THE subway crash in New York City last week that killed five passengers and injured more than 200 people highlights again the need for random drug and alcohol testing of transportation workers in "safety-sensitive" jobs. According to the police report, the motorman of the train that careened off the tracks had more than twice the blood-alcohol level defined as drunkenness in New York.Under US Transportation Department regulations issued in 1988, specified workers in the airline, railroad, trucking, and other transportation industries are subject to random drug - but not alcohol - testing. However, a federal court exempted urban bus and subway drivers, ruling that the Urban Mass Transit Administration, a federal grant-awarding agency, was not empowered by Congress to issue safety regulations. A bill sponsored by Sens. John Danforth (R) of Missouri and Ernest Hollings (D) of South Carolina would subject all transportation workers in safety-sensitive jobs, including mass-transit operators, to random testing (as well as other scheduled testing) for both drugs and alcohol. Repeatedly passed by the Senate since 1987, the bill has languished in the House of Representatives owing to opposition from labor unions and civil libertarians. The House should promptly enact this reasonable legislation, in the interest of public safety. We have previously stated our misgivings about calls for widespread, indiscriminate drug testing; such testing raises concerns about unnecessary invasions of privacy. But in the case of transportation workers, public safety deserves priority. And random drug testing in the military and Coast Guard has proven to be an effective deterrent to substance abuse on the job. It's vital that, as the Danforth-Hollings bill provides, transportation workers be tested for alcohol as well as drugs. Alcohol - legal and readily available - is far more likely to be abused by employees in safety-sensitive transportation jobs than illegal drugs are.