I was on the Amalfi Coast in May 2014 for four days. We also planned on using public transportation as there are buses and bus stops all along the drive and it seemed like a logical option. However, once we got there, we literally had to walk everywhere.. We went to Positano early one day and could not get a bus back to Praiano because every bus just flew by maxed out with people. We walked the entire distance back! We laugh about it now, but if I ever go again, I will hire a car service. The car service is pretty expensive for one couple which is why we didn't make that arrangement, but if you can share the expense 4 ways, that is the best option.