The US Department of Transportation has their own set of polices that organizations must adhere to in order to keep a healthy workforce and avoid penalties.
Drivers must complete a DOT physical and companies must comply with the DOT’s random drug and alcohol testing policy. For 2024, FMCSA drug testing rates are 50% and alcohol testing rates are 10%. Therefore, an employer with 100 safety-sensitive employees would have to ensure that 50 or more random drug tests and 10 or more random alcohol tests were conducted during the calendar year (US Department of Transportation).
You can find more info about current testing rates at https://www.transportation.gov/odapc/random-testing-rates