"Five years ago I got interested in interactive diagrams and made a few, but then got distracted by other things. I wrote a blog post about why I was interested in them. I've recently become interested in them again." - Amit Patel from Bookmarklet

You should add the driver's forward view and draggable cars in adjacent lanes. Most people adjust their mirrors to minimize the number of blind spots (you can get it down to 2), rather than the number of blind spots big enough to fit a car (you can get this down to zero). - Seth

Seth, that's a good idea. Lane markers and cars would help people get a sense of spacing and whether any part of the car is visible. But then I need to add bikes! :) - Amit Patel