Airline pilots, train engineers and truck drivers subject to federally mandated drug screening will soon be tested for a range of opioids under a new rule issued Thursday. While transportation workers have long been subject to random screenings for various drugs, the list didn’t include the synthetic opioid pain killers that have helped lead to a dramatic spike in addiction and overdose deaths in the U.S. Following through on a proposal released on Jan. 23, the Department of Transportation published a final rule adding the drugs hydrocodone, hydromorphone, oxymorphone and oxycodone to a list that already included marijuana, cocaine and heroin. The new testing rules take effect on Jan. 1. President Donald Trump declared opioid addiction a public health emergency on Oct. 26 and that class of drugs has begun to show up in post-accident drug testing, such as a 2016 Amtrak rail collision that killed two workers, according to the National Transportation Safety Board. Drug testing required after an accident typically screens for more substances than the random tests that transportation workers get.