Maria Peiró
Metro since 2003
Oporto has has a metro since 2003 and currently there are 5 lines with 2 more are under construction. It uses the Andante card with an embedded computer chip, thus Porto is the first city to use public transport with low cost, contactless tickets. So, the user keeps the card (in their purse or wallet) only having to pass through the scanner to validate the trip. I took the Metro from Porto Airport to the train station and a very nice subway worker helped me buy the ticket and explained how to use it. I found no problems.