Winners and losers from opening of the new motorway to Sydney Airport

A new motorway to Sydney Airport might slash travel times for motorists driving from a WestConnex interchange at St Peters but internal analysis by the state’s transport agency warns of the potential for longer delays for drivers using several key roads near Botany.

The ribbon will be cut early on Friday on the final crucial section of the $2.6 billion Sydney Gateway motorway to the airport’s domestic and international terminals, ahead of the opening to motorists on Sunday morning.

The final section of the Sydney Gateway motorway will open to motorists early on Sunday morning.Credit: Dominic Lorrimer

A confidential analysis prepared by Transport for NSW for the premier’s department cites the management of traffic at the terminals’ pick-up and drop-off areas as a key risk, as well as the fact that state officials have “no control over [the] internal airport road network”.

The analysis in late June warns that the “departures roadway is a key concern”.

Once the final section of the toll-free gateway opens, it will be a four-minute drive from the St Peters interchange for WestConnex to the domestic or international terminals, saving motorists up to 17 minutes by avoiding local roads and traffic lights in Mascot.

While travel times will be cut, the briefing document to the premier’s department warns that “congestion in and around the airport precinct remains”.

It also cites the “potential for increased delay” on the Wentworth Avenue, Mill Pond Road and Foreshore Road intersections near Botany, as well as “potential delays to a lesser extent” on West Botany and Marsh streets in Arncliffe.

“Traffic may approach these intersections in a different pattern following the opening of Sydney Gateway,” it says.

Using the new motorway to bypass traffic lights will be welcomed by motorists, but Transport for NSW officials have warned in the confidential documents that it reduces their ability to manage the flow of traffic in busy periods.

Transport for NSW said in statement that it expects a period of adjustment while motorists get used to the new routes that become available with the addition of the gateway to the road network.

“Technology that monitors travel time on key routes has been installed across the project area and will help Transport understand the road network’s performance. This will provide valuable data that will help to identify congestion hotspots and enable Transport to adjust road operations and deliver messaging to drivers accordingly,” it said.

The agency has set up a joint operations centre at Eveleigh to monitor the motorway in the weeks after the final stretch is opened.

All up, the gateway comprises five kilometres of motorway and 19 bridge structures, and has capacity for 100,000 vehicles a day.

Transport for NSW secretary Josh Murray said the new motorway would also divert 10,000 trucks a day off the roads around Mascot.

“We have opened this in a staged fashion so that people get used to it over time. But those big changes will come into effect on Sunday,” he said on Monday.

“Transport is working closely with Sydney Airport to make sure that on a daily basis we can manage the in and outflow from the airport. But it is a busy precinct. There is often congestion around the airport.”

One of the busiest periods on roads near the airport can be Monday mornings at the domestic terminals.

Roads Minister John Graham said on Monday that the final stretch of the gateway to be opened was the “key stage” because it would open up the airport to traffic and would promise a smoother ride for motorists, especially those from the west and southwest. “It also means separating out freight traffic from commuter traffic. That’s good news in this busy airport precinct,” he said.

Sydney Airport said it was doubling the number of roadside staff across the precinct to nearly 60, while overflow drop-off areas would be switched on to manage traffic flow at peak periods.

Taxis driving to the domestic terminals from 4am to 7am will also drop off passengers on the ground floor arrivals level to alleviate traffic on the departures roadway.

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