The Washington Metropolitan Area Transit Authority - Metro - is in the throes of a financial and political struggle that has the potential to destroy it and dramatically alter public transportation for area residents.

That gloomy assessment comes after months of interviews with local politicians, federal officials and outside observers familiar with Metro.

The wildcat transit strike that stopped Metro for six days ending last Thursday had its roots at least partly in that struggle, which is placing enormous political pressure on Metro's management to control costs any way possible.

If Metro's underlying financial problems are not resolved, the consequences will be more widespread than just the failure of a political organization. The shape of the metro-politan area's transportation network in the years to come is quite literally at stake.

The Metro subway can either be a weekday commuter railroad, as it is today, or it can be the full-service, seven-day-a-week high-quality transit system that was intended.

Metrobus can either be a well-integrated, carefully coordinated complement to the subway that also provides good neighborhod service, or it can be carved into several small, separately operated, poorly integrated fiefdoms. Montgomery County's popular Ride-On minibus service is feared by some Metro insiders and union leaders as the beginning of the end for Metrobus.

The District of Columbia and its close-in urbanized suburbs from Silver Spring to Alexandria will either become more buried in automobiles than they are today, or they will hold their own with the help of a full-service Metro system.

The pressure to control costs comes from Metro's increasing demands on local budgets and property taxes. Many persons interviewed say the Metro coalition of local governments is endangered by these demands, especially when combined with such other forces as:

The uneasy feeling of local politicians that the federal government is abandoning them with regard to Metro construction. For the first time in years, the federal budget for fiscal 1979 contains no money for Metro construction.

The lack of assured, regular funds from nonproperty tax sources for Metro deficits.

Metro's unresponsive organizational structure, which emphasizes the authority and needs of individual jurisdictions rather than broader, regional needs.

Everybody agrees that the cost of operating a full-service subway fed by a well-integrated bus network and of less congested urban-area streets is going to be very high. Nobody really knows how high.

Furthermore, the subway as an institution is beyond the point of no return. There are going to be large local and federal expenses regardless of the kind and quality of transit service that is eventually chosen. The question is whether these costs are going to be managed intelligently or haphazardly.

The strike last week could not have come at a worse time because Metro's board members and planning staff were already in enough trouble trying to meet an Aug. 31 deadline, when they must give the federal Department of Transportation their proposals for financing the construction and operating costs of Metro in the years to come. Such a plan must have federal approval before Metro receives more federal aid.

One of Metro's allies in that presentation was the broad-based public support for the transit system that had been re-established before the strike after years of uncertainty. Transit ridership had been increasing steadily, due largely to the popularity of the expanding subway, and was exceeding half a million trips per weekday. It is too early to tell what the strike will do to ridership, but historically strikes permanently cost transit systems some riders.

The long-range financial problems of Metro, however, are of more consequence than those caused by one strike. Here are the financial facts:

It will cost $100 million more to operate the subway and buses this fiscal year than will be collected in fares. Most of the difference will be made up by local taxpayers.

The combined bus and subway dificit could expand to $300 million or $500 million or even more by 1990, depending on many variables including the number of riders, the fares they pay and the addition or subtraction of constraints on automobile travel.

Metro owes a $1 billion debt on bonds it sold to raise construction money. The interest on the bonds and the principal were supposed to be repaid from subway fares. That optimistic assumption was false, and Metro does not have the money to pay the debt.

It will cost at least $3.5 billion more to build all of the planned 100-mile subway than was predicted a decade ago.

These facts mean that local taxpayers will be asked to provide public transit with hundreds of millions of dollars, much of it from the property tax. The request is coming when the sons and daughters of Proposition 13 are abroad in the land and when less, not more, seems to be the message taxpayers are sending about public services.

"We are putting a significant federal investment in the ground," said one federal official who has been busy holding Metro's feet to the fire on questions of financial responsibility.

"Even if we find all the money needed to complete this system, there is a significant question in our minds as to whether the local governments will be able to operate the system.If they can't our investment isn't worth much."

