It will span an area larger than 40 football fields and feature restaurants, entertainment venues, office space, a hotel and plenty of stores.

At that size, the Royalmount mega-mall — a development planned at the junction of Highways 15 and 40 — will, for better or worse, have a seismic impact on the surrounding area and the retail landscape of Montreal as a whole.

The project's backers say it will offer a unique shopping experience on the island. Critics, though, predict it will create traffic woes and eat into the profits of downtown shops.

It was the Town of Mount of Royal alone that had the power to approve the $1.7-billion project, and its town council has already given the go-ahead. The developer announced last week it will break ground later this year.

Yet given the potentially wide-ranging consequences for Montrealers, some wonder if the City of Montreal, and the surrounding municipalities, should also have a say in whether the mega-mall goes ahead?

Raphaël​ Fischler, an urban planning professor at McGill University, puts the question this way:

"The main issue that this project raises is this: is it OK for a municipality to make a land development decision on its own when that decision will have major impacts on surrounding municipalities?"

"Is it OK for a municipality to make a land development decision on its own when that decision will have major impacts on surrounding municipalities?" asked Raphaël​ Fischler, an urban planning professor at McGill University. (McGill University)

Traffic, impact on small businesses among key concerns

Projet Montreal was against the project before it took power last fall, and remains skeptical about how it will affect the city.

"There were serious concerns about the impact on traffic and the impact on the commercial vitality of the city," Éric Alan Caldwell, a Projet councillor responsible for planning and transport on Montreal's executive committee, told reporters earlier this week.

"We still have those same concerns." ​​

Projet Montréal's Luc Ferrandez, borough mayor of Plateau-Mont-Royal, was blunt when the mega-mall was first announced, saying it would multiply traffic and pollution problems as well as hurt the local economy.

"Montreal is at a turning point. We have to choose between our own identity … or accepting an American way of life, and maybe a Dubai way of life," he said in 2015.

Whether or not the city comes around, the developer — Carbonleo — maintains it can go ahead with the project because it falls squarely within TMR land.

According to Caldwell, though, the agglomeration council, which is comprised of the City of Montreal and the other municipalities on the island, does have authority when it comes to impact on traffic and retail outlets nearby.

"We met with the promoter to share our concerns and we are in dialogue," Caldwell said.

Royalmount centre would include a piazza area and terrasses. The promoter says opening day would be in 2022. (Carbonleo)

Developer ready to go ahead

Andrew Lutfy, president and CEO of Carbonleo, said he wants Montreal on board, even if he doesn't believe it's necessary.

"At this point, they are really just digesting the project and I guess they are going to come back to us," he told reporters earlier this week.

Carbonleo isn't new to this kind of project. It is also the developer behind Quartier DIX30, a sprawling development in Brossard on Montreal's South Shore.

That complex, he said, succeeded in luring shoppers from the island. An estimated 15 per cent of DIX30's revenue comes from Montreal residents, Lutfy said during speech at the Canadian Club of Montreal.

At the same time, he tried to downplay concerns that Royalmount would hurt small businesses or the downtown core.

Andrew Lutfy is the president and CEO of Carbonleo, a Quebec-based real estate firm. (Carbonleo)

Carbonleo believes in the future of downtown, he said, and is putting $500 million into a commercial project on Ste-Catherine Street near Mountain.

He also said there will be measures introduced to reduce the impact on traffic at the already busy Décarie Interchange, including multiple entrances and exits away from the highways.

A planned footbridge linking the centre to de la Savane Metro station is also in the plans. Lutfy estimates as much as one third of clients will come by public transit.

Regional approval?

Fischler said the "law is on TMR's side for now, and one can understand why a municipality doesn't want to give up some of its autonomy in land-use decision-making." ​​

But, he pointed out, the Quebec government has in the past taken away municipal autonomy in order to protect agricultural land.

Carbonleo plans to build a pedestrian bridge over the Décarie expressway to help people access its new megamall. (Carbonleo)

In Europe, he said, many European countries have instituted legislation that subjects large suburban developments to higher-level control in an attempt to limit the damage that suburban retail can do to downtown retail.

"Perhaps the law in Quebec should be changed to reflect the fact that some local planning decisions have regional impacts and should be managed at the regional level?"

The office of Martin Coiteux, the minister responsible for the Montreal region, did not immediately return a request for comment Sunday.