A few years back I did odd-timed shifts and would regularly give a lift home to a colleague who did not drive. When I asked him why (he was in his late 50s) he replied: "I like drinking too much". So, a responsible drinker? He always had a plastic cup of "water" (Russian) in his desk, but he seemed to be able to work without any problem. However, I can't remember how many times he actually fell out of the car when I dropped him off.
In the UK, you can ride a moped (under 50cc and top speed of 30mph) at 16. You can get a provisional licence for a car at 17; you have to have L-plates front and rear and always be accompanied by someone who is over 21 and held a full licence for three years. Same age for motorcycles up to 33bhp. Most other vehicles - large lorries, buses, larger motorcycles it's 21 (although 18-year-olds in the armed forces can drive trucks of any size with a trailer).
British government link to what you can drive when.
On topic - age to buy alcohol here is 18, but many shops and bars insist on ID "if you look under 21" or even 25 in some cases.
