if this works like the ones for alcohol, it is physically impossible to drive it safely. the bias is built in & you will swerve, hit shit, & the brakes will NOT work when you use them because there is a delay built into the system. this is why they use a simulator, the game is rigged. if they wanted to know the truth, they would let you get high & drive a real damned car on an enclosed realistic course. but then, that is not what they want...