Major construction on a new road through the T1 international terminal and a reorganised parking lot should start next week, with the airport warning that the next six months are likely to be the period of biggest disruption.

In the next three years the airport is also planning to build a new multi-storey transport interchange at the domestic terminals, which should make it easier for the state government to schedule extra buses to run to the airport.

At the moment there is only one public bus route that runs to the airport, with the government attributing a lack of space to stop as one of the impediments to putting on more routes.

But the initial work, to begin on Monday, will focus on the international terminal. A new road will be constructed between the open air car park and the multi-storey car park near the terminal.

This will allow motorists to avoid the current confusing drive through the open air car park. A larger pick-up area than currently exists will be constructed in the open air area.

“This out here is the first and last impression of the airport so we absolutely want to get it right,” said Craig Norton, the general manager of parking and ground transport at Sydney Airport Corporation.

Mr Norton said the airport would try to do most of the work at night, but there would still be some disruption for motorists.

"There is no question the next six months is going to have the biggest impact,” he said.

Outside the airport land, the state government is also proposing a number of other road upgrades near the airport. The main entrance to the airport from the north, O’Riordan Street, will become a one-way street. And a road underpass will remove the rail level crossing at General Holmes Drive.

The government has also said it would put on extra bus services between the airport, Bondi Junction, Kingsford and the inner west, but has not said when or what routes the buses would travel.