The GTA could be getting a second Union Station, but this one would be at Pearson airport.

The Greater Toronto Airports Authority (GTAA) released new images of the multi-modal transit centre it wants to build across from Pearson's two main terminals by 2027.

If built, the centre would connect with a number of transit lines including the Eglinton Crosstown LRT, Mississauga's bus rapid transit plan and potentially a high-speed rail line to the Kitchener-Waterloo area. It would also become the passenger processing and security screening area.

"Now is the time to ensure that better transit options are in place," said GTAA CEO Howard Eng in a statement about the plans.

"Otherwise we risk squandering the significant opportunities that are part and parcel of the exciting growth that the airport, the city and the region are experiencing."

Currently, the Union-Pearson Express is the only rail line to the airport, though several transit services offer bus routes.

The GTAA said it's had preliminary discussions with representatives from all levels of government this year and intends to continue that work. There's no price tag for the mega-project yet.

Mississauga Mayor Bonnie Crombie welcomed the plans, saying the western GTA needs a major travel hub. (John Rieti/CBC)

Mississauga Mayor Bonnie Crombie said she's excited by the prospect, even if it's still years away.

"It starts by thinking about Toronto Pearson as more than just an airport," Crombie told CBC Toronto.

Linda Jeffrey, Brampton's Mayor, said the transit hub would be a boon to the western GTA and create a "critical connection between Brampton and the rest of the world."

Transit hub aims to cut down on car traffic

The development would make Pearson one of the world's "mega-hub airports," and focuses on not just travellers but the 300,000 people who work in the airport area. Currently, the GTAA says 93 per cent of those workers drive to their jobs.

The GTAA said that's worrisome, especially because road travel times are predicted to get between 25 to 35 per cent worse by 2043.

The GTAA's new plan calls for travellers to check in at the transit hub building. (Aaron Vincent Elkaim/Canadian Press)

"We need to get those people out of their cars and connected with public transit," Crombie said.

Travellers aren't much better off. Only 10 per cent of the GTA's jet set take transit, compared to 36 per cent at London's Heathrow, 50 per cent in Hong Kong and 60 per cent in Shanghai.

The GTAA said NEPTIS Research Foundation found there are around one million car trips to the airport every day.

New building designed as gateway to airport

Crombie said cost could be the biggest barrier to building the new transit hub, especially when there are so many transportation projects vying for public funding in the region. While every community has its own transportation demands, "all roads and all rail must lead to Toronto Pearson," she said.

The red circle outlines the site where the GTAA hopes to build the transit hub. (Greater Toronto Airport Authority/Submitted)

The new renderings of the transportation hub feature one traditional car drop-off loop, but also connections with several rail lines, including the TTC, UP Express and GO Transit. Bus services, like Mississauga's rapid bus transit system, will also connect with the hub.

There's also more public outdoor space in the design, as well as several buildings that the GTAA envisions will feature a mix of hotels, offices and shopping.

The entire development would be built on what's currently parking space.

Pearson is already a massive operation, with some 41 million passengers passing through each year, as well as nearly half of Canada's air cargo.

Eng, who heads the not-for-profit airport authority, is set to lay out this vision at Brampton's State of the City event on Tuesday.