Thanks for the advice, Joe. In this case, the road data is from a national forest, where the road system, and network model, is very simple. In short, I know of no case where there is a bridge crossing another road. Also, if you ignore campground loops, there are no one way roads, and for the most part, no stoplights and very few stopsigns.
At this point, we are just looking to answer some very simple connectivity questions. However, we are likely going to look to integrate forest roads into a larger network of roads. For the moment, I am getting my feet wet in this extension, with the idea that sometime soon, I will need to understand much more than I currently do.
Any ideas for where to go to get smarter on this topic?