Traffic in Times Square seems to be bogging down just at the point where Broadway and Seventh Avenue converge, and pedestrians, transfixed in their tracks, become pigeons for area pickpockets. Small wonder. On the billboard overhead is an 81-by-24-foot image of a strawberry blonde on all fours, clad in a silvery silk shirt and arrestingly tight jeans. The name on the pocket is Calvin Klein, but if the police want to write a ticket for stopping traffic it should go to Patti Hansen, the most wanted model in America.

In an age of small cars, tight money and diminished expectations, Patti is a smashing reminder that bigger can be better. Her 5'9" height is quite standard for today's mannequins, but at 130 pounds she's got a sexy extra 15 pounds of lushness on the competition that is causing a storm on Seventh Avenue. "Patti," proclaims fashion photographer Francesco Scavullo, "makes Cheryl Tiegs and Farrah Fawcett seem old hat."

Indeed, Hansen earns $200 per hour for print and $2,000 a day plus residuals for TV spots—tops in the business. At 23, she already has 72 magazine covers, and on TV she draws the blow-dryer pistols in the cowboy spoof for Revlon's Flex shampoo. Her annual take now approaches $300,000.

Unobsessed by the model's usual narcissistic concerns, Patti neither exercises nor dotes over her diet, skin or sleep. She often loads up on junk food, and when she feels fat simply goes on a yogurt binge for a week. She'll run into a store and blow $100 on skin moisturizers, then never use them. "I have such different moods," she says. "Sometimes I'll lock myself in my apartment and sleep all day. Then I'll get this mad urge to go out and dance all night at Studio 54."

Work revives her. "I love to be different people," Patti explains. "I don't relate to any of my photographs as Patti Hansen." Particularly a nude beach shot taken by Helmut Newton for Vogue two years ago that wound up instead in the "Celebrity Skin" section of High Society. Patti sued to stop the distribution of that issue—and won a preliminary injunction.

Director Peter Bogdanovich, who once molded another model, Cybill Shepherd, into a movie star, also misread Patti. After she appeared on the cover of Esquire 14 months ago in a vixenish pose for a story proclaiming "the year of the lusty woman," Bogdanovich thought he'd cast her to that type. But he was shocked when she strolled into his office in T-shirt and jeans, several of her young nieces and nephews in tow. Shifting gears, he eventually gave her the role of a cab driver in They All Laughed, which starts filming next month with Ben Gazzara and Audrey Hepburn. Hansen has even been offered a record contract. "How could they do that? I can't even sing," she marvels. "They say, 'Don't worry, we'll just put all this music and things in it.' That's such a cheat," figures Patti.

Born of Norwegian stock on Staten Island, Patricia Elvina Hansen is the youngest of six children. The daughter of a housewife and a bus driver who later opened a hot dog stand near the Staten Island ferry, Patti considered herself "gawky and skinny" as a teenager. No one else did, however, and one day after her sophomore year at Tottenville High, friends of the family sent a fashion photographer they knew to see her. That night they went to a party given by Wilhelmina, herself an ex-model and founder of the second biggest modeling agency in New York. It was Patti's first real date and her first night in Manhattan. "I was really frightened," she recalls, but Wilhelmina signed her immediately and sent her to Julie Britt, then fashion editor of Glamour. Britt took one look and declared, "You're going to be the new image."

Patti, then 16, never completed high school—a decision she now regrets. To compensate, she is now hacking away at a reading list heavy on Hemingway and Fitzgerald (her one hang-up: "I hate sad endings"). Last year Patti took acting lessons in California, then returned to New York to study with the formidable Stella Adler but dropped out because "she scared the sh-- out of me."

Restoring her optimistic outlook is usually as easy as visiting her family or flying to the Bahamas. In her small apartment on lower Fifth Avenue, Patti is constantly changing the decor. One year-round decoration: a lighted Christmas tree. On the road, she takes a mound of scarfs with her to throw over hotel room lamps to dim the light for a more homey effect.

She is "handled" by four agent types, a lawyer and an accountant, but there is no John Derek on the horizon. Hansen has never had a resident boyfriend and is determinedly unattached. "I'm afraid to lose anybody," she explains. "I don't even want to have animals." Her escorts include leather designer Billy Tsutsos and musicians, because "they have such crazy energy." One important fashion editor warns that "Patti is in a devouring business, and people worry that she'd better get her act together or she'll burn out at 25." Photographer Scavullo is not quite so pessimistic. He describes Patti Hansen as "the Marilyn Monroe of the '80s."