For those who make journeys across the world, the speed of travel today has turned the countries into a series of villages.Distances between them appear no greater to a modern traveler than those which once faced men as they walked from village to village. Jet planes fly people from one end of the earth to the other, allowing them a freedom of movement undreamt of a hundred years ago. Yet some people wonder if the revolution in travel has gone too far. A price has been paid, they say, for the conquest   of time and distance. _  .  The boat offers leisure and time enough to appreciate the ever-changing sights and sounds of a journey. A journey by train also has a special charm about it. Lakes and forests and wild, open plains sweeping past your carriage window create a grand view in which time and distance mean nothing. On board a plane, however, there is just the blank blue of the sky filling the narrow window of the airplane. The soft lighting, in-flight films and gentle music make up the only world you know, and the hours progress slowly. Then there is the time spent being "processed" at a modern airport. People are conveyed like robots along walkways; baggage is weighed, tickets produced, examined and produced yet again before the passengers move to another waiting area. Journeys by rail and sea take longer, yes, but the hours devoted to being "processed" at departure and arrival in airports are luckily absent. No wonder, then, that the modern high-speed trains are winning back passengers from the airlines. Man, however, is now a world traveler and cannot turn his back on the airplane. The working lives of too many people depend upon it; whole new industries have been built around its design and operation. The holiday maker, too, with limited time to spend, patiently endures the busy airports and limited space of the flight to gain those extra hours and even days, relaxing in the sun. speed controls people's lives; time saved, in work or play, is the important thing--or so we are told. Perhaps those first horsemen, riding free across the wild, open plains, were enjoying a better world than the one we know today. They could travel at will, and the clock was not their master. What is the main idea of the passage?
Air travel benefits people and industries. Train Travel has some advantages over air travel. Great changes have taken place in modern travel. The high speed of air travel is gained at a cost.