More people rode Metrorail in the past year than in any year since the subway opened in 1976, at one point breaking the record for single-day ridership.

Although rail ridership grew by 3 percent overall in the fiscal year that ended June 30, it shot up by 10 percent on weekends, suggesting the return of tourists and conventioneers -- a category of riders that nearly disappeared after the terrorist attacks three years ago, Metro budget analysts said yesterday. Average weekday ridership was 652,578 on the trains and 502,971 on the buses.

Evening ridership grew 3.5 percent and the expansion of late-night rail service on weekends, from 2 a.m. to 3 a.m., proved more popular than expected. The number of night-owl passengers was 16 percent higher than Metro analysts had predicted.

The subway set a record for the most passengers in a single day on June 9, the first day of the state funeral for former president Ronald Reagan, when it carried 850,636 riders.

Metro Chief Executive Richard A. White pointed to several factors driving rail ridership: an increase in the local employment rate, the return of tourists, the opening of the new Convention Center, as well as several special events in which the public was encouraged to take transit, such as the Reagan funeral and the dedication of the National World War II Memorial.

While trains were packed, bus ridership fell slightly. Metro officials said there were 1.3 percent fewer bus riders than in the previous year. But White cautioned that the statistic may not be accurate because it's based on data from old bus fareboxes with counting mechanisms that were notoriously unreliable.

"We've had huge trouble getting accurate ridership information from the buses," he said. New fareboxes that have been installed on all Metrobuses are expected to deliver better data, he said.

MetroAccess, the curb-to-curb van service for the disabled and elderly, logged more miles. Average MetroAccess ridership increased 14 percent on weekdays and 16 percent on weekends, compared with the previous year.

Unexpected revenue from joint development projects near stations and tunnel space leased to fiber optics companies yielded a modest surplus of about $1.8 million, which transit managers said they will put in a reserve account for operating costs.

It is too early to tell whether fare increases that took effect June 27 will have any effect on ridership in this fiscal year, Chief Financial Officer Peter Benjamin told Metro board members yesterday. Because summer vacations are over, and children have returned to school and their parents to work, Metro officials say, any loss of rail riders should become apparent this month.

Despite record-smashing rail ridership -- and record revenue from fares -- Metro officials say the agency still faces significant financial hurdles and is running out of ways to address them. They expect a $40 million shortfall in next year's operating budget and a $30 million deficit the year after that.

Budget analysts blame the same factors for increasing expenses each year -- health insurance for the agency's 10,000 workers, pension costs and rising diesel fuel prices.

One problem Metro faces as it tries to reduce health care costs is union-negotiated contracts that require the transit system to pay 90 percent of health care costs while employees pay 10 percent. In addition, the largest union, Local 689 of the Amalgamated Transit Union, has the most expensive health care coverage, from Blue Cross and Blue Shield. The union represents about 7,600 Metro employees, including train operators, bus drivers and station managers.

While Metro routinely seeks competitive bids for health insurance and changes carriers for its nonunionized employees, it has never deviated from Blue Cross and Blue Shield for most of its unionized workers. To do so would require union approval, said Bill Scott, Metro's assistant general manager for workforce development. "Their members have a comfort level with Blue Cross and Blue Shield," he said.

Scott said the transit system is trying to negotiate a new contract with its unions that would shift the burden of health care costs so Metro pays 85 percent of coverage and employees pay 15 percent.

Metro's operating costs are paid by a combination of passenger fares and parking fees, subsidies from local governments served by the rail and bus system, and revenue from advertising and other sources. Fares and fees were stable for eight years, until the Metro board raised them last year and again in June.