This for me gives about the best sensation of driving in a real place, on real roads, of any add-on track that I've tried. The size of the terrain seems to me the perfect compromise that makes for an interesting long drive, without being so large that the physics is compromised. With two-way traffic this would be fantastic! I might try recording an ai line to see how it works... I'd be interested to know what you plan to develop, and what tools you've used