And, campaigning before the 2007 poll, Mike Baird ran from Balgowlah Boys High School to Neutral Bay to demonstrate that willing legs and a pair of joggers could beat the tortured public transport and road commute. "NSW commuters can't afford four more years of the same," he said at the time. The Coalition, of course, did not win elections in 1999, 2003 or 2007. Soon after the 2007 election, Labor broke its own promise to widen the Spit Bridge, claiming that costs had unexpectedly blown out. But Mr Baird also said before the Coalition's 2011 victory that he was interested in a tunnel under Military Road, Mosman. "We have to take cars off the road," he said at the time. As well as Ms Berejiklian's comments, a pamphlet sent by Ms Skinner to her North Shore electorate saying she had seen plans for the tunnel has raised expectations of an announcement.

But in the face of the history, even supporters of a tunnel are cautious of any new promises. The mayor of Mosman, Peter Abelson, said: "I would be very pleased but it would be very much tempered by my view of the realism of the prospect.. Labor's infrastructure spokesman, Michael Daley, called an announcement a "by-election, pork-barrelling con job". "Now we find the government wants to spend $2 billion on a tunnel to the northern beaches when there are so many other areas of Sydney which should be higher on the priority list," Mr Daley said. Jeff Morris, a councillor on North Sydney Council, said better public transport needed to be part of the solution.

"What is it with Liberals and motorways?" Cr Morris asked. "They trot this out whenever they think they're in trouble electorally." A spokesman for Roads Minister Melinda Pavey, meanwhile, said Roads and Maritime Services and Transport for NSW had been carrying out technical investigations for Beaches Link since October and would "continue to keep the northern beaches community informed".