By any measure, Metro's labor contract has given its bus drivers and train operators better protection against inflation than the contracts or salary schedules for other area public employes, a Washington Post survey shows.

The Metro driver's advantage is particularly noticeable in a single year that features high inflation, such as this one. Over a period of years, however, the advantage is not as great as many local politicians claim when they are railing against the Metro contract.

The hourly pay rate for Metro bus drivers has increased at a rate in excess of the rate of inflation since Metro's takeover of four private bus companies in 1973. That is because transit workers received a few small salary increases in addition to quarterly cost-of-living increases. Since 1975, however, they have received only cost-of-living increases.

At the same time, according to The Post survey, salary schedules for four public employe categories have risen at a smaller percentage rate than both the cost of living and the Metro salary schedule.

Here are the percentage increases in salary schedules from July 1, 1973, to March 2, 1980, when Metro drivers got their latest raise: (TABLE) Consumer Price Index(COLUMN)74.8 percent Metrobus Driver(COLUMN)82.9 percent D.C. school teacher(COLUMN)52.2 percent Arlington fireman(COLUMN)41.4 percent Montgomery policeman(COLUMN)40.5 percent (END TABLE)

However, salary schedules do not tell the story of what happens to real people. Most public employes receive substantial "step" increases each year in addition to across-the-board percentage increases. Metro drivers, however, receive no step increases after their third year.

Therefore, a real person who went to work on July 1, 1973, and who followed a normal career pattern would have the following percentage increases in salary to show for his efforts: (TABLE) Metrobus driver(COLUMN)103.3 percent D.C. school teacher(COLUMN)90.1 percent Montgomery County policeman(COLUMN)90 percent Arlington County fireman(COLUMN)89.5 percent (END TABLE)

There is one other major area of difference, and this is where Metro drivers win the salary comparison hands down. An Arlington fireman or a D.C. teacher usually has to wait one year between salary increases, the amounts of which are known in advance. Therefore, local governments know precisely what their salary costs will be in a given year.

In Metro's case, the adjustment is unpredictable and must be made four times a year. If Metro had given its drivers just one salary increase in the current fiscal year, at the first of the year, and salaries had remained constant throughout the year, Metro would have saved $4.2 million in salaries. c

Even if the Metro drivers' salaries were raised by the full percentage at the beginning of the next fiscal year, that $4.2 million would still have been saved.

The individual bus driver, because of the quarterly adjustments, is $682.93 better off this year than he would have been if he had to wait one year for a full cost-of-living increase instead of receiving quarterly adjustments.