Nothing too much different to add to the above. I'm a WC (well, Exton) native. Taking the PA turnpike across is probably the easiest way. You DO NOT want to drive Route 30 for any length of time in PA. The Downingtown exit on the turnpike, then south on Route 100 will take you directly into West Chester. It will take, unless you do it at 3 AM, about an hour for that last 12 miles. Trust me. Traffic light every 60 feet. It's horrible, compared to what I remember from the 60s growing up. West Chester has also gotten quite built up in the last decade or two as well. If you are headed to the southern end (e.g., the college or whatever), take the US Route 202 Bypass AROUND WC rather than driving straight through it, which can be a horror in a car, much less a truck and 5er.
Go here - pics of the turnpike from around New Stanton area to Downingtown, then south to West Chester as described above. Last August's final leg home.
http://lens-flair.net/blog/mini-vacation-day-9-homeward-bound/