Rocha sits on Ruta 9 and is well connected by bus with Montevideo, Punta del Este, Chuy, and the smaller towns of Rocha Department. It is the sensible transfer point if you are moving between the capital, the border, and the Atlantic villages.
A car is useful for Laguna de Rocha and the less frequent coastal routes. Buses can get you to the main towns, but the wilder beaches and lagoon access points are much easier with your own wheels.