The line dynamics itself is just Hooke’s law stuff – basic physics. Took some experimentation to get a smooth curve drawn through a series of points (basicaly, the control points of your previous and next points need to be in line).
The cars follow one of the line’s points with differing elasticity and damping, but the real pain in the backside was drawing the dashed line via code, in crummy ActionScript. Luckily, I’m a persistent bastard 🙂 Read more about it on Bannerblog.
I created this microsite for Dare Digital back in 2005, to promote a competition running alongside BBH‘s Vodafone ‘Mayfly’ TV campaign. Users can create a mayfly with a personal message attached, which lives for just 24 hours and wanders around the environment. The best life-affirming message won a drive around Monza with Michael Schumacher in his Ferrari!