A bill to amend title 23 of the U. S. Code to authorize the selection and improvement of certain priority primary routes.

Permits high traffic sections of highways on the Federal-aid primary system which connect to the Interstate System to be selected by each State highway department for priority of improvement as supplementary routes to extend and supplement the service provided by the Interstate system by furnishing needed adequate traffic collector and distributor facilities as well as extensions.

Provides that such priority primary routes selected shall be improved to geometric and construction standards for the Interstate system, or to such other standards as may be developed cooperatively by the Secretary and the State highway departments in the same manner as are standards developed for the Interstate system.

Authorizes appropriations out of the Highway Trust Fund of $300,000,000 annually for fiscal years 1974-1975 to carry out the purposes of this Act. (Adds 23 U.S.C. 145)