Although he doesn't ride often, Arthur Young in some ways is a typical Metro subway rider.

According to a survey of passengers released this week by the transit authority,57.6 per cent of all riders on the city's first subway line are male and 61.7 per cent are under 35 years of age. Young is 25.

Of all riders, 66.5 per cent are college-trained, including graduate study. Young is in that group, an economist with the Bureau of Labor Statistics.

Although not asked his income, he obviously is reasonably affluent. Of Metro riders, 59.2 per cent earn more than $16,000 a year. A surprising 38 per cent earn more than $24,000.

Young was interviewed yesterday on the platform of the Farragut North station by a reporter seeking to confirm the findings of Metro's report, which for the first time provided a profile of who rides Metro and for what reasons. Until now, Metro officials have relied upon educated guesses.

The pattern of Young's and other interviews, both on station platforms and aboard trains, bore out the results of the Metro staff survey, which was conducted by planning and marketing personnel last Sept. 16.

A total of 3,000 questionnaires was distributed roughly one for every six of the 19,175 passengers that day. Responses totaled 1,545, or 52 per cent.

There were few surprises, except possibly for the indication that large numbers of riders rank high on the economic and social ladder -- the apparent result of much midday riding by lawyers and bureaucrats.

The largest proportion of riders, 47.2 per cent, are those who use the subway to travel to and from work,as James Chance was doing when he was interviewed yesterday.

A clerk at the Federal Communications commission and a high school graduate who lives in the District (as 46.8 per cent of all subway riders do). Chance said he takes the subway for its speed and because it is warmer in winter to wait inside a station than at a curbside bus stop.

If he hadn't taken the train. Chance would have ridden a Metrobus. That's the same answer given by 46.2 per cent of all subway riders.

Richard H. Speidel, a 56-year-old lawyer, said he would have taken a taxicab to get from Judiciary Square to his office at 18th and H Streets NW if the subway weren't running. Like many fellow lawyers. Speidel said he has used the trains almost daily since they started running last March 29.

The Metro survey showed that 22.1 per cent of all subway passengers, like Speidel, would have used cabs. Another 20.4 per cent would have driven their own cars, while 2.5 per cent would have ridden as passengers with other motorists. These figures mean that some 8,000 motor vehicle trips on downtown streets were eliminated by the subway.

A scant 1.5 per cent of subway riders, like Ann Ford, might have ridden a bicycle. But in this season, she said she probably would have used a cab while doing her job as a messenger for a major law firm.

Speidel, the lawyer and a resident of Maryland (like 29.3 per cent of those surveyed by Metro) volunteered the things he likes about the subway. They paralleled the advantages cited by riders in Metro's own survey --speed (mentioned by 50.3 per cent of respondents), convenience (17.4 per cent), comfort (7.4 per cent), avoidance of traffic (5.4 per cent) and cost savings (3.9 per cent).

Residents of Virginia account for 15.8 per cent of the current riders, a relatively low figure that is not surprising, since there are no major transfer points between the subway and Virginia buses as there are with buses serving the District and Maryland.

Riders like Young, Speidel and Ford -- those who use the subway traveling to or from job-related business, as distinct from commuting --account for 22.4 per cent of the subway riders.

Personal business accounts for another 12.4 per cent and shipping for 11.2 per cent, although clearly the latter usage was greater during the Christmas season.

Comparatively few riders, like Sharon Barnes, use the subway for getting to and from school (the Metro survey figure is 4.1 per cent.Although there are few schools along the first subway route, a major campus of the Federal City College is near the Judiciary Square station.

The 22-year-old Barnes attends a vocational skill center near the Rhode Island Avenue station.

Barnes found that it is possible to save time by making a roundabout trip that includes a subway ride. It takes an hour, she said, to get by the most direct bus route from her home in the Brightwood section of Northwest Washington to the skill center -- a straight-line distance of two miles. But if she rides downtown and doubles back on the train, it takes only a half hour -- for a seven-mile trip.