EXPO 86. If long lines are any indication, this may be the most successful North American exposition in more than 20 years

For half the summer, Canada has been reminding the world it takes more than Belgian waffles and a monorail to make a world's fair. After three US-based, ``world'' expositions of dubious distinction (Spokane, Wash., 1974; Knoxville, Tenn., 1982; New Orleans, 1984), Canada's Expo 86 appears to be the only one with enough quality, quantity, and diversity to deserve the title. When the fair opened with great expectations on May 2, the only question for Canada seemed to be: Are there enough prospective visitors within striking distance of the Pacific Northwest?

Now, with the fair more than halfway through its 5-month run, the answer seems to be a resounding ``yes.'' Original projections of 13.5 million visits were upped to 18.5 million just after opening day. As of early August, some 12 million people had passed through the turnstiles -- and that was after the fifth rainiest July on record, which authorities say held numbers way down.

The fair has been so popular and so close to its daily capacity that the most telling description of the midway is captured in one word: lines.

``It's a great fair when you get to see it,'' laments 17-year-old Jamais McCullough, who traveled with her mother, father, and younger brother from Massachusetts and bought a $45 three-day pass. ``Many of the lines are one and two hours, which cuts down on how much you can see in a day. I think they got more than they could handle.'' The longest lines snake toward the various Canada pavilions, General Motors' ``Spirit Lodge,'' and the silver-centerpiece building known as Expo Center. Some attractions have no lines, because ticketing is done in advance.

``Pavilions are open at 10, but the brochures don't tell you the tickets go on sale at nine,'' says another fairgoer, from Los Angeles. ``Then they're sold out by noon.''

If all the crowds continue as scheduled through closing on Oct. 13, fair officials project that the Expo will be $76 million in the black -- after a $250 million boost from a British Columbia lottery and $125 million from the federal government.

The success of Expo 86 is the wide-open window it provides into the diversity of Canada's people, climate, landscapes, cities, and technologies.

Because each of the two territories and eight provinces (Manitoba and Newfoundland didn't participate) has its own pavilion packed with movies, exhibits, and live presentations, the fairgoer comes away with far greater insight into the second-largest nation on earth -- and its 25 million people, British and French heritage, and myriad Indian tribes. There is no equal time granted to national foibles; true to exposition form, this is ``a celebration of unity, history, and progress.''

En masse, though, the Canadian exhibits explode the clich'e-ridden notions of an ice-filled climate, dominated by red-suited Mounties, hockey-players, and northern trappers. Canada is seen here as well with leading universities, research and manufacturing facilities, artists, performers, other world-class sports leagues -- and summer weather that permits beachgoing on thousands of lakes. One-sided perhaps, but still eye-opening.

The largest attraction of Expo 86 is Vancouver itself, the surrounding Coastal Range Mountains, pristine air, and ocean inlets. Seasoned fairgoers are calling it the most appealing and dramatic backdrop ever.

Beyond that, the site itself is well built (far more so than New Orleans), well kept, and -- remembering the undigestible size of larger fairs of yore -- manageable in scale.

To heighten the sheer enjoyment of fairgoing, organizers have spent $60 million on entertainment alone. All along the midway are live bands, comedians, and individual performers of all kinds.

Special theme weeks are spread throughout the fair. Two most recent successes: ``Air Fair '86, Aug. 1-10, during which all manner of historic aircraft flew over the fairgrounds, 40 at a time; and Ships of the World, bringing tall ships, ferries, kayaks, yachts up False Creek Inlet next to the midway. British Columbia Day, Aug. 4, saw the record attendance of the fair: 174,709.

All in all, Expo 86 promises a lot and, for the most part, delivers. Success or failure, Vancouver will reap the benefits of the fair site, which will be the start of urban renewal projects leading to housing for 20,000 and jobs for 30,000.

In the meantime, there is a monorail all fairgoers can ride for free. And you can get great Belgian waffles.