The city that attracts Amazon's new second headquarters would gain 50,000 jobs, billions of dollars in economic development, and potentially a lot more people on roads and public transportation.

The Philadelphia region can handle it, said Barry Seymour, executive director of the Delaware Valley Regional Planning Commission. Though its population has grown recently, the city is still blessed with a transportation infrastructure built for more people than live here today, he said.

A sudden influx of 50,000 workers is "an awful lot to dump into one place," Seymour said. "But Philadelphia as a city has lost 50,000 workers."

Amazon announced Sept. 7 it was seeking a home for its second headquarters, dubbed HQ2, and issued a request for proposals from cities across the country. The request, which must be answered by Oct. 19, described public transportation and highway access as a priority.

In the race to win this prize, Philadelphia's transit system is one of its selling points, said Adie Tomer, a Brookings Institute fellow with expertise in city infrastructure.

"Philadelphia has amazing transit relative to almost all but five or six other markets in the country," Tomer said.

Philadelphia has a sprawling commuter rail network, two robust subway lines, buses, and trolleys, and it's likely that if Amazon decides to come here, the company will be in a position to request that the region build any additional transportation connections.

"When they go into negotiations with the city, county, and even the state, they will make sure the infrastructure projects they're interested in will probably be delivered," Tomer said.

Some of those upgrades are probably coming whether or not the tech giant decides to move in. The city is focusing on three sites to pitch to Amazon: two in University City and the Navy Yard. Camden County and Bensalem also are marketing themselves to Amazon. All of the proposals focus on areas where transportation expansion projects are either underway or planned.

The Navy Yard

The Navy Yard has perhaps the most ambitious transit plan attached to it: a subway extension. One of the disadvantages of the site is that the Broad Street Line terminates at AT&T Station, about a mile shy of the campus where more than 13,000 now work.

The idea of extending the Broad Street Line dates back nearly a decade and has seen only halting progress. Cost estimates for the extension, pushed hard by heavy hitters like U.S. Rep. Robert Brady (D., Pa.) and union boss John Dougherty, are in the $400 million range. A step in the process is due to be completed this December, said Jeff Knueppel, SEPTA's general manager, when a PennDot-funded study is expected on transportation options for the Navy Yard.

Among the ideas are three variations of a rail extension. Another is enhanced bus service. Philadelphia Industrial Development Corp. now runs a shuttle service with six buses that loop around the 1,000-acre campus every 10 minutes and another that provides trips between the Navy Yard and Jefferson Station.

About 15 percent of workers use the shuttle service, while others drive, bike, or walk from AT&T Station, said Prema Katari Gupta, senior vice president for the Navy Yard at the PIDC. She said there had been conversations with SEPTA about the transportation authority's providing a more robust bus service and with the city about improving the bike access to the site.

"We have a system that meets our current demand, but we're always looking," Gupta said. "I look at it all as incremental."

West Philadelphia sites

The nearest transportation hub to Schuylkill Yards and uCity Square sites in West Philadelphia is 30th Street Station, where 13 railroad lines, five trolley lines, and the El converge and account for 1.1 million trips a day, SEPTA officials said. The number of workers in University City will grow regardless of Amazon's decision, and based on current trends, SEPTA anticipates that many of those workers will be transit users. In the Cira Center, for example, 90 percent of workers take transit, SEPTA reported.

The subway trains themselves can handle the additional ridership, SEPTA predicts, but the station needs work. SEPTA has started phase one of a $37 million upgrade of the site by 2020. Work to replace the headhouse and elevator at 31st Street is underway, and in a matter of weeks, SEPTA will submit a federal grant application to cover the costs of relocating and replacing the elevator on 30th Street and modernizing the entrance to the station, its mezzanine, and platforms.

SEPTA's is coordinating with Amtrak as the national rail company embarks on a 30-year, $6.5 billion plan to remake 30th Street Station. Part of the proposal is to reopen and renovate a tunnel connecting the subway and trolley lines to the train station. Amtrak also anticipates a ridership boost if Amazon comes to the region. Amtrak already has plans to increase the number of Acela Express trains and the number of people those trains can carry with new cars expected in 2021.

Camden and Bensalem

The two proposed sites outside Philadelphia, in Camden and Bensalem, also have public transit access. Along with bus service, Camden has a rail connection to Philadelphia through PATCO and to Trenton with the RiverLine. A long gestating plan to build a rail line connecting Camden to Gloucester County to the south has a feasibility study underway, Seymour said, though no dedicated funds yet exist for the estimated $2.6 billion project.

The region's highways are in the midst of significant renovations, with $1.9 billion going to a rebuild of eight miles of I-95 from Cottman Avenue to Spring Garden Street by 2030, and $1.1 billion on a Pennsylvania Turnpike project to remake the junction of that highway with I-95, a project that could be important for Bensalem's bid for the headquarters on 675 acres of riverfront land.

That community's closest rail stop is the Eddington station, where an average of 90 people board each weekday. That stop also serves two bus routes, and no major renovations are planned, SEPTA reported.

A number of these transit plans are conjectural, with funding or a solid plan not yet complete. If the Amazon headquarters were to come, though, that could be a needed catalyst to get plans off the drawing board.

"It generates a lot of focus and a lot of attention," Seymour said, "and sometimes that's what it takes to move some of these big projects forward."

Join transportation writer Jason Laughlin for a discussion with riders and experts on Monday, October 2, 2017 at the Free Library of Philadelphia. More info and registration: