Richard O. (Dick) Bennett, 73, secretary and treasurer of the Insurance Institute for Highway Safety from 1959 until his retirement in 1971, died of cancer Sunday at a hospital in Clearwater, Fla.

Mr. Bennett began his traffic safety career in the early 1930s in his native Lincoln, Neb., with the police department's traffic safety division. He then was a traffic safety specialist for the Greyhound bus company in Detroit and for the National Safety Council and the National Association of Automotive Mutual Insurance Companies in Chicago before moving to the Washington area in 1959.

In 1966, he received the Paul Gray Hoffman Award for "distinguished professional service in highway safety."

Mr. Bennett graduated from the University of Nebraska and was a Kemper Growth Fund Fellow at Northwestern University in Illinois in 1936 and 1937.

During World War II, he served in the Army in North Africa, Sicily and Italy.

Mr. Bennett lived in Washington and in McLean before moving to Clearwater in 1971.

He was a member of the International Association of Police, the Metropolitan Washington Board of Trade, the American Society of Safety Engineers, where he was president in 1966, the Institute of Traffic Engineers and the International Club of Washington.

Survivors include his wife of 52 years, Eleanor T., of Clearwater; two sons, Marc L., of Reston, and Richard C., of Oxon Hill; a sister, Elvira Blue, of Fort Pierce, Fla., and seven grandchildren.