If you're traveling to or from another country, train service can be just as economical as bus travel, if not more so. The largest international bus operator is Eurolines France, whose main terminal is in the Parisian suburb of Bagnolet (a ½-hour métro ride from central Paris, at the end of métro Line 3). Terminals are also located at Charles de Gaulle Airport, Porte de Clichy, and Porte de Charenton. Eurolines links scores of European destinations, with fares that vary greatly depending on where and when you travel. It will take you about 8½ hours to get from London to Paris, and a round-trip ticket will cost €34 to €49. Other Eurolines routes to or from Paris include: Amsterdam (7½ hrs, €76); Barcelona (15 hrs, €117); and Berlin (14 hrs, €91). Economical passes are available—a 15-day version costs €215–€355, and a 30-day one costs €320–€465. These offer unlimited coach travel to all of Eurolines's European destinations.
France's excellent train service means that long-distance bus routes within France are rare; regional buses are found mainly where train service is spotty. The service can be unreliable in rural areas, and schedules can be incomprehensible for those who don't speak French. Your best bet is to contact local tourism offices.
Eurolines . 08–92–89–90–91; 01–41–86–24–21; www.eurolines.fr.