Center City transformed into a steel maze of security gates and fences Friday, guarded by scores of local and federal police authorities, who claimed the streets ahead of the imminent arrival of Pope Francis.

Concrete barriers blocked major routes such as Market Street East and smaller streets across the area, and pedestrians found themselves stopped from walking to one place from the other.

An alphabet soup of police and investigative agencies - FBI, HSI, TSA, CBP - joined dozens of Philadelphia police officers on and around the Benjamin Franklin Parkway, a main stage for this weekend's papal activities. National Guard soldiers took posts in Fairmount, Spring Garden, Center City, Chinatown, and elsewhere.

"It's totally ridiculous," said Keith Woolridge, 57, of Center City, as he walked past guardsmen on Chestnut Street. "It's an overkill."

Woolridge said he would not attend the papal events, not wanting to battle big crowds, but expressed sympathy for elderly people who may have to walk long distances.

Mark McDonald, spokesman for Mayor Nutter, said the magnetometers and street closures were mandated by the Secret Service.

Rob Hoback, spokesman for the Secret Service, said the list of closures and checkpoints was released Sept. 10.

"That information has been out for a while, so folks have known for a couple of weeks," he said. "It's a big area, and if you're going to open at 6 a.m., the area has to be secured and swept the night before. So you have to start shutting streets down and making sure the area is clear."

Nutter has promised a big, safe, celebratory event that people will talk about for years.

On Center City streets Friday, many were already walking long distances.

"There's no way out!" a Sheraton hotel worker shouted to a group of people walking west on Race Street, hoping for an exit but instead meeting mesh fencing.

People arrived in the city from across the state and the nation, from Chicago, Denver, and Atlanta, eager to see Francis in person during his first visit to the United States.

"This is a pilgrimage for me," said Don Grossnickle, a Catholic deacon from Chicago, "to be close to the Holy Father. . . . With all due respect to Pope Benedict, he didn't have the same rock-star appeal."

Those seeking to enter the Parkway, to stroll in advance of the pope's arrival, were closely searched at security checkpoints, first passing through magnetometers and, in some cases, being checked a second time with handheld wands.

The security zone known as the Secure Event Perimeter - encircling the Parkway from City Hall to the Art Museum - took effect at 10 p.m. Thursday, initially limiting access to residents, businesses, and certain authorized people. Everyone else could enter through security gates beginning Friday at 6 a.m.

Vehicles were prohibited in the Secure Event Perimeter beginning at 6 a.m. Friday. On Friday evening, inbound traffic was banned from entering the larger "traffic box," from 38th Street to the Delaware River and from Spring Garden Street to South Street.

Further closures Friday would limit traffic on the Schuylkill Expressway, I-676, and City Avenue. The Ben Franklin Bridge will stay closed until noon Monday.

Unprecedented crowds were expected to fill the Parkway and beyond for a papal parade Saturday, with perhaps a million people anticipated for a public Mass on Sunday.

"There's a lot of security, but I'm glad to see that," said Angelica Lopez of Castle Rock, Colo. "Everything's been very organized."

She; her husband, Al; and a friend, Laurie Quintana, also of Colorado, decided to wait in line to see the Liberty Bell on Friday, as crews set up chairs and barriers around Independence Mall ahead of Francis' appearance there Saturday.

The three are part of a group of 70 from the Archdiocese of Denver who came for the World Meeting of Families and the papal visit.

Tourists had Old City and the Independence Mall area to themselves, moving around security perimeters to see the sights with help from the huge number of police in the area, who offered directions and tips.

At Third Street and Market, Gabriela Cosma, 29, and Masaya Jimbo, 30, took their two small dogs out for a walk and marveled at the empty streets.

"We thought we were going to have to carry them so no one would step on them," Jimbo said. "It feels like it's early, early on a Saturday morning."

To the west, on Market near 17th Street, the beeping of magnetometers replaced the normal sound of car horns as people trying to reach the Parkway underwent airport-style security checks. Transportation Security Administration agents screened individuals front and back, their arms raised, and squeezed their shoes.

Also on the scene Friday were police from Homeland Security Investigations (HSI) and U.S. Customs and Border Protection (CBP).

Some civilians groaned at the security measures, including a Center City resident trying to reach the Reading Terminal Market to buy vegetables.

"Can we come back with groceries?" she asked. The answer was yes.

On the Parkway, visitors and workers in golf carts navigated the traffic-less lanes as Border Patrol and Secret Service agents mingled. Traffic lights had gone dark. There was no need for them.

Much of Broad Street was blocked near City Hall, creating a maze for those navigating with suitcases, baby strollers, and wheelchairs.

"We're going in a circle," said Frank Plonski, 72, of Lansdale, as he moved two empty wheelchairs while his wife, Jo, lugged a suitcase near Broad and Chestnut Streets. The wheelchairs were for family members visiting from New Mexico, the Plonskis said.

Away from City Hall, people gawked and snapped pictures of weirdly empty streets.

Chrystyna Pospolyta, 52, took the PATCO rail line from Haddonfield to Center City, wanting to witness Philadelphia's shutdown, then return home to hunker down for the weekend. She snapped photos of the eight-foot security fences on 16th Street.

"I wanted to see those up close," she said.

At HipCityVeg, a vegan restaurant near Rittenhouse Square, the flood of visitors and security personnel offered an opportunity.

Employee Ajisa Hiller, 22, strolled through the street offering free samples of "Groovie Smoothies" to soldiers and passersby.

"Honestly, for the working people and people who have things to do, it is a pretty big hassle," she said of the restrictions on movement.

Still, she said, it will benefit the city to stand in the papal spotlight.

"Philly definitely needs it," she said.

215-854-4906 @JeffGammage