A piece of red tarmac and a piece of black tarmac in a bar arguing over who is the hardest:
Red tarmac - "I'm hard, me! They put me down at bus stops so huge heavy buses can stop without skidding"
Black tarmac - "I'm harder! They put me down on motorways and thousands of vehicles a day run over me"
Just then a piece of green tarmac walked in
The barman whispered frantically "Shut up you two this guy is a nutter and really is hard. He's a cycle path!