PARIS— EVERYBODY knows that France exports wine, cheese and fashion. But toll booths?

''Very few private toll road companies are successful, but if the customer is pleased, he'll pay gladly,'' said Alain Estiot, vice president for international activities at Cofiroute, the biggest French private highway operator. He is also deputy managing director of an experiment in Orange County, Calif., to privately finance road construction by building pay lanes down the median of a freeway.

The project, for which Cofiroute provided technological knowledge and $135 million in financing, lets motorists pass from the toll-free lanes to the pay lanes with the help of an automated toll-collection plan much like E-ZPass, a system that is increasingly popular in the eastern United States.

In a further innovation, Cofiroute introduced different rates according to the time of day and day of the week, a system now being studied by other toll-road operators, including the New Jersey Turnpike Authority.

The highway -- built on the Riverside Freeway, or State Route 91, on a stretch known for gridlock -- is called 91 Express Lanes. It is the first in the country to compete with an adjacent free public road, and Cofiroute is so far the only European concern with such a private-road investment in the United States.

The company's revenues from toll receipts on the highway are expected to be $20 million for 1999, the fourth year of the system's operation, up from $6.5 million two years earlier.

That is a drop in the bucket of the company's total annual revenue of about $750 million. But the project is a sign of restlessness in the age-old business of building and operating highways, as governments run out of money for such enterprises and private companies take up the slack.

Cofiroute, for instance, is now building 10 miles of double-decker tunnel to close a gap in the western part of the beltway around Paris. It is also building French parts of a key east-west route across Europe and of a north-south highway that will let travelers from, say, Britain or the Netherlands reach the French Riviera or Spain more quickly.

The California project also illustrates how companies that build and sometimes operate roads are casting about for new sources of revenue and new ways to enhance traditional sources.

In Europe, the trend is spawning investment opportunities, as private and government-owned highway operators begin to sell shares on the stock market. Cofiroute is wholly owned by several French banks and construction concerns, but other companies, like Brisa Auto-Estradas de Portugal S.A. and Autopistas del Mar Nostrum S.A. of Spain, have been taken public in recent years.

Last month, in the biggest such offering yet, Italy sold off virtually all the shares in its national highway management company, Autostrade S.p.A., for almost $7 billion. (The remainder, less than 5 percent, will go to management in the form of bonuses.)

In the United States, there have been no similar privatizations, but interest in private road financing is widespread.

Neil D. Schuster, executive director of the International Bridge, Tunnel and Turnpike Association, an industry group based in Washington, said there was a ''recognition that there is not enough money'' for governments to finance road upkeep and new construction. With private companies willing to play a role, he said, governments are increasingly asking, ''Why not let the private sector become involved?''

Cofiroute's entry into the United States road market came after California enacted legislation in 1989 authorizing pilot projects in which private companies could demonstrate their ability to finance and operate highways.

Cofiroute's partners in in the venture, called the California Private Transportation Company, are Level 3 Communications, a former subsidiary of Peter Kiewit Sons, and Granite Construction. The partners were stymied last month in their efforts to reap a $90 million profit by selling the toll road to a nonprofit company.

The dearth of other projects, industry experts say, is a result of many factors, including government delays in studying pilot projects and enacting enabling legislation, as well as the increasing availability of less radical cost-control measures, like E-ZPass. For its 10-mile stretch of highway in California, Cofiroute imported from its French operations a system of drive-through tolls with variable rates based on studies of traffic patterns.

Cofiroute and other highway companies are not only operating and financing roads in Europe; they are also designing and building them. In Spain, for example, private companies, including Autopistas del Mar Nostrum, are finishing the beltway around Madrid.

''Spain is still underdeveloped in terms of road infrastructure,'' said Conor O'Shea, an analyst at Paribas Securities in London. And Portugal, he said, lags behind Spain.

In Eastern Europe, where road construction languished under Communism, private financing and toll collecting are seen as the sole means of supporting badly needed construction.