Philadelphia, Pennsylvania

Philadelphia is the largest city in the U.S. state of Pennsylvania, and the fifth largest city in the United States, with a population of 1,576 thousand. The metropolitan area extends over three states, namely Pennsylvania, New Jersey and Delaware, and has a population of 6,229,000 inhabitants (2021), and is also known as the Delaware Valley.


According to mcat-test-centers, Philadelphia is located on the Delaware River, which is a wide tidal river locally and forms the border between Pennsylvania and New Jersey. The urban region extends over great distances, and the population density is relatively low outside the central city of Philadelphia. In the wider region, there are two more cities that make up a center city, namely Trenton, New Jersey and Wilmington, Delaware. The agglomeration is mainly flat to slightly hilly, with few major differences in height, but here and there the region has more pronounced differences in height up to approximately 100 meters. New Jersey’s side is flatter than Pennsylvania’s.

Downtown Philadelphia is sandwiched between the Delaware River and the Schuylkill River, which converge in the south of the city. The central city of Philadelphia is relatively densely built, but the suburbs are mostly sparse to semi-rural. Gradually the suburbs turn into exurbs and then the countryside. The urban area of Philadelphia borders that of the region around New York City, beyond Trenton the suburbs are more focused on the New York region.

The urban area stretches diagonally for approximately 75 miles from Delaware to central New Jersey. The suburban area is larger on the Pennsylvania side than on the New Jersey side, the suburbs extend from the Delaware River to about 50 to 60 kilometers away, on the New Jersey side this is limited to about 20 kilometers. The countryside between the Philadelphia region and the Harrisburg and Allentown regions is relatively densely populated.

The first ring of suburbs around Philadelphia are located in forest areas, the outer ring are mostly located in more agricultural areas surrounded by meadows. The New Jersey side has a mix of forest and meadows in which the suburbs are located. Northern Delaware also has a relatively large amount of forest around the suburbs.


The population density of the city of Philadelphia is approximately 4,500 inhabitants per km². The center city coincides with Philadelphia County and forms a single administration. The population density of the suburban counties is usually between 1,000 and 1,500 inhabitants per km², lower in the more exurban areas, which also have a lot of countryside. The population has been declining since the 1960s, when the peak of more than 2 million inhabitants was reached. Some of the residents have moved to the expanding suburbs in the forests surrounding the city and some have migrated to the southern United States.

The New Jersey suburb of Camden is one of the most criminal and impoverished cities in the United States and is in serious disrepair. Trenton doesn’t fare much better in that regard, but many small suburbs are prosperous. Virtually the entire suburban area in New Jersey, Pennsylvania and Delaware consists of affluent suburbs, most of which have a population of several thousand people and thus there are hundreds of small suburbs that together form a large built-up area.

Population growth

The metropolitan area of Philadelphia is located in 3 states, spread over 9 counties. Philadelphia itself is also a city-county.

Year Philadelphia Delaware Chester Montgomery Bucks Burlington Camden Gloucester New Castle total
1920 1,824,000 173,000 115,000 199,000 82,000 82,000 191,000 48,000 148,000 2,862,000
1930 1,951,000 280,000 127,000 266,000 97,000 94,000 252,000 71,000 161,000 3,299,000
1940 1,931,000 311,000 136,000 289,000 108,000 97,000 256,000 72,000 180,000 3,380,000
1950 2,072,000 414,000 159,000 353,000 145,000 136,000 301,000 92,000 219,000 3,391,000
1960 2.003,000 553,000 211,000 517,000 309,000 224,000 392,000 135,000 307,000 4,651,000
1970 1,949,000 600,000 278,000 624,000 410,000 323,000 456,000 173,000 386,000 5,199,000
1980 1,688,000 555,000 317,000 644,000 479,000 363,000 472,000 200,000 398,000 5,116,000
1990 1,586,000 548,000 376,000 678,000 541,000 395,000 503,000 230,000 442,000 5,299,000
2000 1,518,000 551,000 434,000 750,000 598,000 423,000 509,000 255,000 500,000 5,538,000
2010 1,526,000 559.000 499,000 800,000 625,000 445,000 514,000 291,000 559.000 5,818,000
2020 1,601,000 576,000 535,000 857,000 646,000 462.000 523,000 303,000 571,000 6,074,000
2021 1,576,000 574,000 539,000 861,000 646,000 464,000 524,000 304,000 572,000 6.060.000

Philadelphia has had a turbulent population development. It was a very large city early on, with the population peaking in 1950 at more than 2 million inhabitants. Since then, the city has lost half a million residents, a trend that began in adjacent Delaware County beginning in the 1970s. Suburban counties have grown strongly since the 1950s, although the rapid growth since the 1970s has leveled off. Growth is now somewhat more limited, a trend seen in many major cities in the northeast of the country. Due to low growth, the Philadelphia metropolitan area has fallen from the 4th largest metropolitan region in the early 2000s to the 8th largest metropolitan region in 2017.

