Nov 17, 2015 - 11:36 PM
Assuming you have the 2009 or 2010 version, under the "Topology" tab, the bottom option says "Add Ground." Click that, and then click on the edge of the block that you want expanded. You will need to do this multiple times for a large map, it will only add a block that is 2400 ft x 2400 ft. This also allows you to personalize the shape of the map to your liking.