I've been planning for a long time to mix data from OpenStreetMap, some digital elevation model (heightmap), satellite imagery for textures, and cook a racing/cruising game where I could drive around familiar parts of the city.
OpenStreetMap contains very nice and detailed maps of all the locations I've checked, so I imagine it won't be so hard to download data for a specified region, like Boone County, Nebraska and stuff them into the game. I could generate buildings in 3d somewhat, as they have defined contour in OpenStreetMap. Roads would be the easiest thing to do as they are the core part of OSM.
What I'm worried about is the game/"simulator" part. I don't know where particularly to start. I suppose I would have to generate a lot of this world during the loading / on the fly. I don't even know if there is anything racing/vehicular-like out there available to use, except for the XNA Racing Game. I'm employed as C# developer, so I'm skilled in that language, but I'd be willing to venture into Python or something similar, if it would increase productivity in this hobby project.
Can you recommend me some engines worth looking into?