The amount of roads is tied to the number of world objects slider I believe. X-Plane uses Open Street Map data to create the road networks. If they are inaccurate, the data we base it on may also be inaccurate as it is a volunteer project.
If the automatic crash reporter comes up, be sure to fill it out and send it in. For more investigation we'll need to see a copy of the log.txt from the main X-Plane folder from after a crash.