Atrani is reachable by bus, or ferry, from Sorrento, Salerno, and Naples. If your arrival is by boat, you will land in Amalfi. From there, it is only a few minutes by bus, taxi, or by foot, and you will be in Atrani's town center.
The most scenic way to get to Atrani by car, is to leave the A3 motorway (autostrada) in Salerno, and drive along the S163 (Costiera Amalfitana).