Alexandria officials say they hope new taxicab regulations that go into effect next month will produce a gradual turnabout in a taxi industry that has acquired a reputation as one of the worst in the Washington area.

"When visitors come to Alexandria," said Deputy Police Chief Orlen Justice, "the first thing they see is our cabs. And when they the drivers are less than courteous or overcharge, that gives our city a bad name."

Alexandria's taxi troubles are rooted in the city's lax regulation of cabs and the fact that many of the gypsy cabs operating out of National Airport carry Alexandria licenses.

For years, critics have complained that many of 567 cabs certified to operate by Alexandria are registered in the city only because it is easier to win certification there than in any other Washington jurisdiction.

Critics charge that this has led to Alexandria cabdrivers who don't even want to go to Alexandria from National Airport--a modest fare compared with a trip to Washington or Reston. Alexandria's only hack inspector receives hundreds of complaints about city cabs for grossly inflated fares and drivers who threaten and intimidate their passengers, authorities say.

Last month, after weeks of debate, the City Council unanimously approved 11 pages of amendments to the city's taxicab code. Most of the changes, all of which pertain to how cabs are certified, are designed to give the city more authority to regulate the numbers of taxis certified in Alexandria.

Besides the hundreds of cabs certified already, applications are pending for another 90. Mayor Charles E. Beatley Jr. and other officials have complained to police that that is too many.

Even some taxi industry officials support the new code. "It will strengthen the industry as a whole," said Robert Werth, general manager of Alexandria Diamond Cab. "It will bring stability to the industry."

City law now specifies that Alexandria taxis must do at least 51 percent of their work in the city, but Beatley says 90 percent of the city-certified cabs do most of their work at National.

A major section of the new code, said Assistant City Manager Michele Evans, is a provision that orders City Manager Douglas Harman each year to review the city's taxi needs and approve certification applications on the basis of the review's findings. Applicants must explain why the city needs another cab certified.

Hopes are that the hack inspector, previously responsible for certifications, will be able to keep a closer watch on Alexandria cabs. In addition to the annual review, Evans said, the code will limit certificate applications to between May 1 and May 10. And they will only be reviewed once a year, unlike the present procedure that accepts applications year round and reviews them monthly.

Evans said the code will give the city a chance to weigh its need for taxis against industry demands to increase their fleets. She said it is unlikely that the number of city cabs will grow as it has in recent years.

The new measure, however, should not affect current certificate holders because they will only have to seek an annual renewal, a much less exhaustive process.

"We hope to stabilize the system over the next couple of years," Evans said.