Many tourists going to or coming from the airport make use of the X buses because they find the service convenient and cheap. In the absence of suitable storage space, tourists place their luggage either in the corridor of the bus or on the seats, thus depriving other passengers of seats.
I suggest that a number of buses be assigned on the X routes with adequate storage space for heavy luggage. Four or six seats from the front rows should be replaced with shelves for luggage.