Secretary of Transportation Brock Adams has selected Ralph Nader associate Joan Claybrook to head the National Highway Traffic Safety Administration.

A special assistant to NHTSA Director William Haddon Jr. from 1966 to 1970, Claybrook has endorsed the use of such passive restraints as air bags in automobiles.

She has been sharply critical of the auto industry and the Nixon-Ford administrations for delaying introduction of the air bags, which inflate instantaneously to protect drivers or riders when a crash occurs.

Claybrook's nomination must be approved by President Carter and the Senate. Since 1973 the director of Congress Watch, a Nadar organization that monitors Capitol Hill and lobbies for consumer legislation, Claybrook said yesterday the NHTSA post "is the only job I would have taken in the administration."

A graduate of Goucher College and Georgetown Law School, Claybrook worked briefly for then-Sen. Walter Mondale, now the Vice President, before joining NHTSA in 1966. At DOT, she helped draft some key sections of current motor vehicle safety laws.

Informed sources in Washington said yesterday the Claybrook selection is causing apprehension in the auto industry, not only because of her strong support for mandating air bags but also because she has devocated making public industry data previously kept secret at DOT.

A former DOT colleague described the 39-year-old Claybrook yesterday as "very dedicated" and "hard driving." Claybrook said she had been reluctant to depart her current role as an "activist citizen" but described the NHTSA role as "an important job."

Former DOT Secretary William T. Coleman Jr. decided against requiring auto makers to install air bags or passive seat belts in future cars despite evidence that such devices would save many lives. He expressed concern that such a mandate could backfire, in terms of public resistance.

Adams has said on several occasions that he questions the Coleman judgment and has promised to reassess the former DOT chief's agreements with several auto makers for an extensive project of testing air bags in the future.

In a Washington Post article last Sept. 1, Claybrook argued that "the life-saving capability of passive restraints is undisputed and the technical feasibity is assured."

Noting that mandatory use of air bags first was proposed in 1969, Claybrook wrote last September that delays were "orchestrated by the auto industry (primarily Ford and Chrysler) with the assistance of the White House and over the objections of the successive administrators of the NHTSA . . ."

The only issue about air bags, she asserted, is "political" - whether or when they should be required. She accused the auto industry of promoting delay through court action, appeals to Congress, "widespread advertising campaigns falsely condemning passive restraints, exaggerated cost claims, and on and on."