Why you shouldnt smoke your profits

[3 Sheets To The Wind]

Ok, forgive me, but I'm just an ignorant Yank and don't understand real English, but WTF is a "layby"? I've only ever heard this once before in a Roger Waters song and always wondered. I thought it was like a highway rest area but doesn't sound like it from what you're saying.

It's a wider section of the road, that you can't drive on, that you can pull over in.
It is like a rest area on a highway/motorway, as you just pull into there, leaving the road free for cars to pass