Price was attractive as I booked online in advance The computer system was extremely poor. As instructed I a) collected a ticket on entry, and b) as I was leaving I approached the exit gate and inserted my ticket. Instead of recognizing my car number plate and allowing me to exit, the system demanded payment of twice what I had already paid. It took the gate assistant a good 5 minutes to verify that I had paid and to let me exit - by which time there were 20 cars waiting to exit as another customer had teh same problem. If you are going to rely on number plate recognition technology at least make sure it works!!!!