When I was working on the continent some vehicles had aloclock systems fitted, so you had to breathe into them to start the engine. I’ve worked with random testing for years and years and honestly it’s not something that I’ve ever really been bothered with. End of the day, anything that takes someone who is willing to flout alcohol/drug limits and step until a large (or any) vehicle off of the road can only he a good thing.
Lot I’m at now uses an outside company to select someone.