Employers around the country have a bumpy road to follow as they navigate the ever-changing marijuana laws and regulations. Pre-employment and post accident drug testing have been challenged in courts in almost every state where medical marijuana has been legalized. These differing state laws create uncertainty for enforcing a drug-free workplace, even for safety-sensitive positions. In the transportation industry, these permissive state laws run directly afoul of federal requirements to keep the public highways and skies safe and drug-free. How can transportation companies manage drivers, pilots and other safety-sensitive workers while adapting to the increasingly legal use of cannabis - medical or recreational?