Road signs are very clear for parks. For resorts, the signs often show a resort area rather than a specific resort: Epcot Area Resorts, or Disney Springs Resorts. The route to the Epcot Area Resorts is not always the same as the route to Epcot, for example. Once you get closer to a resort area, the signs point to the individual resorts.
Two of the major roads, Word Drive which is the entry to the MK area, and Epcot Center Drive which is the entry to Epcot, are freeway-like, but the speed limit is only 50. The only problem area right now is exiting the property on Epcot Center Drive to I-4, where the lanes and signage are somewhat confusing due to major reconstruction.
It's good to remember that it's virtually impossible to get truly lost on WDW property, so there's never a cause to panic. If you miss an exit, you can usually get off at the next one and signage will direct you to your destination. Or if you feel confused, just pull into any parking lot or resort entrance and ask the parking or security cm for directions.