The Montgomery County Council voted Thursday afternoon to design a new south entrance to the Bethesda Metro station. This entrance would include an interchange with the proposed Purple Line, a rail link to Bethesda and perhaps to New Carrolton and beyond. The $5 million design appropriation doesn’t guarantee the construction of the Purple Line, which was approved by the Council in 1989, but which is unfunded and remains controversial despite widespread citizen support. The planned interchange merely assures that, if the Purple Line is ever built, it will have a place to stop in Bethesda.