Com de costum, estava aborrit al treball i m’he dedicat a mirar internet, i navegant navegant, m’he trobat una pàgina de guies turístiques de Barcelona on fan la següent advertència:
TIP
Will You Get Caught Out? Many times tourists put their ticket in the right hand side slot of the ticket validation machine and then try to enter on the left hand side turnstile only to find they can’t pass through the turnstile. Why not? Because you have to enter your ticket on the left hand side and enter on the right turnstile!! Watch out for this. There is a good chance you could get caught out! The rule for turnstile metro entrances is Ticket on the left, pass through on the right.
But just to make things a little more complicated… If you find that the ticket validation machine has glass sliding doors instead of a turnstile you have to enter your ticket on the right hand side and pass through on the left! - You will find sliding door -type entrances to the metro at Catalunya and Barcelona Sants station for the RENFE train entrance.
M’ha fet molta gràcia, perquè és cert que a la que et despistes, et pots confondre, perquè això de que a alguns llocs s’entri per la dreta i a altres per l’esquerra és molt liós.
Ref: http://www.barcelona-tourist-guide.com/en/transport/barcelona-metro.html