Georgetown will move a little closer to Union Station tomorrow when the D.C. Circulator begins rolling through Washington, offering frequent crosstown service on a simple route for $1 a ride. The fleet's 29 buses are designed to offer a more comfortable and convenient transportation option.

The buses will initially operate two routes: an east-west line from Union Station to Georgetown via the Washington Convention Center and K Street and a north-south segment from the Convention Center to the waterfront via Chinatown and the Mall.

The Circulator marks the arrival of a new flavor of bus service that has been successful in such cities as Los Angeles, Miami and Salt Lake City.

"The whole idea is to set it apart from how people thought about the bus in the past -- that it's old and smoky and they don't want to ride it," said Lurae Stuart, senior program manager for bus technology programs at the American Public Transportation Association. "The new philosophy is that you can provide something that is new and snazzy and people will realize that they can ride a bus."

The fare is the cheapest public transportation available downtown -- $1 per trip, compared to $1.25 for Metrobus or $1.35 for Metrorail. Transfers between Circulator buses are free for up to two hours. Architects of the Circulator say it will meet a pressing need: a fast and inexpensive way to cross town.

"Metrorail is a great radial system: It brings people into the city, but it doesn't really bring them around," said William G. Dowd of the National Capital Planning Commission, which came up with the idea in 1997.

The planning commission worked with the District government, two business groups and the Convention Center to launch the Circulator. To buy the buses and fare machines, they used $12.5 million from a 1960s legal settlement earmarked for city bus service.

The buses, with red and black exteriors that include a simplified system map, have a certain curb appeal. Before service began, curious passersby asked if they could board an idling Circulator. "I like it," Miguel Rodriguez, 21, of Southeast Washington said as he looked around inside.

The buses will run every five to seven minutes and have three doors for fast loading. On two downtown streets, Seventh and Ninth streets NW, the Circulator will travel in a designated lane to bypass traffic, said Dan Tangherlini, D.C. director of transportation.

Compare that to the Metrobus system, which maintains complex schedules, uses aging buses with a single door for boarding and has many lengthy, complicated routes that bog down in traffic.

"A lot of tourists may want to take a bus but have no idea if the X2 goes to where they want to go," said Joe Sternlieb, a deputy executive director of the Downtown Business Improvement District.

Tourists are just one segment of the potential ridership, Sternlieb said. "We want tourists, we want office workers, kitchen workers, residents," he said. "The target is everybody. We want people to think of taking the Circulator the way they take Metro."

The Circulator could help take the pressure off an overburdened subway, said Tangherlini, who represents the District on Metro's board of directors. "We are running out of capacity on the rail system," he said. "Are there people taking a one- or two-stop train ride who could be on the bus instead?"

Projected daily ridership is 4,478 on the north-south line and 9,170 on the east-west line by 2008. The District, federal government and private sector are sharing the $6 million in operating subsidies for the next fiscal year.

First Transit, a private transportation company that runs the DASH system in Alexandria and the shuttle buses at Baltimore-Washington International Airport, will operate the Circulator.

Tangherlini said the District decided against having Metro provide the new service because First Transit could do the job for less -- $57 for one hour of service per bus compared to $76 charged by Metro, he said. Metro will manage the service for $519,000 a year.

The Circulator buses, manufactured in Belgium by VanHool, are 40 feet long. They are the same length as a standard Metrobus, but similarities end there.

The buses are low-floor throughout, so passengers step from the curb the way they would board a subway train. The black, red and gray interior has fewer seats than a Metrobus and more room for standees. In the center is a large area with room for two wheelchairs. The Circulator buses have tall windows, including a large rear window, giving the bus an airy feeling and enabling passengers to survey the passing scenes.

Tickets can be purchased ahead of time at vending machines at 13 of the 51 stops on the routes. Checkers will randomly ask for tickets on buses; riders without one can face up to $60 in fines, Sternlieb said. The Circulator will also accept cash, SmarTrip cards and Metro transfers. Rides will be free for the first week.

If the service is successful, the District and its partners plan additional routes.

Georgetown businesses started a similarly innovative but much smaller bus service in 2002 that shuttles between the Dupont Circle, Foggy Bottom and Rosslyn Metro stations and Georgetown. It has proved highly popular.

Not everyone is enthusiastic about the Circulator. Tom Mack, owner and general manager of Tourmobile Inc., said the Circulator is a threat to his buses. "I don't believe federal monies should be used in similar operations in competition with private industry," said Mack, whose company has held exclusive rights to provide the sightseeing transportation on the Mall under agreements with the National Park Service dating to 1969. The average adult fare is $20 for the day.

But Tangherlini said the Circulator offers a service that differs from Tourmobile's. "This is easy and cheap and comfortable and designed to get people where they need to go," he said.

The D.C. Circulator fleet is made up of 29 buses.Circulator buses, which had practice runs to Union Station on July 4, are low so that riders don't have to take a high step up. They have fewer seats than a Metrobus, but more room for standees, and a wheelchair area.