It was no mirage, this movable feast for the eyes. More Raleighs, Schwinns and Shoguns were wheeling along University Avenue than Volvos, Vegas and Volkswagens. Citizens here, head-over-wheels- in-love with the world's most efficient form of mechanical transportation, have made their city the bicycling capital of America.

Bicycles outnumber cars three to two. About 100 miles of bike routes serve the 170,000 Madisonians who pump around on 150,000 cycles. More than 30 bike dealers and repair shops are listed in the Yellow Pages. In 1984 the city government employed 11 bike cops who put the brakes on lawbreaking cyclists for $31,000 worth of fines. Ten percent of Madison's workers commute by bicycle, and 50 percent of the 42,000 students at the University of Wisconsin pedal to class.

On University Avenue, a one-way crosstown expanse that runs west through the campus, the numbers are one astonishment. The other is the peaceful coexistence between cyclists and motorists. Only lambs lying down with lions offer tranquillity to rival the harmony of bikes and cars sharing space, rather than swerving for it.

The city's traffic engineer used his head to get people to use their wheels. From sidewalk to sidewalk, University Avenue is 66 feet wide. The eastbound bike lane takes 8 feet of curbside space. It is protected from oncoming traffic by a raised 3-foot median. Cars, trucks and buses then have three lanes of 11 feet each, after which is an 8-foot lane for westbound cyclists. The last lane is for buses and right turns.

Parts of Madison, with its bulky homes, have the rumpled look, as if the town's architecture took its dress code from the sweaters and corduroys of the professors. The bicycles fit in naturally with the relaxed academic pace. As a bicycle commuter who luxuriates in 50 miles a week of the commonwheel, I was curious how Madison had come upon its rationality. A visit to Steve Berchem, the city's bicycle-safety person, provided some answers.

Berchem spoke about State Street, a thoroughfare that runs slightly less than a mile from the Capitol to the campus. Only pedestrians, bicycles and buses are allowed. The addiction to cars, Berchem said, was not easily overcome. There's another way of phrasing it: the withdrawal pains brought Madison to the brink of the Great Anti-Car War. In 1972, the city council experimented for six months with a carless State Street. It decided that Madison wasn't ready for that kind of radicalness.

The politicians hadn't counted on the populist sentiment that led to an economic boycott of merchants along the street who favored cars. Nor did they understand the power of student demonstrations. This was Madison in the early 1970s where a day without a protest was like a Wisconsin dairy farm without a cow.

The students, leading the bicycle revolution, prevailed. Today the street supports a mall that is a model of carefree and car-free serenity. By coincidence, 1972 was the year that the Organization for Economic Cooperation and Development surveyed several cities that had created traffic-free zones: "In Vienna, shop owners reported a 25 to 50 percent increase in business the first week after the traffic ban went into effect last December. In Norwich, England, all but two shops in the exclusion area did more business. Some increase has been reported to be between 15 and 35 percent; Rouen, in France, between 10 and 15 percent."

Bicycles represent a positive transit system, while cars are a negative pollution system. The remarkableness of Madison bicycling is that citizens pedal through life on weekdays the way New Yorkers, Chicagoans and Washingtonians do on weekends. Leisure time can be all the time. Big-city people have yet to figure out that the relaxed pace of bicycling doesn't conflict with mobility.

Whenever I have given in to moments of wild fantasy and suggested to friends that they commute by bicycle, the replies are models of contradiction. Bicycling is too slow, they say. Oh? What's slow about 15 miles an hour on the straightaways and 10 mph uphill? These are speeds by which bicyclists roar past morning and evening car-stall hours.

If 15 mph is slow, so what? It's the loveliest of speeds, if getting the caress of God's seasons and the feel of your own muscles is a luxury. The story of Madison's bicycles is a tale of people who think legpower is superior to horsepower. In "The Man Who Loved Bicycles," Daniel Behrman writes that, "The bicycle insinuates itself unseen into the innermost tissue of a large city where there is so, so much life that cannot be sensed through a windshield."

If more persuasion is what you need, come to Madison for the joys of the slow lane.