West Gate tollway: Lengthy delays expected as City Link access roads to shut for up to six weeks

Drivers face the prospect of lengthy summer delays, with some City Link access roads to shut for up to six weeks over the Christmas break.

9News understands the plans are being drawn up as part of the government's holiday works blitz, with temporary closures of some on and off ramps to allow for work on a new West Gate tollway interchange at Docklands.

Transport Infrastructure Minister Jacinta Allan said the government would notify drivers well in advance.

"There's no doubt there's going to be some disruption ahead," she said.

"Those disruptions will be planned very carefully to minimise the impact on motorists."

It came as the government defended increasing tolls on the West Gate Tunnel, even before the road is opened to traffic.

Under a deal done with toll road operator Transurban, toll charges on the project have been rising every quarter, and will continue to increase by 4.25 per cent each year until 2029.

From there they will rise in line with inflation.

When the contract was signed, the minimum fee was set at $3.00 with a peak hour city access charge of $4.80.

But by the time of the road's expected opening in September 2022, the respective charges will have risen to $3.57 and $5.72.

Large trucks will pay $25.92 for each trip through the tunnel.

Opposition Leader Michael O'Brien branded the West Gate tunnel funding deal "a scam".

"This is an absolute gold mine for Transurban shareholders but unfortunately it's Melbourne motorists who are paying for it," he said.

Labor MP Cesar Melham, who represents Melbourne's western suburbs, told 9News the tolls were "regrettable".

"No one wants to actually pay more toll; I certainly don't," he said.

"But unfortunately that's the way it is these days.

"I think people would understand we've got to pay for it somehow."