Upon crossing the river , the highway enters Mount Pleasant at grade .
Upon crossing the river , the highway is signalized for several miles up through the second interchange with Interstate 526 and connecting roads to the Isle of Palms and Sullivan 's Island .
Upon crossing the river , the highway enters Mount Pleasant at grade and is signalized for several miles up through the second interchange with Interstate 526 and connecting roads to the Isle of Palms and Sullivan 's Island .