Today, the 46,730-mile Interstate System includes approximately 2,900 miles of turnpikes. The PA Turnpike stretches 359 miles from Ohio to New Jersey, plus it has spurs totaling 172, mostly the Northeast Extension from the Philly area to Wilkes-Barre/Scranton. The turnpike in PA includes Interstate 76, Interstate 476, Interstate 276, a chunk of Interstate 70 (where it runs along I-76), and in the future the long-awaited completion of Interstate 95.
Unlike Interstate 80, the major free highway on the north side of the state which does not provide access to any of the state's major population areas, the Turnpike connects all of the largest cities in the state. Included along the turnpikes are Philadelphia, Pittsburgh, Harrisburg, Allentown, and Wilkes-Barre/Scranton.
Despite what you may have seen on "The Office," there is no train that runs the length of Eastern Pennsylvania. Actually, public transportation in this region is almost nonexistent. There is, however, a bus company that is quite reliable and fairly priced if you are looking to come or go from Philly, New York or a handful of town surrounding the Allentown area.
Bieber Tourways offers buses from 30th St. Station (train) in Philadelphia, midtown Manhattan and JFK Airport in New York. Within the Lehigh Valley, there are stops in Bethlehem, Allentown, and Wescosville. You can also choose to ride to Quakertown, Kutztown and Harrisburg. If you're looking to have some fun for the weekend, take the bus to Atlantic City.
The bus offers a good alternative for getting to and from the large airports. I rode this bus quite frequently when I lived in NY and found them to be very punctual (so be on time because they won't wait for you) and efficient. On numerous occasions, the driver avoided traffic on busy I-78 or PA-476 by taking back roads and still got to our destination on time.
Prices have recently changed so check the website for the newest charges (it was $16 one-way before, and I don't think it's been raised much).
Baggage rules (from the website): "Only hand baggage can be carried on board and must be accompanied by passengers. Because of space limitations, we must limit each passenger to two (2) suitcases and one (1) carry-on. The maximum baggage liability is $50.00 per bag."
The bus station @ Hamilton Street and American Parkway is, unfortunately, not the safest place in town. This where buses go to/from Newark & JFK airports. Be careful and prudent. I'm a big guy and I've been hassled there more than once while p/u or dropping off friends...