Hundreds of thousands of visitors to Children's Hospital of Pittsburgh will face additional challenges when a new $625 million campus opens May 2 in Lawrenceville, a tightly packed urban neighborhood with narrow streets and limited parking.

The hospital has spent years and millions of dollars on planning and traffic improvements and held scores of meetings with nearby residents who are both eager and skittish about the arrival of the sprawling 10-acre complex.

"This is an interesting endeavor. They're landing this amazing facility right in the heart of a city neighborhood," said Pittsburgh City Councilman Patrick Dowd.

Getting to, and around, the current hospital complex in the heart of Oakland is no picnic. Parking is a daunting and at times frustrating puzzle, followed by navigating the hospital's convoluted maze of corridors, stairways and elevators.

The new campus will bring two significant improvements.

Three parking garages within the complex will have 1,400 spaces, enough to accommodate every visitor to the hospital, said Eric D. Hess, vice president and project executive.

Visitors will be directed by their appointment cards to the garage most convenient to their destinations in the hospital, and signage and design improvements will make a "night and day" difference in getting around once inside, he said.

Destinations in the hospital will be numbered like gates in an airport. Signs will use the numbers, rather than designations like "radiology" or "anesthesia" that can become obsolete as departments shift locations over time.

"3A will always be 3A, no matter what's there," Mr. Hess said.

Several road improvements have been made around the hospital site, but the principal access route, Penn Avenue, remains a two-lane city street.

"I think we've done as well as can be done given the geography," Mr. Hess said. "I wish there was a major interstate nearby."

The new site is served by public transit, but only a fraction of what is available to the Oakland site.

"Public transportation [to Lawrenceville] is probably never going to be better than what we have in Oakland," Mr. Hess said.

The new hospital is bounded by Penn Avenue, 44th and 45th streets and Garwood Way.

To accommodate the added traffic volume, Penn Avenue, 44th Street and Garwood Way have been widened in spots and at least five new left-turn lanes have been added along Penn Avenue and 44th and 45th streets.

Stretches of three streets that formerly were one-way have been converted so that the entire hospital perimeter is open to two-way traffic.

New traffic signals have been installed at Friendship Avenue and Howley Street, and at Butler and 45th streets.

Still, there is no ideal way to get to the new Children's.

Most visitors from the south, west and north will use Route 28 to the 40th Street Bridge into Lawrenceville. The hospital's opening will coincide with Route 28 construction that will impose lane restrictions and cause traffic jams in both directions.

Motorists seeking to avoid the Route 28 snarls will cross the river into Lawrenceville, joining the increased traffic from the hospital.

"The convergence of all these things happening at once is a concern," said Tony Ceoffe, executive director of Lawrenceville United, a community group that has been closely involved in planning for the new campus.

"It's a little scary," Mr. Hess acknowledged.

The 1,400 on-campus spaces in Lawrenceville are more than double the number available at Children's in Oakland, Mr. Hess said. No patient or visitor will have to park off-site.

Each of the three garages will have multiple entrances and exits to minimize the amount of traffic circling the complex in search of access.

But the garages "don't come close to accommodating staff needs," he said. So Children's has developed a 1,500-space surface lot between 55th and 57th streets along the Allegheny River and will use shuttle buses to move employees back and forth.

What remains to be seen is whether workers will eschew the satellite lot and 10- to 15-minute shuttle ride and look for parking in the neighborhood around the hospital.

One of the biggest concerns of residents is having their already scarce on-street parking gobbled up by hospital staffers, Mr. Hess said.

Mr. Dowd, who said he repeatedly heard those concerns when he campaigned door to door for council in 2007, has resuscitated the city's Residential Permit Parking Program, which limits nonresidents to two hours of parking along streets in designated zones on weekdays.

Some Lawrenceville residents have begun the process of gathering petition signatures and applying to the city for the designations, he said.

The Lawrenceville site is served by far fewer Port Authority routes and stops than the Oakland site, and that is unlikely to change, although discussions about increased service are under way, Mr. Hess said.

According to the Port Authority Web site, the new campus is served primarily by the 86B Frankstown route along Penn Avenue, with trips every 15 to 20 minutes.

With most of Port Authority's East End service routed through Oakland, a steady parade of buses serves the current hospital.

"We'd like to see more [transit]," Mr. Hess said, noting that many employees, patients and other visitors rely on buses.

The Port Authority is in the midst of a major overhaul of its bus routes and is developing three options, which it expects to make public next month. Each would increase service to the new hospital, said Peter S. Behrman, assistant general manager for service planning and development.

Those changes won't be implemented until next year. But if demand warrants after the hospital opens, Port Authority will add service on existing routes, he said.

Planning for the crowds and traffic at the new complex goes back more than seven years.

Mr. Ceoffe said he's attended "far in excess" of 20 community meetings related to the hospital.

"The hospital has been exceedingly accessible and has done a tremendous job of coming out to meetings and hearing the concerns of the community," Mr. Dowd said.

"I guarantee there will be issues that emerge," he said. "We're all going to have to see what happens when the hospital opens, and adjust to what happens."