Ridership on Metro trains and buses increased 15 percent in the 1979 fiscal year to a total of 154 million trips, the largest rise in a single year since Metro took over the area's private bus companies in 1973, the transit authority reported yesterday.

However, despite the opening and expansion of the multibillion dollar subway system, the total number of passengers using both trains and buses still has not equaled the 160 million trips recorded in 1967 by the then-all-bus system.

Patronage began plummeting the following year, which was marked by urban riots and the first of a series of frequent bus fare increases. By the time Metro took over in 1973, annual patronage had fallen to 117 million.

The all-time record was set in 1946, the year after World War II ended, when Washington's streetcar and bus systems hauled 410 million people. That figure did not include suburban bus travel.

Richard S. Page, Metro general manager, attributed last year's increase to the expansion of the rail system (which began running in 1976), improved feeder bus service to subway stations and, to a lesser extent, the rising cost and scarcity of gasoline in recent months.

"This is more evidence of a rebirth of public transit," Page told reporters after yesterday's Metro board meeting. Noting that the bus system shared in last year's growth, Page said, "The image of the bus used to be unfavorable - it was only for poor people. Now you see people with pinstripes riding."

In Metro's 1979 fiscal year, which ended June 30, train riding grew to 59 million trips from 37 million the previous year. Bus riding grew to 120 million trips from the previous year's 113 million. (The two do not add up to the systemwide total of 154 million, the report noted, because people who transfer from one vehicle to another on a single trip are counted only once.)

Translated into daily figures, an average of 227,572 people rode the subway each weekday while, by the beginning of June, a total of 469,338 rode the buses.

This summer's gasoline shortage spent the subway ridership figures soaring. By the week that ended June 29, an average of 293,037 people rode the trains each weekday. On two days, June 15 and 19, train riding topped 300,000 setting a system record.

By last week, daily train patronage had slipped to an average of 268,037 as some passengers apparently returned to their cars.

By 1990, Metro is forecasting that 885,781 passengers will travel each weekday on the 101-mile rail system it is planning. If last year's growth rate continues, Page said, it will far exceed that goal.

Yesterday's report showed what commuters bucking afternoon rush-hour crowds must already know: that the Farragut West station on the Blue Line is the busiest one among the 33 stations now in use.An average of 26,161 passengers boarded the trains there each weekday in June.

Its "twin" station on the Red Line, Farragut North, was used by about half as many boarding riders, 14,906. Many Red Line passengers use the Dupont Circle station that serves the same neighborhood.

The least patronized station on the system was, for apparent reasons, Arlington Cemetery, where only 670 passengers boarded each day. The next lowest patronage was reported at the Cheverly station, on the Blue Orange Line in Price George's County, with 1,566.

After Farragut West, the five next busiest stations, in order, were: Rosslyn, 21,573 Pentagon, 21,096 Silver Spring, 17,385 Metro Center, 16,596, and Dupont Circle, 15,653.

The statistics showed that the six stations on the Virginia (National Airport) end of the existing Blue Line produced 62,142 boarding passengers each weekday, while the three stations on the Maryland (New Carrollton) end produced only 11,418. CAPTION: Picture, The number of subway passengers, like these at the Farragut North station, rose from 37 million to 59 million during the last fiscal year. By Ken Feil - The Washington Post