Path animation on canvas

What is this?

Using javascript to define an SVG path, then use this path as the basis for animation.

Options:

The path is Silverstone racetrack which I drew and exported using Flash, then quickly reformatted the data for this system.
This path is px long.
It is defined by the following string:

This simple example uses a linear progression to animate the dot along the line, but it could easily be eased.

Methods:

I have written a set of familiar drawing API like methods to contruct the SVG path.
Not strictly necessary for the initial banner purpose, but will be crucial for any interactive line drawing:

Thoughts for development....