A representative of the National Transportation Safety Board examines the confusing and inconsistent manner in which the Federal regulations on alcohol and drug impairment are developed and applied in the various transportation modes. Representatives of the Federal Railroad Administration, the Federal Aviation Administration, and the Federal Highway Administration testify on the extent of drug abuse in the transportation industries their agencies regulate and describe some of the means used to prevent personnel drug abuse. Representatives of management and unions in the three transportation industries under consideration discuss the advantages and disadvantages of Federal regulations designed to control drug and alcohol abuse among personnel in these industries. Methods currently used in these industries to detect personnel drug abuse are reviewed by the witnesses.