Auto Map Terrain Generator

I realize lots of people do enjoy making their own maps.  In some cases you just want to give it a general idea and 'GO'.   Options to upload the different tile types.   Roads are biased to have at least two roads on either side, and a % of possible 3rd. Buildings to be about X by Y in size Plant life (Trees, bushes, ground foliage).  A overall number, or option to control the % of the different size type. Dungeons can have 'doors'.  Option for door type (difficulty to break) Choice of tile shape  (square, hex, etc)

I think the complexity of what you're asking for may be beyond the scope of Roll20. There are a number of dungeon designing tools available online, including randomly generated ones. for example, <a href="http://donjon.bin.sh" rel="nofollow">http://donjon.bin.sh</a>