It won't help anything. There are already new trains. They are shorter and the air conditionning does not help the awful smell that lives there: Floors are not cleaned properly.Another problem is the flux of people in the metro. As soon as one train is even 1 minute late, you end up being squeezed like a sardine in a can. I always thoought that the metro administration is trying to kill people more than help them. Even animals are protected by law from these conditions of transportation.