The National Highway Traffic Safety Administration will spend nearly $56 million this year trying to reduce drunk driving and increase the use of seat belts.

By comparison, the agency will spend about $48.5 million to encourage the production of safer cars.

Therein lie the priorities and beliefs of the Reagan administration in matters of highway safety. To wit: the government is reaching the limits of its powers to put safer cars on American roads; it must do more to produce safer drivers.

Consumer advocates and insurance industry representatives have accused the administration of giving lower priority to car safety as a sop to financially pressed auto makers, who have complained about the research and production costs they incur to meet federal safety standards.

For example, the critics point to NHTSA's decision last year to reduce manufacturing standards for front and rear bumpers designed to protect cars in minor crashes. The revised standards, lowered from 5 mph to 2 1/2 mph, may help auto makers save production dollars. But the change already has brought higher repair costs for car owners, according to the Insurance Institute for Highway Safety.

The administration is operating under "the mistaken notion that the sequence of events" in an accident "is more important than reducing or preventing the consequences" of the accident, said Brian O'Neill, senior vice president of the institute.

"The problem is that we know how to improve vehicles and we know how to improve highways. All it takes is will. But, in the case of the driver, it's not so simple. We don't know how to improve people," O'Neill said.

"We have gone as far as we practically can go with standards that would affect the manufacturing of safety in vehicles," NHTSA spokesman Hal Parris said yesterday. He said NHTSA Administrator Raymond A. Peck Jr. believes that "the agency, right now, can get the most good out of concentrating on improving the drivers . . . ."

Peck told a Senate Appropriations subcommittee last week that NHTSA is placing "greater emphasis on the highway safety portion of our mission, primarily on alcohol control and safety-belt usage," mostly because "alcohol abuse comprises the single greatest cause of accidents."

Peck denied that the driver-safety thrust of his administration is a diversion designed to take pressure off auto makers.

"The auto industry has spent a lot of effort on product improvement . . . . They're making cars as safely as they know how," he said.

He cited General Motors Corp.'s experimentation with new windshields as an example of industry interest in safety. The windshields are supposed to reduce facial cuts from windshield damage in auto collisions.

He said GM began the project without government prodding.