The system is actually remarkably simple. You walk into the club,
Then, it’s your job to party down. have a few drinks, get crazy, and when it comes time to have a pee, a little gadget in the urinal actually measures your pee for a high alcohol concentration. It then connects to the RFID card in your pocket to program it with a binary response: either you’re too drunk to drive or you’re all good.
When you try to get your keys back from the valet, you scan your RFID card which tells you you’ve had too much to drink and you should catch a cab, or you’re ok to drive and they hand you your keys.
I can only think of two flaws in this plan: either you don’t go to the bathroom in the club and leave with a skinful of booze and a full-bladder, or you sober up between peeing and leaving but your RFID card doesn’t update to indicate you’re good to drive.
Other than that, this is a great system.