The financially troubled state of Pennsylvania had to shut down its entire highway construction program more than a year ago because it was out of money. Six thousand highway department employees have been laid off in recent years for lack of funds. About 30 employes have been indicted in the last two years on charges of taking kickbacksk or running shakedowns in connection with various highway programs.

But the biggest problem in Pennsylvania is much less spectacular.It is maintenance.

Pennsylvania "is threatened with the very real possibility of losing a large part of its total highwayinvestment" because of deterioration and lack of maintenance, according to a state transportation advisory committee.

Pennsylvania is not alone, although its difficulties are regarded as the most severe of any state. The problem of increasing costs in highway maintenance and construction accompanied by a relative decline in tax revenue has imperiled the well-being of highways nationwide.

Just as an example, sections of Pennsylvania's Interstate 80, a main east-west route between New York and Chicago, are a mass of potholes, badly deteriorated shoulders, unsafe guardrails and other less obvious problems.

Much of the paving is less than 15 years old. Many of the problems could have been postponed or even prevented with an adequate maintenance program, according to Federal High way Administration officials who recently completed a mile-by-mile survey of Interstate 80. Since maintenance has been rare, however, much of the road will have to be reconstructed.

Federal aid is available for "resurfacing, restoration and rehabilitation" of interstate highways, but not for such road-saving routine maintenance as sealing cracks and filling potholes. In other words, the highway has to be falling apart before federal aid become available.

Regardless of who pays, however, the cost of fixing the interstates may exceed the money available.

The price of roadbuilding rose to 140 percent between 1962 and 1976. The gasoline tax revenues that make up more than half the federal highway budget and pay for most state-level work fell during the Arab oil embargo of 1973, and have since been growing at a slower pace than costs.

Gasoline taxes are traditionally assessed on a per-gallon basis. Therefore gasoline tax revenues do not respond to inflation, but only to an increase in the amount of gasoline sold.

With resources thus limited, it becomes "a continual fight internally" to determine where money will be spent, according to David C. Sims, Pennsylvania's deputy secretary for highway administration. "Local taxpayers want the maintenance money spent on roads they use rather than on roads other people use when travelling through," Sims said. Maintenance is a county responsibility in Pennsylvania, and the county maintenance supervisor is a political appointee.

Sims is one of the growing minority of state highway officials who want to see federal aid for interstate maintenance flow from Washington at the same rate as construction and reconstruction money: nine federal dollars for every local dollar.

"To let the interstate system go to pieces because some states can't maintain it is ridiculous," said Sims. "When you think of the tremendous amount of money that is put into defense, it just doesn't seem right."

Isn't Sims really just looking for a federal bailout? "I couldn't agree completely with that," Sims said. "We're held up as peculiar and I don't think we're that peculiar." A bill raising the state gasoline tax languishes in the legislature but, as Sims points out, Missouri and Colorado have both turned down gasoline tax increases.

Pennsylvania's problem is exacerbated by the fact that it is so heavily in debt on bond issues sold to build roads. While some states, such as Virginia, chose a pay-as-you-go approach, Pennsylvania used bonds and now has annual debt service of $215 million, which consume almost half the state's gasoline tax revenues. There is no relief until the 1990s.

Most states do not want the federal regulations that would go with federal aid for maintenance, according to Henrik E. Stafseth, executive director of the American Association of State Highway and Transportation Officials (AASHTO). "The cost of paperwork would exceed the cost of maintenance," he said.

Nevertheless, Stafseth said, "there has to be either an improvement in the economics of maintenance or an increase in taxes on gasoline."

The problem extends beyond Pennsylvania's borders and beyond just the interstate system. The General Accounting Office reported last year that "highways are now deteriorating 50 percent faster then they are being replaced . . . We believe the deterioration will continue unless the revenue situation improves or the states increase the past percentage of highway construction funds used to improve the highways."

The condidtion of pavement is measured by highway officials ona scale of 0 to 5 known as the Present Serviceability Rating (PSR). A PSR of 5 is assigned to new paving. Paving rated below PSR 2.5 considered in immediate nedd of reconstruction.

A Federal Highway Administration survey last year found that only 4 percent of the interstate system then open to traffic had a PSR 2.5 or below. However, 23 percent, more than 8,000 miles, was rated between 2.5 and 3 - fair condition only.

Pavement in that condition will be in need of reconstruction in a short time, depending on the traffic volume, weather, and other factors.

Futhermore, the study said, the closer paving gets to an unacceptable PSR, the more quickly it deteriorates. Therefore, the less that is done to prop up older pavement, the more quickly it will fall apart.

Back on Interstate 80 near Berwick, Pa., federal engineer George Catsellis stood by the side of the road one day in September and pointed out an everwidening crack in the pavement to an unhappy state engineer he had in tow.

"If you would just get some asphalt in here and seal that thing before it freezes , you could save it," he told the state man, who shrugged helplessly.

The shulder had separated from the concrete paving and settled several inches below it, creating an obvious safety hazard for a driver who might accidently go off the road.

"What we like to see is an even, black joint where the paving meets the shoulder," said Catselis. "If that seal remains tight, nuch of the water that comes with rain and snow runs off and does not get in the pavement and freeze." Hydraulic pressures built up in repetitive freeze-thaw cycles are particularly destructive of paving .

As Catselis talked, trucks rumbled by at the erate of about three a minute, a noisy reminder that they are blamed for deteriorating freeways.

The finger-pointing starts with a statistic, developed by AASHTO, that it takes 2,500 automobiles to cause the same pavement damage as one legally loaded truck.

However, a recent study of federal highway data by the Congressional Budget Office said that in 1975 automobiles were responsible for 63.5 opercent of the costs of all federal aid highways, but paid 56.9 percent of the bill through contributions to the highway trust fund.

Trucks depending on their number of axles and whether they were pulling trailers were responsoble for between 0.1 and 10.4 percent of the costs and were contributing between 0.3 and 11 percent to the trust fund.

However, CBO said, the largest trucks - 4 and 5-axle diesel-powered semis - "have consistently underpaid because of the better fuel economy of diesel engines and their corresponding lower fuel tax payments." A 1975 study sfound that the largest diesel-powered combinations were still underpaying (by 33 percent of $650 per vehicle)," CBO said.

Those statistics, cited by either side of the debate to prove a point, all concern themselves with law-abing, legally loaded trucks. Not all truckers are law-abing and legally loaded.

Several states, Pennsylvania among them have been scored for lackadaisical enforcement of truck weight limits.

Last year, Pennsylvania installed its first set of permanent scales, on state Route 209 in the Poconos, a heavily traveled truck route that connects two interstates.

Shortly after the scales were opened for operation, they caught on fire. A trucker was charged with arson.

"That does lead me to believe that the truckers did not like the program," Sims said.