A piece of grey tarmac is in a bar with a piece of red tarmac.
A piece of green tarmac walks in, grabs red's drink, and saunters off.
Red tarmac, outraged, gets up to follow, but grey tarmac says, 'Leave it.'
'But he stole my drink!' fumes red.
'Yeah', says grey, 'but mate, believe me, you don't want to mess with him. He's a cycle path.'