Only found out about these minibuses a month or so ago, if your in Pattaya these are a great way to get to Rayong or Chonburi, it costs around 60 to 80baht per person but they are quick and there seems plenty of them, ie only ever a few minutes wait at most.
They stop just after each set of traffic lights in Pattaya to pick up and drop off passengers, sometimes there is standing room only so they have passengers standing, not sure if that is a good idea on a minibus, some have the front signs, Rayong Chonburi in English but most have them in Thai.