If you want to know something as simple as who heads the National Highway Traffic Safety Administration, don’t bother to ask the safety agency’s communications office. Without special permission, officials there are no longer allowed to provide information to reporters except on a background basis, which means it cannot be attributed to a spokesman.

Without such attribution, there are few circumstances under which most reporters will report such information. This makes for interesting dealings with the office charged with providing information about the nation’s top automotive safety agency.

So, I will end the suspense about the boss’s identity. The administrator is Nicole R. Nason, who took over on May 31, 2006, after she was appointed to the post by President Bush.

And it is she who put the big hush on one of the government’s most important safety agencies. I found this out recently when I asked to talk to an N.H.T.S.A. researcher about some technical safety issues in which he had a great deal of expertise. Agency officials told me I could talk to the expert on a background basis, but if I wanted to use any information or quotes from him, that would have to be worked out later with a N.H.T.S.A. official. The arrangement struck me as manipulative, and I declined to agree to it.

It seems that Ms. Nason has adopted a policy that has blocked virtually all of her staff — including the communications office — from providing any information to reporters on the record, which means that it can be attributed.

As an alternative I was told I could interview Ms. Nason on the record (instead of the expert on the subject of my article). I declined, failing to see how her appointment as administrator — she was trained as a lawyer — made her a expert in that subject.

When I said I would like to talk to Ms. Nason on the record about her no-attribution policy, she was not available.

The agency’s new policy effectively means that some of the world’s top safety researchers are no longer allowed to talk to reporters or to be freely quoted about automotive safety issues that affect pretty much everybody.

“My God,” said Joan Claybrook, who was N.H.T.S.A. administrator from 1977 to 1981 and is now president of Public Citizen, a consumer advocacy group. Given that N.H.T.S.A. is the leading source of automotive safety information in the United States, its researchers are public officials and people are entitled to “know what information they have, whether it is on paper or in their heads,” Ms. Claybrook said.

The policy of allowing information to be attributed only to political appointees is intermittently enforced around other parts of the Department of Transportation, including the Federal Railroad Administration. But it is a radical change from the way N.H.T.S.A has operated for at least 20 years. In the past, reporters could talk to its experts and the agency was proud to discuss its research and accomplishments.

Ms. Nason felt it was necessary for N.H.T.S.A. to have a “central spokesperson” and “we were finding a lot of stuff did not need to be on the record,” David Kelly, her chief of staff, told me. He also insisted, after our telephone conversation, that he did not want to be quoted and had intended to speak only on background. (My notes show no such request.)

So that central spokesperson is Ms. Nason, whose previous job was assistant secretary for governmental affairs in the Department of Transportation. “In that position, she was responsible for oversight of congressional affairs, coordinating all legislative and nonlegislative relationships between the D.O.T. and Congress,” according to her N.H.T.S.A. biography. If she has any experience in keeping a Congressman from skidding out of control, that could come in handy now that she is speaking for an entire agency of seasoned safety experts.