Heading out for a drive this weekend? Live near Lake Biwa in Japan? Then head over the O-hashi ('Big Bridge') and sing along with the music your car will make as it runs over the 'Melody Road'. These attractions (distractions?) - created by carving ridges into the surface of the road, causing your tires to play 'music' - have popped up all over Japan in recent years (here's an English-language news clip on the phenomenon). But if you are a road engineer, and are thinking of perhaps making one of these, you had better do the math properly, something the engineers on a similar project for a Honda commercial spectacularly failed to do. (Analysis of what went wrong on this interesting blog post).