Pros: City-center to city-center convenience, high-speed routes, a system of discount passes unsurpassed anywhere, opportunity to meet Europeans
Cons: Increasing prices on many routes, limited ability to explore the countryside, susceptible to labor slowdowns and natural disasters
If you book the trip between Brussels and Paris, don't expect to see much of the countryside.
Trains hit 300 kilometers/hour (180 MPH) on that route, and much of what you see from your window is a blur. But you can step on a train platform in one city and step off in the other locale in a mere two hours. Try that in an automobile and you'll break your neck along with a lengthy list of traffic laws.
On the train, a well-placed overnight on occasion can save money on hotels and allow you to be the first tourist to arrive in a new city (first in line, first to reserve budget hotel rooms and first in line for breakfast). Warning: for the comfort of you and your travel party, consecutive overnights on a train are not recommended.
The convenience and comfort associated with European trains make them a favored choice of many travelers. If it sounds like a safe and uncomplicated choice, it's not.
The first complicating factor is the time frame for using passes. Some are consecutive, meaning you a get a set number of days to use the pass before it expires. Others are based on an expiration date and a number of travel days within that time in which the pass can be used. This can make sense for people who go to a city and stay there for a while.
Individual tickets--especially in first class--can be expensive, but the train option comes with an impressive (and frequently confusing) array of Eurailpass options that can cut the cost significantly.
IMPORTANT: Rail passes must be secured before you leave for Europe. These purchases can be done easily online at vendors such as Rail Europe.
If nine of your 12 days of Europe will be spent in one country, for example, it might make sense to look at Single Country Passes and choose one for your destination. You could pay for point-to-point European rail tickets the other three days.
Still have questions? Try using a tool at Rail Europe called "Railpass Selector: Find the perfect pass." Here you'll find a pass comparison chart, tips to consider before making a choice and the most popular passes (sometimes an indication of the most practical as well).
Trains and automobiles were the staple choices for European travelers in previous generations. Airfares within Europe were outrageous and airport services limited. That is no longer true. In fact, Europe has become the world's budget airline leader.
More information: Consider discount airfares as you travel in Europe.