Commuters in the Washington area waste more time behind the wheel than most Americans. So it's not surprising that someone has found a way to make money off us angst-ridden, car-bound consumers.

Two retail chains, Talking Book World and Earful of Books, plan to dot the area with stores that sell and rent audio books only. You're stuck in traffic, they figure, so why not calmly listen to a good book instead of stomping on the accelerator or giving the well-known digital salute to another motorist?

"All of a sudden you're looking forward to a delay," said Wendy I. Kirchick, co-owner of the new Talking Book World store in Rockville. "You get there and then you idle."

In recent years, audio books have emerged from the back corners of bookstores to become the fastest-growing segment of the industry. Sales of audio books rose about 10 percent to $2.2 billion in 1998, according to the Audio Publishers Association.

The market for audio books keeps getting bigger. Shoppers can now sift through thousands of book titles at online stores such as Amazon.com and the Audio Book Club (www.audiobookclub.com). Soon, customers will be able to use their computers to download audio books onto compact discs.

Encouraged by the growth, big chains such as Barnes & Noble say they are widening their selection of audio books. At the same time, new competition is emerging from smaller chains that hope to carve a niche by providing customers with more titles and the option to rent as well as buy.

The first in the new breed to come to the Washington area is Talking Book World, a Southfield, Mich., chain that opened the Rockville store earlier this month and has signed a lease for another location in Sterling opening next fall. Another retailer, Earful of Books, of Austin, has announced plans to open stores in Rockville, Gaithersburg and McLean next year.

It's no coincidence that the Washington area has a high percentage of voracious readers who also happen to live in one of the nation's worst places to drive. For the fifth year in a row, it ranked as the second-worst urban area for traffic congestion, behind only Los Angeles, according to this week's report by the Texas Transportation Institute. The average driver spent 76 hours, or almost two workweeks, stuck in traffic jams in 1997--enough time to listen to all of "War and Peace."

Seeking a more tolerable drive, many commuters say they have turned to audio books. Pop in a book cassette, they say, and an angst-ridden drive becomes a journey into the world of magic ("Harry Potter and the Sorcerer's Stone"), romance (Danielle Steel's "Irresistible Forces") or self-improvement ("The 7 Habits of Highly Effective People").

Thomas Kelly, who commuted from Dupont Circle to Baltimore until recently, said he began buying short fiction, essays and poetry on tape after growing tired of radio talk shows and what he claims is the "failure of jazz radio in D.C." A good audio book, he said, also keeps him from growing impatient.

"When you're listening to a book, your focus isn't on the rage or stress," said Kelly, a 35-year-old senior associate for a children's foundation. "I don't feel the need to be the one speeding in the right lane. And there's always that worry of getting there too quickly and not having time to listen to the book."

David Moon, a 32-year-old physician from Rockville, said he feels every valuable minute ticking away while he's in his car. Audio books, he said, allow him to listen to the bestsellers he has wanted to read for a long time and fill what would otherwise be wasted time.

"We're always trying to find ways of cheating time," Moon said.

Audio books appeared on vinyl records first, and their customer base included a large number of people with visual impairments, according to retailers and publishers. Long-haul truck drivers and traveling sales associates were among the early adopters of audio books, which until the late '80s featured many motivational and self-improvement book titles.

The introduction of the Sony Walkman brought audio books to the masses. The new portable cassette player allowed voracious readers to listen conveniently to books while jogging, riding the subway and flying on business.

"It made listening portable," said Jenny Frost, publisher of Random House Audio Publishing Group in New York. "The uses changed dramatically. You could take your favorite book anywhere."

The audio book industry responded by improving selection. Today, shoppers can choose among tens of thousands of titles. They can hear John Grisham's "The Street Lawyer" in abridged or unabridged versions, and on tape or compact disc.

Publishers also worked to fine-tune the quality of audio books, often choosing to use actors and professional storytellers instead of the authors.

"I hate to say it because he's dead, but Brandon Tartikoff [former entertainment president of NBC] was the worst I've ever heard," said Paul Rush, president of the Audio Publishers Association and president of Earful of Books. Tartikoff narrated "The Last Great Ride," in which he describe the making of popular TV shows.

Audio books may enhance moods and reduce speeding, but they are not the magic pill for safe driving, according to motorist groups and highway safety officials. They do not keep drivers alert to traffic patterns, and they do not keep people awake. Last year, a tractor-trailer driver plowed his rig into vehicles that had stopped on the Capital Beltway for a Wilson Bridge opening. He had fallen asleep while listening to an audio book.

"We've talked to the sleep experts, and the consensus is that the only things that help are sleep and caffeine," said Stephanie Faul, spokeswoman for the AAA Foundation for Traffic Safety.

Faul also suggests that people driving in unfamiliar places or in nasty snarls hit the stop button before the story gets too interesting.

"If traffic gets bad turn off the radio, turn off the tape, put your sandwich down, put the cell phone down," she said. "You want to be alert."

CAPTION: Wendy Kirchick is co-owner of Talking Book World in Rockville. The Southfield, Mich., chain also plans another location in Sterling.