Four pints of beer would put you well over the blood/alchohol limit for driving in the UK, in fact little more than one pint would do so. The limit is 80 Mg of alchohol per 100 millilitres of blood (.08 percent in US terminology), and you can in fact be busted below that limit too incidentally, since any alchohol intake is regarded as 'aggravating' in legal terms. The limit equates to about one and a third pints of average lager (aka a pint of Carling or some such is about all you can legally get away with, and even that willl be detrimental to your driving ability). Drinking and driving is for assholes, just don't do it, you may very well kill someone, and possibly yourself too; nobody needs a drink that badly, have a drink when you get there if you have to.
And incidentally, I'm not against alchohol, I've just got in from a night in the pub as I type this, but I went there and came back on a bus, and saw my buddies off in a taxi. Like airline pilots, 24 hours from bottle to throttle is my rule, and I suggest you adopt the same thing, and especially on a long distance drive.
Al
Quite right regarding drink driving but in this case fran1 is talking about a rail journey made from Brussels to Preston (and back) with a 1.5 hr. wait in London, no problem with having a few pints there!