The scene lurks at the back of many women's minds.

She's driving alone one night when her car breaks down. She can't fix the car. The only person she'll trust right now is a police officer, but she doesn't know how long it will be before one comes along. Does she sit tight and wait for assistance, or does she risk getting out, walking or hailing a car for help?

The Alexandria Office on Women says she should stay in the car. The office also wants women -- or any motorist, for that matter -- to have a "Please Call Police" emergency banner that can be displayed in their car's rear window. The banners, sold by the Office on Women for $3, are intended to make it easier for people to get help when they have a problem on the road.

"The phone has been ringing off the hook" in the wake of a radio spot publicizing the banners, said Sue Carperelli, coordinator of the Office on Women's health and safety program.

She reported getting many calls during the day from women wanting to buy the banners for their daughters and granddaughters. Husbands have been calling, too, wanting to buy the banners for their wives, said Patricia Toste, director of the Office on Women.

People have become more aware of the danger of seeking help from strangers, and Carperelli hopes the banners will help people feel less vulnerable on the road. "We want to encourage them to call the police rather than rely on strangers," she said.

The Office on Women has sold 200 of the banners during the past year, 56 of them last month. Carperelli said she expects sales to continue at a rapid clip the rest of this year.

In the Washington area, with its high percentage of working women, "everybody travels," Carperelli said. Toste reports reading news stories almost daily about women who are mugged or raped on the side of the road.

The banners give passers-by a chance to become indirectly involved by calling the police, said Toste, who owns a banner and bought one for her mother. "I've passed two people with them in the last two years," Toste said.

Lucy Crockett, public information officer for the Alexandria Department of Public Safety, said that while the department is not involved in the banner program, it fully supports it.

"I think it's an excellent idea," said Elinore Lent of Fairfax County's Commission for Women. She added, "It's something we might consider doing."

Alexandria is the only Northern Virginia jurisdiction offering the banners.

The proceeds from the banner sales are used to purchase materials for the Office on Women's rape-prevention program, and to supplement funds for direct counseling services. Alexandria buys the banners from a rape prevention group in California.

The message, "Please call police," is spelled out in nine-inch-high pink fluorescent letters and is intended to be placed in the car's rear window. Adhesive tabs allow a motorist to affix the banner to a window without leaving the car.

Carperelli said that because of recent demands, the staff cannot keep up with telephone orders. The banners can be obtained by mailing a check for $3 to The Alexandria Office on Women, 405 Cameron St., Alexandria, VA 22314.