I've always heard that Manassas is a difficult place to tour and I'd agree with them to a point. As the pictures show there is a ton of traffic through the heart of the battlefield. It seems if you stay off the Warrenton Turnpike (currently Lee Highway US 29) and the Sudley Road (currently state highway 234) you should be fine. These two pictures show the Warrenton Turnpike and it was somewhat difficult to get on and off this highway. Luckily people did allow us on and off when we needed, primarily because they were facing bumper to bumper traffic and thus allowing one more car space wasn't the end of the world. Unfortunately there are not many side roads in the park so you will be on these two main roads a lot for touring. When Mike and I left the park in April we took a side road near the Stone Bridge to get back towards Leesburg and it eventually turned into a gravel road. It was pretty weird to be that close to all that traffic and be on a gravel road.