there are a few items out there... including the Disney Cast Atlas (usually one for sale on ebay) showing roads and more...
they used to have a Transporation map of the entire Kingdom available...
most fold up maps have good detail (one is "Best Map of Orlando" from Barnes & Noble -- laminated folded map with good WDW, Universal, and general Orlando info... durable, good size (not overly huge)...
plus, the roads and exits to each park, hotel, etc. are very well marked when you're actually driving on-property.
or just use MapQuest... you can just put in the hotel name (even on-property WDW resorts) in the "Place Name" section and it will give good directions