8:59 p.m. EDT March 27, 2014  Which is the better way to travel: by train or by plane? The answer depends on dozens of variables, including geography, cost and time.

Between certain cities — say, Philadelphia and Baltimore — Amtrak is the logical choice. On longer routes, flying makes more sense. But many other itineraries offer pros and cons for both trains and planes, particularly when total trip length is considered, alongside total pricing inclusive of all fees and extras.

That's why we examined six busy routes throughout the country where both modes are viable options, in order to draw head-to-head comparisons: Boston-New York; New York-Washington, D.C.; Miami-Tampa; Chicago-St. Louis; San Antonio-Dallas; and San Diego-Los Angeles. We also varied the travel times and booking windows, ranging from just one day to three weeks in advance. The chart below points up some striking advantages and disadvantages.

Fare comparison

On all six routes, Amtrak was cheaper than the cheapest available airline alternative, which we found by searching airline sites, as well as Kayak and other metasearch sites, such as those we examined here. In the most dramatic examples, the train was $435 less expensive between Boston and New York and $378 less between New York and Washington. Both routes are served by hourly air shuttles.

Amtrak's price advantage was less dramatic on the other four city pairings, ranging from $115 to $138. As detailed below, however, these airfares do not include fees for baggage and other services, nor do they include ground transportation. So between Miami and Tampa, for example, the lowest airfare was $197 on American, but one round-trip checked bag would add $60 and ground transport would add about $47, for a total of $304.

It's also worth noting Amtrak was cheaper regardless of how far in advance we sought to book.

Travel time comparison

Conversely, on all six routes the cheapest airline was quicker — often much quicker. In the most dramatic example, between San Antonio and Dallas, the time savings on United totaled 14 hours and 30 minutes, not counting ground transportation, which would add 50 minutes. (For $11 more, a round-trip on Southwest would shave another one hour and 50 minutes.)

What's clear is that on many routes, only those who desire to see the countryside or who fear or dislike flying would justify allotting so much additional travel time for Amtrak. But on many other routes, the total door-to-door trip time and convenience factor could tip the balance for rail travel.

Total travel time and cost

In nearly all cases, Amtrak provides inner-city service via old-school train terminals, so for many travelers, getting to the station may be easier and cheaper than reaching an airport. Meanwhile, airport proximities to downtown areas and taxi costs can range dramatically.