They've been mucking about for months with the top end of Charing Cross Road, outside Tottenham Court Road tube station - part of the Crossrail project. But this curious sign again caught my eye yesterday: I've not seen one like it anywhere else. Is it 'live' rhyming with 'give', a kind of encouragement to be-the-traffic? Or 'live' rhyming with 'jive', like a high-voltage cable threatening instant chargrilled death? I was so intent on staring at the sign I nearly got run over.