A central problem in resolving these issues is that Metro "is not well constituted and empowered to make any of the fundamental decisions on which Metrorail and Metrobus operations depend," according to Wayne Anderson, executive director of the Advisory Commission on Intergovernmental Relations. Anderson is a respected fiscal analyst who once knew Metro first-hand as Alexandria's city manager. He made that statement at a recent conference on Metro problems called by the Washington Center for Metropolitan Studies.

Theodore C. Lutz, Metro's general manager, agreed with Anderson. The financial pressures on local area governments to support bus and rail operations, Lutz said, have made it "almost impossible" for Metro board members to vote regionally instead of parochially.

There are two reasons:

Metro does not have the authority to tax and its transit services do not earn enough income to pay operating costs. That means Metro must go begging to local governments to make up the difference. Metro is the "only governmental body I know that operates solely on voluntary contributions," in Lutz's words. Therefore, if any of Metro's partners gets angry about the bus and subway bills, there is literally no way to force payment.

Everybody has a veto. Under the compact that established Metro as a partnership of the District of Columbia, Maryland and Virginia, each of those three bodies has two votes on the Metro board for a total of six. For a motion to pass, it must have four votes, including at least one vote from each of the three jurisdictions.

Thus, if Maryland and Virginia decide that a 10-cent fare increase is a good thing and cast four votes in favor, the District of Columbia could veto the decision with its two votes.

The arrangement guarantees that no two partners can gang up on the third, but it also means that even seemingly simple decisions can take weeks or months while the necessary set of political compromises is constructed to make sure that nobody walks away from the table.

So far, every financial crisis has been resolved.

However, the thing that makes Metro so incomprehensible even to the casual observer - its mind-bogging fare schedule - is the direct result of the kind of compromise that springs from a body with inadequate detachment from parochial interests to make intelligent regional decisions.

The District of Columbia government believes in low fares and big subsidies; Northern Virginia governments generally believe in high fares and low subsidies; Maryland governments fall somewhere in between.

Thus, a typical rush-hour bus-only trip in the District of Columbia costs the rider 50 cents; in Virginia it costs the rider 90 cents and in Maryland it costs the rider 70 cents.

Because the costs and revenues of each bus line are assigned to one local government or another, situations develop that appear insane to the rider:

A half-full express bus from Montgomery County will go whizzing by commuters standing in a snowstorm on Connecticut Avenue in Washington, unable to get on D.C. buses because they are jammed.

A bus that starts in Fairfax County runs through Arlington with its doors closed.

"We're almost down to the point where we're tagging people with the names of the places they live so we can charge (the cost of the ride) back to the right jurisdiction," Fairfax County Supervisor Marie Travesky recently told a Virginia legislative committee.

The subway presents more of a challenge because it must be operated regionally, with a fare schedule that is the same for everyone, no matter where they get on or where they get off.

Thus, after months of agonizing meetings, the Metro board arrived at a fare schedule that includes these anomalies:

A short rush-hour trip costs 40 cents, or 10 cents less than a non-rush-hour trip, regardless of distance.

Rush-hour trips across the Potomac River cost a minimum of 45 cents, while longer rush-hour trips within both Virginia and D.C. cost only 40 cents.

The fare is the same for each trip made between given points at a given hour, but the logic behind it defies explanation.

The latest fare package, which went into effect July 2 and raised fares for most suburbanites and some longhaul D.C. subway riders, took the Metro board more than six months to implement, counting all the committee meetings, private phone calls, public hearings and final votes that were needed.

Lutz and his staff produced series after series of financial projections on what each fare schedule would mean in terms of riders and revenue.

D.C. held out for low fares, which if is under considerable political pressure to provide. Arlington asked for high fares, in keeping with its belief that the user should pay the cost. Fairfax County insisted on high fares, then discovered that the last fare increase had driven county residents from the bus system. So Fairfax switched its support to a hold-the-line position. Montgomery County insisted that the cost of the subway ride from Silver Spring to Metro. Center could increase by no more than a nickel - exactly 7 per cent, or the amount of increase the Metro budget anticipated.

"This is no way to run a railroad," one board member said in the midst of the debate. Nobody laughed.