Newsweek has some articles about cheap buses in the USA
http://current.newsweek.com/budgettravel/2008/05/buses_east_coast_welcomes_mega.html
Bus trips between Northeastern cities now cost as little as $1 each way through Megabus.com, which is a sister company of Gray Line New York Sightseeing and is owned by Coach USA. The company uses brand new buses with comfortable seats placed high for a sight-seeing feel.
Today, Megabus launched service the between New York and Boston, Washington, Philadelphia, Baltimore, Buffalo, Atlantic City, and Toronto. As Erik Torkells blogged in advance, "there will be a handful of $1 fares, though they must be purchased very far in advance, and of course prices go up the nearer you get to the date of departure."
Megabus website
There are also other discount bus companies springing up, such as Greyhound's Boltbus and DC2NY.
This should have a positive effect on hostels in the USA if the coverage is wide enough.
Log in to join discussion