Welcome, rail commuters, to the land of heat, ice, and rain.

That is, to the sidewalks, streets, and alleys outside the Gallery shopping mall on Market East.

The mall's three-block central corridor, for decades the weather-beating tunnel for thousands of SEPTA and PATCO passengers, is going to close. Soon. City Council is poised to approve a $325 million Gallery renovation on Thursday, and the developer plans to start demolition in August.

"To do the work we want to do, you have to close," said Joseph Coradino, chief executive of the Pennsylvania Real Estate Investment Trust. "There's significant structural work that needs to go on."

At suburban malls, the concourse is merely the bright, shiny spine along which stores are aligned.

But the Gallery concourse is different. It's the connective tissue for two major transit centers and a subway line, the heavily trod walkway for commuters, shoppers and visitors who descend from points across South Jersey, the Pennsylvania suburbs, and Philadelphia.

The warm-in-winter, cool-in-summer pass is the tile track across which late commuters sprint for trains, where forgetful husbands buy last-minute bouquets and the famished grab a pretzel before boarding.

It's so important to foot traffic that the Philadelphia Redevelopment Authority kept ownership of the concourse even as other parcels were sold. The legislation that enables the mall's top-to-bottom remodeling stipulates that, once work is done, citizens have a legal right to walk the corridor.

Coradino said PREIT can't risk someone getting hurt by walking through an active construction zone, and at any rate government safety regulators would not allow it. The company estimates a two-year closure, during which the Gallery will be transformed into the Fashion Outlets of Philadelphia.

The first stage of demolition will occur between Eighth and 10th Streets. A barricade will block access to the stairs and escalator at 10th and Market Streets. In the second phase, likely to begin next year, construction will move west to 11th Street.

"It's the price of life in the city," said David Bisbee, who commutes from Jenkintown, then walks through the Gallery to reach Nelson architects, where he is a senior project manager. "I don't mind walking outside."

Of course, he said, Market East is not the most scenic street.

It's defined by fast-food joints and discount electronics and cash-for-gold shops. Addicts gather near a methadone clinic.

But the prospect of a renewed, reenergized mall is worth the hassle, Bisbee said.

"All around the city, there are detours on streets that you can't drive on - that's what it takes to get an active, vibrant and economically viable city," he said.

The Gallery was built to accommodate public transit, with the PATCO station at one end and what was then Market East station on the other. That layout - and link to two Market-Frankford subway stations - ensured that huge numbers of potential customers passed through the Gallery every day.

The regular delivery of buyers continued even as the mall faltered.

Today 8,900 people enter or exit the PATCO station at Eighth and Market each day, and 26,000 a day use Jefferson Station.

Many of those will face longer, more roundabout walks to their jobs or destinations.

"That's going to be a terrible inconvenience, especially in periods of extreme weather," said retiree Tony DeSantis, who regularly rides PATCO to Philadelphia from his home in Collingswood.

DeSantis, a former information-technology manager, leads the Delaware Valley Association of Rail Passengers. He wishes PREIT could have found a way to provide a protected indoor tunnel.

"Two years," he mused. "It's going to be miserable."

Coradino recognizes that people will be inconvenienced. At the same time, he can envision the grand christening of a new glass-and-steel mall that will help revive Market East.

"We're going to want to open this," he said, "like a Broadway show."

Once construction begins, people who use the transit stations will generally have to enter and exit at those sites. SEPTA's 11th Street subway will remain accessible from Jefferson Station and from the Market Street entrance to the Pennsylvania Convention Center.

Jefferson Station commuters will use the street-level doors at 10th and Filbert, near the bus station, or those on 11th Street near the Reading Terminal Market. They also can use the Convention Center entrance.

"It's going to be really crowded if everybody is entering and exiting the same exits," said Elana Hollo, who commutes from Melrose Park to Jefferson Station.

She usually catches the 6:59 a.m. train, walks through the Gallery to 10th Street, then goes up to street level on the escalator there - soon to be inaccessible.

Hollo, a lawyer, also worries about personal safety as the mall continues to drain shops, salespeople, and customers. Leases were not renewed in anticipation of remodeling.

"As the stores have closed, it's gotten creepier and creepier down there," Hollo said. "I feel more of a target than ever before."

Today, security guards stand by empty stores. The food court is shuttered. It's quiet enough to hear the canned classical music, formerly drowned in the din.

Only one store is open in the east end. On the west side, a few outposts of commerce endure.

Claire's jewelry, Bath & Body Works, Game Stop, Rainbow clothing, and R.K. Jewelers show no sign of imminent departure.

Their leases are why demolition will occur in two phases, complicating the most complex piece of a hoped-for Market East revival. Developers and government leaders believe the eight-block stretch between City Hall and Independence Mall is poised for rebirth.

PREIT and California-based Macerich Co. plan for Fashion Outlets to host brand-name discount stores and exciting restaurants.

"It's pretty exciting," said City Councilman Mark Squilla, sponsor of the mall legislation, which Mayor Nutter supports.

The bills are expected to pass easily on Thursday.

"I'd love to see the Gallery updated," said Hollo, who has seen the mall decline during her years of commuting. At the same time, "I'd prefer to have some underground access."