and on this note, i have to wonder what the op is proposing in its place? (that as long as they are of a certain age, they should be allowed to operate a motor vehicle, or any other dangerous piece of moving machinery, under whatever physical or mental condition they might happen to feel like it? that ought to be fun to watch. through a remote video link, from someplace safe, a loooong way away.)
I'm convinced its about both. But because its true the money is counted upon (partly to improve public safety on the road further) doesn't of course mean its in no way about safety and righteous penalties. That would be a rather black and white claim to a imo nonsensical extent.
The problems lie in certain situations... A drunk living on 5th avenue in NYC wants to go home. But at the moment, 5th Ave is closed to vehicular traffic because the president is in NYC, someone is going have to be able to reroute, and make sure the drunk gets home without the vehicle actually getting there. Someone not intoxicated, like a cab company employee, that the drunk should have used because he knew he was intoxicated.
a robotic taxi would know better then to try and drive on surface streets in a place like new york. how is it not obvious, that the car, self driving or not, is totally impractical anyplace you have that level of population density. but which is the topic? is it transportation technology (the one i'm interested in), or how to get people with impaired judgement from place to place without killing themselves and each other? or is it just an excuse to rag on how a government that results from our cultural values does things? if the problem is about impared people driving cars, if you're going to have mind altering substances sold by the dose, in places where the only way to get to and from is by driving a car, then how can you possibly expect to not have impared drivers, no matter what laws nor how vigerously enforced. there is this thing called logic. sometimes it can find solutions. it might even be worth trying sometime. robotics is fun. but making a car robotic doesn't solve the myriad problems created by the car, and thinking of transportation entirely, or even primarily, in terms of it. if you're going to have boozoriums, as some people seem to think you must, then just require them to be located withing an easy stagger of a trolly stop. and don't put streets to drive cars on, where they're going to be too jammed up with them to be useful anyway. the space they occupy could be filled with vegitation that produces oxygen, instead of pavement that makes the local micro-climate hotter and less comfortable.
Honestly, you would be surprised just how many impaired drivers (alcohol or otherwise) there are out there.