Q. I have been tracking fares from Chicago to Philadelphia, New York and New Jersey for the last few months. While I frequently see great deals to New York and New Jersey, in fact some amazing deals, I have yet to see an actual deal on flights to Philadelphia. I don't understand the discrepancy. The airports are only a couple hours apart and I could easily fly into Newark or New York instead of Philly so why is it so much more expensive to fly there? This is driving me a little nuts!

A. Part of the reason is that Philadelphia is a US Airways "fortress hub," meaning that US Airways is a predominate carrier there. True, Southwest now serves Philadelphia, and that has helped a bit, but New York's two major airports (LaGuardia and JFK) are served by almost every U.S.-based airline. Newark is a Continental Airlines hub, but Southwest recently started flying there and introduced some amazingly low airfares. One workaround is to fly into Newark and hop on the train to get to Philadelphia. The trip takes about an hour. You can also take one of the many discount bus services, such as Bolt Bus, between the two cities.