Modular Urban Board Preview

Inspired by the really impressive ShadowRun 15mm board on Clear Horizon, I've decided to start my own modular urban board. The pieces are 20x20cm squares, and the first 'set' roughly corresponds to what one can find in Miniature Scenery City Grounds set.
Below you can see an example of 4x4 layout - I've done the basic work on the streets (acrylic filler was used to hide the wood texture) and started gluing homemade plasticard sidewalks down.
(Click the pictures to see the bigger versions)

Some detail shots:

I plan to airbrush the board using going from light gray through ivory to white. The streets will be sprayed black and the raised platforms will get some stencil markings with dark green.