(FORTUNE Magazine) – Most cities in Western Europe and North America-- including London, Montreal, and West Berlin--ripped up their trolley tracks in the 1950s and 1960s to make way for cars and buses. But a new generation of trams is making a comeback. Call the new edition, more quiet and sleek than its ancestors, "light-rail mass transit."

The modern systems are all the rage in France. Rouen and Strasbourg got on board late last year, joining Saint-Æ’tienne, Grenoble, Lille, and Nantes, all of which built trolley systems in the past ten years. "The tram no longer makes anybody think of the 19th century," says Alain Grandel of Banque Paribas, which helped finance Rouen's system. "For most cities it's the most modern, cost-effective, and ecological form of public transportation."

Run on electricity, trams emit no diesel fumes, as opposed to buses, which also clog center-city traffic. And trolley lines are cheaper to build than subways. Rouen's grid of 22 stations and seven miles of new track cost only $600 million, even though 1.3 miles of track are underground, requiring expensive tunnels. Systems built on existing railroad rights of way can be even less expensive, as low as $10 million a mile.

Leading suppliers like GEC Alsthom, which designed the sleek Rouen system, and Matra are steering technology into the future. Trolleys on Matra's VAL system, in place in Lille, run fine without a driver. Now all we need are cars that do the same. (See Technology for what's ahead for autos.)

- William Echikson