I've probably mentioned this before, Helen, but a friend joined our group in the bar, and proudly showed us his new hand-made sandals, the soles and heels of which used recycled car tyre for its hard-wearing properties. Then someone noticed that he had less than 3mm of tread (which is illegal under the Road Traffic Act). Much discussion ensued on whether he might be arrested for being drunk in charge of feet, and be banned from walking for three months.