To a sweaty-palmed teen-ager from the suburban Peninsula, uncertain whether an evening at San Francisco's Broadway cabarets had made the proper impression on his date, the Embarcadero Freeway was always a godsend.

On the drive home, it took the motorist out of the glare of the city's neon fleshpots, up through the air above the waterfront and into a fairyland of fog, softy lit bridges and pitch-black Bay. The glowing clock of the Ferry Building jutting out of nowhere to the right of the elevated road became London's Big Ben, the high school boy's Volkswagen seemed a magic galleon, the wide-eyed girl beside him was Wendy and he was Peter Pan.

No race romanticizes the modern American freeway more than native Californians, who often think of their multilane roads as Mark Twain once thought of the Mississippi.

Oddly enough, the San Francisco Board of Supervisors did not consider that before hatching a plot to make this the first California city to tear down a freeway. They met this week to consider a plan to tear down the skyway over the Embarcadero, the waterfront area. Some of them enthusiastically called this "the most significant decision the board is going to make in this decade."

Many San Franciscans proudly consider themselves closer to the East than the West. They nurture an affection for labor unions, Democrats and public transportation that seems daft to Californians in the suburbs of the Peninsula and points south.

The supervisors thus plunged ahead with their scheme to write off the waterfront highway as an annoying eyesore and to replace it with a pleasant, tree-lined, ground-level boulevard bisected by rail transit lines.

Besides removing the 1.2-mile elevated freeway, once planned as the beginning of a connection between the city's two great bridges, the project would eliminate an uncompleted highway stub designed to connect Interstate 280 to the San Francisco Bay Bridge. New bridge off-ramps would be built to compensate.

The environmental-impact statement, weighing 3 pounds and running 1,000 pages, cost $1.7 million and concluded that the job could be done for $171.2 million, most of which could come from the federal government.

Even though 60,000 vehicles use the freeway every day, the planners insisted that their adjustments would mean no more than three extra minutes for a motorist traveling from Oakland across the Bay to San Francisco's downtown financial district. And of course being San Franciscans, they emphasized the esthetic advantages of ridding the world of the double-decked freeway.

"It is ugly," board President John Molinari said. "It was a mistake when it was built, and now is the time to rectify the mistake."

The freeway's squat pilings, once a favorite target of the San Francisco Chronicle's political cartoonist, do lack grace. Northbound lanes burrow through a dark, covered cavern, and the topside southbound lanes do not quite match the sweep of such classic California interchanges as the transition of eastbound Rte. 134 to northbound Interstate 210 near Pasadena, or the descent of Interstate 405 into the San Fernando Valley, to name two.

Nevertheless, the Embarcadero has for more than 30 years retained that magical capacity to recreate 15 seconds of Disneyland on a grand scale, enough to galvanize any Californian serious about his heritage.

Supervisors in neighboring Alameda and San Mateo counties, the latter the home of that teen-ager who reveled in the Embarcadero Freeway's delights, sadly shook their heads at the lunacy of the San Francisco scheme and voted to oppose the demolition. Members of the state's transportation commission grumbled, saying they would never go along.

Then came a surprise as the San Francisco supervisors discovered that even their own constituents were a little upset.

Rather than just destroying the view of the waterfront, legendary newspaper columnist Herb Caen said, the freeway had added some scenic wonders. Supervisor Quentin Kopp, totaling his weekend phone calls on the issue, found 50 opposed to the demolition and only four in favor. What was the point, many asked, of spending millions to tear down a freeway just so the few people living on the waterfront could have a better view?

Supervisor Carol Ruth Silver noted the sudden outpouring of opposition and plaintively argued that "the Embarcadero Freeway is one of the smallest parts of this project." The real thrust of the idea, she said, is to boost "public transportation."

The supervisors have agreed to delay their decision until late this month so a public hearing and perhaps more talks with the city's neighbors can be held. Could demolishing a freeway cut too deeply into the web of memories, dreams and habits that define any culture, even one as allegedly elastic as that of California?

"I think the public needs more education, and we need more education," Supervisor Nancy Walker said.