The A406 is enjoying a pint in his local when the M25 walks in and, as usual, starts hassling him. Buy me a pint... get me some food... stop crying... blah blah blah...
Half an hour later the M25 is still hassling him and bragging about how hard and big he is(!) when a thin red strip of road wanders in. At which point the M25 darts out the back.
The thin red-strip has a pint and leaves, after which the M25 timidly returns back in.
"Wow" starts the A406, "What the heck was that all about? I thought you were all double hard!"
"yeah" says the M25, "but that guy was a cycle path."
I thank you, I'm here all week.