A LOOK AHEAD * Mayor Richard Riordan will soon become chairman of the Metropolitan Transportation Authority. From depoliticizing decisions to scrutinizing the agency’s budget, his sweeping plan could herald a ... : Change of Direction for the MTA

When Los Angeles Mayor Richard Riordan assumes the chairmanship of the Metropolitan Transportation Authority’s board Tuesday, he will bring with him a concise, carefully conceived agenda.

But despite its brevity, it is a plan of sweeping scope and, for the MTA, revolutionary implication. Riordan’s priorities include:

* Quickly finding a strong, tough-minded chief executive to run the agency.

* Depoliticizing transit decisions by working with the state Legislature to rewrite the MTA’s charter, reducing the board’s size and replacing the elected officials on it with non-elected appointees.

* Conducting a top-to-bottom review of the agency’s legendary wishful budget.

* Halting expensive studies of rail lines that won’t be built for decades, if ever, and looking instead for ways to bring faster, cheaper mass transit to all the county’s regions by refocusing on buses.

Riordan, said a source familiar with his thinking on the matter, is approaching his new job like the purchaser of a valuable but problem-filled property: He knows “it’s not a fixer-upper. It’s a tear-down.”

In fact, when the mayor was reminded during an MTA meeting last week that he would be taking over as chairman Tuesday, he pointed his index finger to his head, cocked his thumb like the hammer of a mock gun and fired.

Still, Riordan insisted during an interview at his City Hall office last week, “I love challenges. I really do.”

Riordan could face his first one as chairman even before he steps out of bed Tuesday. Contracts for 6,300 bus and train operators, mechanics and clerks expire at midnight tonight. If no agreement is reached, a strike could occur as early as Tuesday. Negotiations continued late Sunday, and some progress was reported.

Riordan, previously elected by board members to serve as vice chairman, automatically takes over when MTA Chairman Larry Zarian’s two-year term expires.

Although serving as official spokesman for the unpopular MTA can be a political headache, Riordan aides see it as an opportunity for the mayor to create a legacy for himself, much as President Dwight D. Eisenhower did with the interstate highway system and former Gov. Edmund G. “Pat” Brown Sr. did with the state water project.

Some MTA board members worry that Riordan will go beyond his official duties. Even before becoming chairman, Riordan has dispatched his City Hall budget experts to begin reviewing the $2.8-billion MTA budget.

“Dick is kind of a one-man show,” said MTA board member James Cragin, a Gardena city councilman.

Other board members complain that Riordan has gone off on his own without consulting the rest of the board, such as meeting with union leaders in the midst of labor negotiations and privately interviewing CEO candidates--including the current favorite, Shirley DeLibero, a black woman who heads the New Jersey transit system.

Riordan’s reply is simple: “The public is going to hold me accountable for what I get done.”

As MTA chairman, Riordan also will be held accountable for the nation’s most crowded bus system and the trouble-plagued $6.1-billion subway project. The agency still must determine exactly how it will meet its court-ordered deadlines to improve bus service. Concurrently it is struggling to mend relations with Sacramento and Washington, where officials have grown weary of cost overruns and delays on the subway project, which state and federal taxpayers are helping fund.

The agency also is preparing to embark on a potentially troublesome phase of subway construction--using explosives under the Hollywood Hills and tunneling for an Eastside route that will run under more homes and businesses and through trickier soil than anywhere else in the system.

Eric Mann, leader of the Bus Riders Union, a plaintiff in the civil rights lawsuit that produced the federal consent decree mandating bus improvements, said he wants to see if the mayor, once he becomes chairman, delivers on his promise of improved bus service.

“He has made the highest rhetorical commitment to us,” Mann said. “But we don’t have one more bus from Richard Riordan than our worst opponent on the board.”

In the interview, the mayor repeated his dedication to a dramatically improved bus system. Aides describe him as furious over the MTA staff’s slow pace in reforming the bus system. However, some union leaders and environmentalists doubtless will oppose some of the changes Riordan and his aides are considering--contracting out more lines to private bus companies and slowing down the purchase of cleaner-burning buses that run on alternative fuels in favor of cheaper buses powered by diesel that meet air pollution standards.

The mayor speaks enthusiastically about Curitiba, Brazil, where 300-passenger triple-length buses have been put into service on busways at a fraction of the cost of rail. A Riordan aide recently toured the city, and the mayor said he plans to send a slide show of her visit to neighborhood groups around Los Angeles.

The MTA, at Riordan’s urging, is already studying whether an above-ground rail line or other alternatives can be built more quickly and more cheaply than a $250-million-per-mile subway across the San Fernando Valley. Funding has yet to be assured, and construction of the 15-mile line is not scheduled to start until at least 2007 and probably will take six years. The mayor also would like to see some sort of plan that would alleviate congestion along the San Diego Freeway.

Riordan also has questioned whether the MTA can afford a subway extension to Mid-City and eventually to the Westside. The cost of the 2.3-mile extension from Wilshire Boulevard and Western Avenue to Pico and San Vicente boulevards has soared from $490 million to $682 million at the same time that the MTA has received less federal funds for the subway project than expected. The MTA board will face a critical decision this fall on how to proceed on the Mid-City project, which is not expected to be completed before 2008.

Although Riordan said he has not made up his mind about what kind of mass transit project ultimately should be built in the Valley and Mid-City, he said he believes that if the MTA can stretch its dollars, it can bring transit sooner to more regions.

Riordan already has found a key ally in Assembly Transportation Committee Chairman Kevin Murray (D-Los Angeles), who is pushing legislation to provide a state loan for designing express busways on Crenshaw and Exposition boulevards.

Murray said express busways could encounter political resistance. “How do you tell people that in one place they get a billion-dollar subway, and we get a bus?” said Murray, who also toured Curitiba.

The lawmaker said he is not giving up on rail lines along Crenshaw and Exposition, but wants some kind of mass transit in his district now. “By making our proposal more modest, we get something now,” he said.

One MTA official, however, said that a busway on the Exposition right of way between Santa Monica and USC would run into a “buzz saw” of opposition from Westside neighborhoods concerned about the noise. But Murray said that a busway would be less disruptive and less noisy than a train.

“There are so many innovative things that can be done,” said Riordan, “such as having smart shuttles roaming neighborhoods and connecting people to express buses, having dedicated bus lanes. . . . If we come up with economical ways, we can get things done very quickly.”

In dispatching his city budget experts to the MTA, Riordan complained that the MTA is spending money studying unfunded rail lines that won’t be built for years, if ever. Though the mayor declined to name the studies, MTA officials confirmed they are spending $1.5 million studying a rail line in the Crenshaw district, and have spent another $1 million exploring ground conditions for a western extension of the yet-to-be built Mid-City extension. Planners defend the studies as necessary, so they have the projects ready to go when funding becomes available.

Riordan also complained that the MTA’s projections of sales tax revenues--the agency collects one cent of every dollar spent on taxable goods in Los Angeles County--are twice as high as the city government’s estimates.

Riordan already is spending a lot of time trying to mend the agency’s relations with Sacramento and Washington. As chairman, he plans to do even more. In other areas, he is expected to take a lower public profile than past MTA chairmen, delegating matters to the agency’s CEO and his 27-year-old transit advisor, Jaime de la Vega, who is highly regarded among other transit officials.

But Riordan does plan to continue pushing for the state legislation that would “take the politics out of the MTA” and replace elected officials with appointees--a move critics say would allow the mayor to remain a behind-the-scenes power, while escaping blame for unpopular decisions.

Riordan said he “performs better” under difficult circumstances. “I’m always an optimist,” he said.