An Islamic civil rights group said yesterday that Muslim taxi drivers at Reagan National Airport are being denied a suitable place to pray and has asked for an investigation by the U.S. Department of Transportation.

Nihad Awad, director of the Council on American-Islamic Relations, said at a news conference that airport officials have not made accommodations for the drivers, whose religion requires them to pray five times a day. About 70 to 80 percent of the 1,700 taxi drivers who are permitted to pick up passengers at National are Muslim, according to the council.

Awad pointed to a notice posted in March 1998 at the airport's taxicab holding facility--a parking structure where cabdrivers wait in their taxis to be dispatched--that prohibits taxi drivers from using that building "or related facilities to assemble for prayer or for other purposes."

He also said that some drivers were ticketed for "obstructing traffic" when they tried to pray outside their cabs and that some of their prayer rugs have been thrown out by police.

Tara Hamilton, a spokeswoman for the Metropolitan Washington Airports Authority, said there are places at the airport where individuals can pray. But she said that when a group of Muslim drivers has assembled to pray at the holding facility, it has caused traffic problems.

"What we have found is that over time, the drivers have started praying in groups," Hamilton said. "It was a safety hazard. They wouldn't be in their cabs able to move."

Hamilton added that the airport cannot favor one culture or religion over others in its designation of space. Moreover, she said, the taxi drivers are independent operators, not airport employees, who choose the times they want to come to the airport.

Hamilton said airport officials have tried to accommodate the drivers by placing a canopy over part of an adjacent courtyard. The group representing the drivers said yesterday that this area is not appropriate for prayer because it is exposed to the elements, is noisy and is crowded with benches, tables and phone booths.

The cabdrivers said the airport also has not been responsive to their requests for separate sinks in the two bathrooms at the holding facility so that they can wash before prayer.

Jeff Nelligan, a spokesman for the U.S. Department of Transportation, said the inspector general will look into the matter and determine "if there is a safety issue involved or some issue dealing with the financial health of the airport."

Other airports across the country are confronting the issue of religious accommodation as immigrant populations have grown, officials said.

Officials at Denver International Airport, which opened three years ago and has a Christian chapel and an Islamic prayer hall, were approached by Muslim taxi drivers who said the prayer hall was too far for them to get to without losing their place in line, said Chuck Cannon, an airport spokesman. The airport allowed them to use a picnic area, which is acceptable until the weather turns cold, he said.

Because the airport is prohibited from favoring one religion over another, a request from the drivers for a trailer for Muslim prayers was denied, Cannon said. But airport officials told the Muslims they could pray together in a new building for all cabdrivers once construction is completed.

"We said, 'Sure you can,' " Cannon said. "Someone may be playing cards--we're not going to restrict them. But they're welcome to do their daily prayers. There's no problem praying in groups."

CAPTION: Mohammad Chaudhry washes his feet in the bathroom at Reagan National Airport.

CAPTION: Cabdrivers Sharif Amer, left, and Addu Lwahab pray outside National Airport's taxicab holding facility.