How do I draw two parallel poly lines based on only two points (similar to google maps traffic)

Question

I have a Polyline that is drawn from point A to point B, I'm trying to figure out how to draw two lines of a constant width that appear something like this image.

I only have two points, rather than four, I thought maybe there was a way to create four points, based on the two and then draw the corresponding lines, but I cant seem to get my head around it.

Any suggestions

Answer 1

I am currently trying to achieve the same thing, have two parallel polylines, but with different colors.

Have you seen this:

http://wtp2.appspot.com/ParallelLines.htm

It uses Google Maps v2 API, but it seems quite simple to convert it to API v3.