In Japan, there are taxi-like services that will drive your own car. 2 persons come in a taxi, one of them drives you in your car, and the other follows with the taxi (and picks back the first person once destination is reached).
Off the top of my head, public transportation, ride sharing, making streets more pedestrian friendly, denser zoning.
I had a great bar that was less than a mile from where I used to live. I rarely went because there was no way to walk there. No sidewalks in the neighborhood, no traffic lights, no bus that stopped near it. It's a shame. It closed shortly after I moved away after away. In the paper they said they just didn't get a lot of people coming in.
A great idea that I am in support of, but it's not a "realistic alternative", public transportation is politically fraught, expensive, and slow to build in the U.S. I'm not saying we shouldn't continue to strive towards it, but it's not happening any time soon in the U.S.
> ride sharing
This is the status quo.
> making streets more pedestrian friendly
Same issue as public transportation - slow, expensive, politically fraught, but also of dubious ROI in terms of preventing DUIs; nobody is going to walk 5 miles home from the bar because of streets that are friendlier to pedestrians. Of course, there are other worthy reasons to create pedestrian friendly streets, but they don't really represent a realistic alternative to someone prone to intoxicated driving.
> denser zoning
Again, not really a realistic alternative, zoning issues are politically and economically contentious at a level that transcends concerns about drunk driving and yet the needle on that issue barley moves due to NIMBYism and entrenched special interests.
Such as?