SR 306 and SR 9 are then co-signed on their way northeast toward the community of Coal Mountain, before SR 306 departs SR 9 and travels to the east to its interchange with US 19/SR 400 at exit 17, which is the northernmost interchange of SR 400's controlled access portion.
After being co-signed on their journey northeast toward Coal Mountain, SR 306 separates from SR 9 and travels east to its connection with US 19/SR 400 at exit 17, which is the northernmost interchange of SR 400's controlled access section.