Before we gut Amtrak on the advice of Brock Adams and the Department of Transportation, Congress should take a very careful look at their assumption that dropping most of the long-distance passenger trains will ease Amtrak's financial burden. In fact, any alleged savings would be minuscule at best. For contrary to popular opinion, short-haul passenger trains do not have the money-making potential of the long hauls. Last year, for example, the Northeast Corridor was responsible for 27 percent, or $154 million, of Amtrak's deficit. Moreover, as recently announced, just bringing the Northeast Corridor up to modern speed and safety standards will now require $2.5 billion , a cost overrun of $750 million above the original estimate.

The economics of short-haul passenger service are as simple to understand as the analogy of the cab driver who refuses to go around the block when he can pick up a fare out to Dulles. At the Amtrak ticket window, the corridors are "around the block." People in the corridors simply don't ride far enough to generate enough revenue to cover the fixed costs of building and maintaining the system. Merely ticketing a passenger costs Amtrak $5.60. Similarly, corridors are fraught with all the problems basic to commutertype services, especially low ridership during midday and long periods of equipment idleness.

Granted, the Northeast Corridor carries 55 percent of Amtrak's ridership. But this statistic by itself is very misleading. It's not how many passengers, but how far they're going, that really counts. Thus the Northeast Corridor, with better than half the passengers, still accounts for only 26 percent of the passenger miles, while the long hauls, with only one-fifth the passengers, rack up a whopping 60 percent of the passenger miles.

A decade ago, when U.S. railroads were moving in for the kill on their passenger networks, transportation analysts decided that salvation for the passenger train lay in restricting it to routes of less than 300 miles where, the argument went, the passenger train could compete with the speed of the airliner. Unfortunately, this hypothesis became gospel before its economic and social short-comings had been scrutinized. In fact, Amtrak's single biggest success story is a long-distance train, the Coast Starlight, which runs the 1,200 miles between Seattle and Los Angeles. (It is also revealing to note that the Starlight was not included in plans for the original Amtrak system.) In 1977, the Starlight carried 440,000 passengers, nearly 2 1/2 percent of Amtrak's total annual ridership.

The problems of the long-distance trains have not been innate, but induced. For example, Amtrak management has delayed the conversion of rolling stock to more reliable heating and air-conditioning systems. Similarly, Amtrak marketing has slighted advertising the unique services and amenities of the long hauls.

Economically speaking, it is still they that offer the potential for a profit. Their operation is continuous, minus the costly switching, turnarounds and "down time" of the corridor trains. And because the long hauls are essentially "cruise" trains, their patrons are committed to riding much greater distances and at far larger fares. Nor is the long-haul passenger buying a frivolous service. Recreation has become very important to the nation's economy. The airlines, too, have long since learned that selling travel for pleasure is basic to setting standards of excellence for the businessman as well.

If Secretary Adams has his way, 43 percent of the Amtrak system will be dismantled for a bare savings of only 8 percent in required Amtrak funding for fiscal 1980. This huge discrepancy between losses and savings is in itself an admission that DOT has picked on the wrong trains for discontinuance. The cuts in either case would be false economy. Secretary Adams has jeopardized the credibility of the Carter administration's energy-conservation program, for instance, with its emphasis on curbing automobile use.

But even more disturbing, Secretary Adams has done nothing to resolve the glaring inconsistencies and double standards of national transportation policy, if indeed we have a policy. The airlines and highways have enjoyed both direct and hidden subsidies for decades. Why single out Amtrak, and especially its long-distance trains, as the fiscal villain in need of reform? Perhaps the Department of Transportation truly is the ward of the highway lobby, and is merely using the corridor myth as an opening wedge for scuttling all of Amtrak. If so, Congress must reaffirm its commitment to a fully viable, nationwide rail-passenger system.