Swift, flamboyant bicycle couriers are a familiar sight in this town of deadline chasers, traffic jams and limited parking. Bicyclists deliver 8,000 packages in an average working day downtown, where they make much better time than cars -- in part because they flout traffic laws.

Supporters of a bill that would put new restrictions on bicyclists, including licensing and safety tests, hope the measure will put a brake on "kamikaze" messengers who speed the wrong way on one-way streets, run red lights, zoom on and off sidewalks and career into pedestrians.

The bill, passed by the D.C. Council this month and signed by Mayor Marion Barry, would require the city's 400 bicycle couriers to pass a safety test, pay an annual licensing fee of up to $50, carry a permit and display a sign with an identification number. Fines of up to $50 would be imposed for violations, and licenses could be revoked for nonpayment. The measure, subject to congressional approval, is slated to take effect in the fall.

Some couriers readily admit to breaking traffic laws but say their offenses are exaggerated and that they do not generally endanger pedestrians. They say they are forced to swerve on a moment's notice for a number of reasons: potholes, doors swinging open.

"We ride the way we ride to survive," said Larry Cooley of Omni Couriers.

The conflict among the commercial bicyclists, pedestrians and cars has turned into a bitter war that led D.C. Council member Nadine P. Winter (D-Ward 7) to introduce the bill. According to a D.C. police report, no one has been killed in a bicycle-pedestrian collision here, but more than 25 D.C. pedestrians were seriously injured by bicycle messengers in 1986.

In a report on the bill, Winter said, "Bicycle messengers have hit and severely injured pedestrians," leading to "a sense of frustration" for police and pedestrians who cannot identify a bicycle courier.

Linda Keenan, chairman of the D.C. Bicycle Advisory Council, told the D.C. Council last fall that serious traffic violations by bicycles downtown have become "a daily occurrence." Low fines ($5 for any violation) and lack of law enforcement are partly to blame, she said. According to Bicycle Advisory Council coordinator Tom Pendleton, a bill is being drafted that would raise some fines to $25. The Bicycle Council advises the city on matters related to bicycling.

D.C. law does not require couriers to wear identification, and the Washington Metropolitan Courier Association estimates that less than 9 percent of an estimated 175,000 commercial and noncommercial bicycles in the city are registered. D.C. law requires registration of all bicycles.

Some local couriers, meanwhile, said last week that they oppose the bill. "There are a lot of loopholes," said Andre Bears of Omni. He wondered how police will discern couriers from bicycle commuters, and if the distinction is fair. "What happens if the commuter races and runs lights, too, and I get a ticket and he doesn't?"

David Isler of Messenger Express says pedestrians should be made to toe the line as well. "Most people in D.C. walk against traffic lights and don't look where they're going. They do the same things as couriers," he said. Couriers also object to the annual fee and, in an occupation that flaunts individuality, to wearing a number.

The chief problem with the law, these couriers said, is that in this business, time is money. According to courier companies, most bicycle messengers work eight to 12 hours a day during the week and are paid on commission. Courier companies charge their customers $4 to $6.50 per run; the couriers keep about half that amount.

A courier company manager, who asked not to be identified, said, "The bottom line is that if they stopped at every red light and obeyed all the traffic rules, they wouldn't make any money. It's $600, $700 {a week} if they cut corners; $400 if they don't."

Martin Baumgart of Messenger Express, which employs 20 bicycle couriers, said, "Anybody who's making any money at this -- that is, over $20,000 a year -- is working 10 to 12 hours a day. Some couriers make $40,000 a year, though -- I've paid weekly checks totaling over $1,000."

Some couriers say the law would have little effect. Liz Bullock of Allstate Couriers said she is a cautious rider but "I'll probably be a little more cautious. For the most part, I'll continue what I'm doing. I'm curious to see what I can continue doing."

Representatives of some of the 75 courier companies in town that use bicyclists are philosophical about the legislation, saying it will not significantly affect business. Allen Atkinson, general manager of Omni, said, "It's all going to fall ultimately on the couriers."

The law is not intended to promote citizen reports, which "smacks of vigilantism," Pendleton said, but should ease enforcement of existing laws. Couriers probably would not be stopped at random, but if police officers stop them for another offense, they would check for a permit. "There's been little incentive to comply with bicycle traffic laws," he said.

Capt. David Baker, commander of the D.C. Police Traffic Enforcement branch, said the new law would step up enforcement. "From an enforcement point of view, bicycles present a unique problem -- they're very difficult to stop . . . . Any law that strengthens identification increases enforceability."

However, one police officer commented: "The regular street officers don't have time to mess with it. We're a thousand men short now. Our crime has doubled since last year -- you think we're going to worry about bicyclists running red lights? I wouldn't even look at them -- that's not what I'm here for. In 17 years on the force, I've yet to stop a bicycle. If I work 17 more, I won't stop one."

New York City and San Francisco have bicycle messenger identification programs. In New York City, the state Supreme Court overturned a law that would have barred the city's 5,000 couriers from major downtown streets.

"If the licensing process here is going to get rid of the few bad apples, I'm all for it," said messenger Joseph Muise of Executive Couriers. "I don't really see many complications arising from the licensing process, but to tell you the truth, it's just a hassle. The majority of couriers are not a public nuisance."