OK. I was pretty sure I knew the word but looked it up to make sure before I committed to this. Anyway, if you have ever ridden on a train you know the clickety clack sound of the wheels running on the rails. This is caused by the shifting of the rails at the junction point of two rails meeting. Not very romantic but the whole train travel experience must be taken as a whole for it to work at all. After ridding the rails in Europe for a number of years I'm sorry to say that the system in the US is barely ride-able and needs a Major overhaul.