Motorists can expect more than two years of increased traffic congestion around Sydney Airport during construction of the Sydney Gateway project.
However, when completed, the Sydney Gateway project is forecast to provide big reductions in travel times to the airport.
The state government has released a joint environmental impact statement (EIS) and draft major development plan (MDP) for public comment.
Minister for Transport and Roads Andrew Constance said the new roads would have the capacity to carry 100,000 vehicles a day and provide a new route for around 10,000 trucks a day.
"This project will improve public transport to and from the airport by providing faster and more direct access for buses, giving people freedom to choose how they move," he said.
Mr Constance said previously contracts for the project, which is expected to cost $2.2 to $2.6 billion, were expected to be signed in mid-2020 and work completed by 2023 to coincide with the opening of WestConnex.
The project will provide new road links between airport terminals and WestConnex at St Peters interchange, consisting of:
- A new elevated access viaduct and overpass from Qantas Drive into Terminals 2/3 Widening Qantas Drive to three lanes in each direction.
- A new access road to Terminal 1 from the Sydney motorway network via St Peters interchange.
- Four new bridges over Alexandra Canal, and new overpasses across the Botany Rail Line and Canal Road.
- New and upgraded intersections along Qantas Drive and Airport Drive.
The project will also provide new road links to Sydney Airport land, connecting holdings on either side of the Botany rail line and freight facilities on both sides of Alexandra Canal.
An active transport link will maintain cycle and pedestrian connections between Tempe, airport, Sydney CBD and Mascot.
The EIS / MDP said the project could be constructed without major reconfiguration of the existing road network.
"However, there would be substantial works required along Airport Drive, Qantas Drive and Sir Reginald Ansett Drive and to facilitate connection of the new road links to the existing road network," the document said.
"Two lanes would generally be maintained in each direction along Qantas Drive and Airport Drive during Sydney Airport's operating hours when traffic volumes are highest.
"However, there would be periods when the number of available lanes would need to reduce to facilitate construction.
"Where possible, these would be conducted during periods of lower traffic volumes.
"There would be impacts to intersection performance within or near the project site, particularly in the vicinity of Terminals 2/3, which would lead to additional congestion and delays for Sydney Airport customers, commuters, public transport (buses) and freight.
"Temporary changes to active transport routes, including relocation of the existing Alexandra Canal cycleway, would lead to an increase in travel distance of about 580 metres.
"There would also be impacts to some car parks and parking areas on Sydney Airport land."
The document said a construction traffic and access management plan would be prepared to mitigate impacts.
Short-term road and lane closures would be undertaken during night-time hours as far as possible, although major crane lifts would occasionally require full weekend closures, with detours established to maintain access to terminals
The document said access to the airport would be maintained at all times during operational hours
Big reductions in travel times were forecast once the project was completed.
Travel times to the airport were expected to be cut by up to 23 minutes in 2026 and up to 30 minutes in 2036, compared to existing alternate routes through Mascot.
Daily traffic flows along O'Riordan Street and Botany Road were forecast to drop by up to 30 per cent.
There would also be reduced travel times to Port Botany of up to 17 minutes in 2026, increasing to more than 20 minutes in 2036.
The document said the new access roads to Sydney Airport land would facilitate proposed developments under the Sydney Airport Master Plan 2039.