http://www.ourlaughingplace.com/aspx/twiz.aspx#.VCIKTGK9KK1
I just stayed at the BWI last month and used a rental car to everywhere but Epcot and DHS (even though I did drive there too on Fantasmic night knowing the boats would be packed at closing).
The longest drive I made was from the MK to AK and it was about 12-15 minutes. Most trips are under 10 minutes.
I also mapquested a few point A to point B trips that I knew we'd be taking and the estimated times were very accurate.