I saw that option Ceist Beag but have heard of people being billed for journeys (after registering for a video account) that they simply didnt take... combine this with horrendous customer service using the phone number (no answer, ringing out) and poor correspondence when customers lodge issue and / or complaint I think its easier all round to have as little contact as possible!
Think I'll keep it simple and pay in person, only one return journey expected.