From reading the PDF files, it looks like cover is really important (tell me if I'm wrong, but I didn't see much besides saves for cover noted...).
If this is so, you might want to consider putting pillars or some kind of long, but not too tall bits of terrain there.
(Ad banners? Junkyard? Parking lot?)
I can add small movable barriers and suchlike to the roads, as cover can be important for squishier units. Heavier armoured units like Exo-mechs can risk standing out in the open, assuming a nearby enemy unit doesn't have anti-amour weapons.
If I had given myself more space, I could've done catwalks, but I think with the current design that wouldn't look so good.
Keep in mind the shop buildings will have doors and windows cut into them, which'll act as fire points and cover :3
BTW, the game sounds interesting, but I'm wondering how it plays.
It sounds mechanically similar to 40k or Infinity, but there's no melee?
Its closer to Infinite than 40k, and works best when both sides have roughly the same number of units. There isn't a point where one player will be sitting around doing nothing, as at any point during an enemy units' move, your units could spot them and open fire. Reaction fire is a constant element unlike Infinite where I think a model can only react once per game turn?
You can also play on smaller game boards, considering this is there demonstration board
I played a demo game with the devs at Game Expo 2016 on that board. It was made smaller (removed the higher building sections) for easier transport, but most of the game occured on the base and 1st level. Street level seems to be the most hazardous place to be.