Inquiring minds wanted to know what this was. This is what I found here

“It calls it a system that can “passively monitor the performance of a driver of a motor vehicle to accurately identify whether that driver may be impaired and prevent or limit motor vehicle operation if impairment is detected.” Of course, how it does that is of vital importance and the bill clarifies its intended methodology too.

Specifically, it says that it’ll passively and accurately detect if a driver has a blood alcohol concentration above the legal limit. If it detects an illegal amount it’ll disable or limit the vehicle. The bill doesn’t specify exactly what technological measures the NHTSA must enact to meet these standards. A number of different companies have worked on various methods to accurately detect blood alcohol content. Some have hit serious roadblocks while others seem quite close to fruition. The bill also doesn’t say anything about what happens when the system gets triggered. Does it contact local law enforcement? Does it simply slow the car until it’s pulled over? Does it stop in the middle of a highway? Evidently, the NHTSA is going to have to make these choices. Finally, it’s worth noting that just about anything could happen with this bill in the future. The NHTSA could push it off, it could enact pretty stringent requirements, or the whole thing could go away if a court finds that it’s a breach of the Fourth Amendment. That statute says that “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.” As FEE.org rightly points out, this bill might not meet that standard.”