I actually read why it works here ... because there is no "open container" law in germany. Even the driver can drink while driving with the same limits applying (0.03 BAC). Occasionally, I see mini-bottles (0.2L) of champagne in the cup holders of a parked car.

I guess that makes sense as I can buy beer out of vending machines and at the university cafeteria with lunch (16 year old legal age limit.) However, on the bikes (280€/day rental for 10 people with 50L of beer), you get a company driver as well, who doesn't drink.

I personally wouldn't take one unless it was for a bachelor/stag party, as I'd rather sit by the water and have a beer or two.

FWIW, we also have a street tram that goes bar to bar and serves the local applewine.