I am not very sure, but I think this expression can be used for the first trip of any means of transport and today we are celebrating that the tramway, underground, tube or whatever they call it, is at last working in Granada.
The 'metro' has started today!!
We have been suffering the inconvenience of its works for 12 years!!
I am really excited. It means so much for us, the people who live in the outskirts of Granada!!