Canvas wouldn't graphically scale as nicely. You could argue that SVG would be more appropriate, but this solution works on the old Android 2 browser whereas SVG doesn't.

Could probably ensure it fits in the window nicely though, with zooming etc. Seeing only the North-West of London on screen without scrolling is not as useful. I'd imagine it's damn hard to use on a laptop without two direction scrolling. Functional over pretty, I vote :)

I created a jQuery plugin to render subway maps using canvas a few years ago when I was getting into HTML5. Here's a demo http://kalyani.com/subwaymap and a detailed guide http://kalyani.com/2010/10/subway-map-visualization-jquery-p...

Same here. Was expecting some cool canvas demo. This is fine, but a lack of zoom out makes it decidedly less useful than other maps out there.