Virginia International Raceway(one of the best in country) NJ motorsports Park(brand new, still expanding) Sebring International Raceway in Florida(famous around the world) there's a new one in upstate NY, don't remember the name, but 100g a yr, so must be good. Limerock in CT, amazing facilies, all around great track.
90% of all nascar tracks have a road course within the confines, daytona(rolex 24hrs of daytona)
Texas Motor Speedway, ferrari uses the road course for it's Ferrari Challenge Cup every year.