Starting Monday, figuring out how to get from point A to point B using mass transit will get a little easier.

Metro will become one of the first transit agencies in the country to offer interactive trip planning on its Web page. Computer users who click onto will be able to type in their address and destination and get door-to-door directions, which include walking directions to bus or train stations, trip time, arrival and departure times and exact fares.

"This is breaking the code on how to navigate the regional transportation system," said Fairfax County Board of Supervisors Chairman Katherine K. Hanley, Fairfax's representative and chairman of the board of directors for Metro. "In a region where we are as wired as this, this is a really important step."

The Ride Guide cost Metro about $200,000 and blends the transit agency's geographic and transit databases. It covers all 11 jurisdictions in which Metro operates.

Metro officials will work with the tourism and convention industry to publicize the availability of the information system for visitors to the region.

Metro riders still can get information by telephone at 202-637-7000. The telephone information number is one of the most heavily used in the region, getting 3 million calls a year. But it is available only during regular business hours.

The directions system is the latest in a series of high-tech travel aids introduced by Metro this year. Last spring, Metro began offering riders the option of buying Farecards and passes with credit cards over the Internet.

Other innovations included the introduction of "smart cards," which allow riders to pay for rail travel and for parking in Metro lots. The blue and green SmarTrip cards are embedded with tiny computer chips that store fare value.

Many transit systems across the country are trying to take advantage of computer innovations to attract new riders for their systems and improve service for current customers.