Road network

The highway network in the Philadelphia metropolitan area.

Philadelphia has a grid pattern in the street network in the central city, but virtually none outside it and the road network consists of winding main roads. The motorway network does not have a clear structure either. Interstate 95 is the main highway passing through the metropolitan area, although the New Jersey Turnpike provides a shorter and faster route between Washington and New York City. Because I-76, I-276 and I-476 are partly or wholly toll roads, they do not function as commuter routes due to the limited number of connections. Thus there are quite large areas without major through roads. The low building density of the many suburbs also plays a role here. Several US Highways crisscross the area, often with short stretches of highway. US 1 is one of the largest urban arterials in Philadelphia with up to 12 lanes wide.

On the south side of New Jersey, two parallel highways run through the urban area, the New Jersey Turnpike, which is intended as a through route, and Interstate 295, which connects the suburbs on the New Jersey side of the metropolitan area. To the south, two highways radiate out from Philadelphia, State Route 55 and the Atlantic City Expressway, connecting Philadelphia to the New Jersey coast. There are four highways to the west, of which only Interstate 76 is through. US 1, US 30 and US 422 are regional approach roads that are partly built as a highway.

To the north is Interstate 476, a branch of the Pennsylvania Turnpike. This highway leads to Allentown and Scranton. Interstate 276 forms the city ‘s northern bypass and connects south of Trenton to the New Jersey Turnpike. Interstate 195 connects Trenton to the urbanized coastal area south of New York. Some of these suburbs are closer to Philadelphia than New York.

In addition, due to its location on the Delaware River, the metropolitan area is dependent on bridges. A number of iconic bridges span the Delaware River, including the Benjamin Franklin Bridge, which had the longest bridge span in the world for several years since it opened in 1926, I-76 ‘s Walt Whitman Bridge, and the landmark Delaware Memorial Bridge, which consists of two side by side located suspension bridges over the mouth of the Delaware River between New Jersey and Delaware. All bridges over the Delaware River are toll roads.

Bridges in the Philadelphia Area
Benjamin Franklin Bridge • Betsy Ross Bridge • Commodore Barry Bridge • Delaware Memorial Bridge • Tacony Palmyra Bridge • Walt Whitman Bridge


In 1932, a plan was unveiled that included a system of parkways around Philadelphia, similar to that of New York City which was built at that time. The economic depression and the lack of a politically strong leader prevented any project from getting off the ground. World War II delayed the plans even more, and the parkway plans had been turned into regular highway plans after World War II. Motorway construction began in the 1950s, but it was not until the 1960s that freeways were built in Philadelphia itself. Its construction was messy, resulting in a chaotic and inefficient highway network. On July 1, 1977, it was decreed that all funding for planned highways was halted, effectively ending highway construction in Philadelphia. After that date, most deliveries took place in New Jersey and Delaware.

The failure to build the parkways in 1932 and the abandonment of planned highways in 1977 has left the city with a very inefficient and outdated highway system that is structurally in poor condition, while the state of Pennsylvania already ranks poorly in terms of the state of the road. road network.


Congestion is especially common on I-76, the Schuylkill Expressway to downtown Philadelphia, as this road has only 2×2 lanes. In addition, traffic jams on I-95 through Philadelphia can occur. There are usually no traffic jams on the various toll roads of the Pennsylvania Turnpike and New Jersey Turnpike. Because a lot of traffic is handled on the secondary road network, the delay of a commuter is less obvious than in other cities, where it mostly goes via the highways. The city has a neglected highway network, and quite a few bridges and overpasses in several cities are reaching the end of their life, putting funding towards these objects rather than improving traffic flow. There is a significant difference per state.

Philadelphia, Pennsylvania