Unscheduled absenteeism among transit workers is costing Metro about $16 million a year in overtime and salaries for employes it otherwise would not have to hire, according to a Metro study released yesterday.

Furthermore, the study said, 80 percent of the unscheduled days off at Metro are taken by only one-fifth of its 5,000 bus drivers, train operators, station attendants and mechanics. A hard-core one percent of employes is responsible for almost 10 percent of the problem, the study says.

That means that four of five operating employes "do not abuse sick leave, workers' compensation or, in general, have significant absenteeism problems," a Metro committee said.

The committee's report is the result of a months-long study into a problem that plagues both private industry and public employment. The study was ordered because of the Metro board's growing concern about increasing absenteeism and its high cost to the taxpayers who subsidize Metro's budget.

Metro's record fiscal 1981 budget of $275 million will require federal, state and local subsidies of about $111 million.

The committee figured that the total cost of all absences to Metro in fiscal 1981 would be $32 million, including $9 million for workers' compensation and $1.7 million in unscheduled overtime. The remaining $21 million includes scheduled paid vacations plus unscheduled absences.

Subway station attendants and bus drivers were the two categories of employes with the highest absentee rate. Station attendants -- many of whom have been medically disqualified from working as bus drivers -- missed an average of 26.81 workdays per year during the period surveyed.

Bus drivers missed an average of 16.85 workdays per year. Mechanics for both the bus and subway systems trailed.

The report was produced by a committee that included Mark Weiss from the Metro staff, the chairman, and members from Maryland, Virginia and the District of Columbia.

The committee recommended a number of procedures to deal with the problem, but stressed in its report that most employes were doing their jobs and should be rewarded for that. The committee said that employe unhappiness about working conditions expressed itself in absenteeism.

One area of discontent the committee found in a series of interviews was that bus drivers and mechanics are prohibited from taking one-day vacations occasionally -- something that many other Metro employes can do.

"We should reward people with excellent attendance records by giving them what they can't get now -- an occasional day off," Weiss said.

In addition to the single-day-off problem, Weiss said, the committee found discontent because:

Employes, particularly drivers and station attendants, felt they were automatically presumed guilty by their supervisors whenever a patron complained.

Employes felt they were not consulted on matters that affect them or their jobs.

Employes felt they were not recognized for good work.

Other factors cited included a feeling that top management is indifferent to employe problems and that the local press gives a one-sided, management-oriented view of labor problems.

Absentee rates were found to be higher at the Southeastern Bus Garage, Half and M streets, SE, than elsewhere. The committee suggested that that could be because the routes served by that garage -- that traverse Anacostia and other Southeast neighborhoods -- are unpopular with the drivers. Further, the garage is simply not a pleasant place to work because it is old and some of the outdoor bus parking areas are muddy, the committee said.

Weiss said he was particularly concerned in talking with bus mechanics to find that there is an "absence of peer pressure" to go to work.

Metro General Manager Richard S. Page praised the report and promised it will be followed up. He said he wants to find a response to the problem that would increase the number of "good, repsponsible, conscientious" employes, not decrease them.