When we wrote two weeks ago about the escalation of air fares between Philadelphia and Boston, several readers of the Road Warrior blog (http://go.philly.com/roadwarrior) told us what they like about taking the train. Here's an excerpt of one comment:

"I've taken far more Amtrak trips up and down the coast lately. The travel time isn't that different, once you include ground-stop delays, security hassles, and parking/rental car issues. They drop you off in the middle of town. The seats are far wider than anything on a CRJ/ERJ/reconfigured coach class 737/A32x [Those are all airplane models.] And, you have 110v power at every seat."

The traveler also cited the cost of a round trip on US Airways between Philadelphia and Hartford, Conn., as an example of what a rail passenger could save. If you had to buy an airline ticket today for travel tomorrow, you could pay $600 to $950. Amtrak's coach fare up and back could be as little as $128.

For many business trips, of course, Amtrak (www.amtrak.com) isn't a practical alternative. While a round trip between Philadelphia and New York, Washington, and a few other nearby cities is easy to do in a day, Philadelphia-Boston takes about six hours each way. Amtrak in the Northeast Corridor isn't cheap, either, especially if you use the slightly higher-speed Acela trains.

A small number of business travelers who are afraid to fly or who just love riding trains use Amtrak for longer, overnight trips. Between Philadelphia and Atlanta, Chicago or Jacksonville, Fla., for instance, you can leave in the afternoon and arrive the next morning. If you want a good night's rest and a shower in the morning, however, you need to use the first-class sleeping-car service, which will probably exceed the cost of flying.

Another consideration when using Amtrak is its on-time record. While it's usually better than the airlines in the Northeast Corridor, it's worse than the airlines on many long-distance trains.

An economical and practical way to include Amtrak as part of a long-haul trip is the combination of air and rail service offered by Continental Airlines at its hub at Newark Liberty International Airport. Under this code-sharing arrangement, you buy a single ticket from the airline for a train ride from 30th Street Station to the Newark Airport rail stop, where you hop a people mover that takes you to the terminal to catch your flight. Continental often has the lowest fares between Philadelphia and many places to the west using the combination.

The possibility of mergers of major airlines, which we wrote about last week, is a topic of great concern for those who work in the industry and, based on your comments, to some of you. You can expect a steady stream of news about "consolidation" in coming months, in part because some airline officials aren't hesitant to talk about it, as long as their carriers aren't involved in a merger at the moment.

US Airways chief executive Doug Parker, when asked about mergers during the airline's quarterly conference call last week, said his team believed they were inevitable. He called the arguments for one big carrier merging with another "compelling," because combining their operations allows for deep cuts in capacity, or the number of available seats for sale.

Of course, fewer available seats also means the merged company would probably need fewer employees and would be able to raise fares on many routes where competition is limited.

Another interesting Parker comment - and a view shared by many industry analysts and officials - is that airlines that want to merge will try to get the process going by February.

That's because they want the required antitrust review by the U.S. Department of Justice to start while the Bush administration is in office. A new administration, Democratic or Republican, might not be as receptive to the prospect of three giant airlines controlling much of the business as the Bush team is perceived to be.