Many late-night and weekend bus riders recently have waited at stops in Washington and Northern Virginia for buses that never came because of a Metro management crackdown on driver tardiness.

The reduction in service has been particularly noticeable on Sundays and has had its heaviest impact in Washington on routes serving Anacostia, Benning Road and 14th Street NW. Bus routes connecting National Airport with downtown Washington and other parts of Northern Virginia have also been hard hit on Sunday.

"There is no question there has been a disproportionate loss of service on nights and weekends," said Thomas Black, Metro's new director of bus services. Black said there had been a misunderstanding on the part of some supervisors on how to apply new rules designed to reduce Metro's chronic tardiness and absentee problems.Another new rule to correct the misunderstanding was dispatched to Metro's eight bus garages yesterday.

Our exasperated bus rider, who asked that his name not be used, called The Washington Post on successive Mondays to report that he was unable to get into the city from the airport after 10 p.m. Sunday, when the subway closes at 6 p.m. Only two buses are scheduled into Washington from the airport between 10 p.m. and midnight; neither ran either Sunday, according to official Metro records.

"There were four of us standing there," the man said the first time. "We waited for more than an hour. We called Metro, nothing happened. We finally shared a cab."

On a percentage basis, the number of trips missed does not appear to be significant. Last Sunday, for example, Metro eliminated 44 of 6,804 scheduled trips, or only six-tenths of 1 percent of scheduled service. However, all but five trips eliminated came after 4 p.m., when scarce service get scarcer, and the eliminations heavily affected trips in the 14th Street NW and Anacostia sections, where buses are used extensively. Similar examples could be found in a random check of records throughout the system.

Furthermore, the problem developed suddenly. On the first three Sundays of January, records show, Metro missed a total of four trips. On the first three Sundays of February, Metro missed 140 trips.

The story begins, as all Metro service stories do, with the takeover by Metro of four privately owned bus companies in January 1973. At that time, bus service had deteriorated badly throughout the metropolitan area and the financially strapped private companies avoided bankruptcy until the takeover by eliminating many bus trips.

When the takeover came, the politicians of the Washington area promised to correct the loss of service, and the word went out to the managers: Run the buses, no matter what.

For the most part, they did. However, in recent months, Metro has imported new bus management. (Thomas Black) and the Metro board has been placing increasing emphasis on controling the budget.

One very expensive item in the budget is the 492 bus drivers (of 2,781) who have no specific daily assignment. Designated as 'extras,' they are used as relief drivers for operators on vacation or sick leave. If there is no work, they are paid anyway.

Many extras were needed, Black discovered, because many regulars showed up late for work and the extras were dispatched to maintain the schedule. If a regular driver came to work late and found his trip had already been taken by an extra, it was unofficial Metro policy to give the regular driver work later in the day. "There was no real penalty for being late," Black said.

No more. Effective Feb. 1, Metro enforced a rule that no driver who was late could be given work that day. The intention was to reduce tardiness -- and ultimately the number of extras. It has worked.In the second full week of January, 178 drivers reported late. In the second full week of February, the number was 121.

For taxpayers not waiting endlessly at the bus stop, that is good news. Metro saved about $10,000 in Driver salaries the first week in February, Black said. "We may have done even better the second week," he said, "but that was before I knew what was happening on weekends."

Accompanying the new rule were guidelines on "selective service cuts" to be used to garage superintendents if they had to eliminate a few trips to keep the troops in line. The guidelines say, among other things, that the trip must be operated if it is the first or last trip of the day on that route or if there are more than 30 minutes between buses on that route. In other words, most weekend and last night trips should be run, no matter what.

The guidelines, according to Leroy Bailey, general bus superintendent, were transmitted orally. Some garages in Metro's system got the word and some did not. Most of the missed trips came from three garages. Four Mile Run in Arlington, and South eastern and Bladensburg in Washington.

"That's lesson for me," Black said, "We'll put things in writing."

A footnote the policy has infuriated Local 689 of the Amalgamated Transit Union, which represents the drivers. "They didn't give the drivers any warning," said Jack Thomas, financial secretary of the local. "They just told the superintendents. This is right out of George Orwell."