From Wikipedia
I think they should have picked a shorter name and a different name so as not to confuse it with the Lima Metro, but oh well, what are you going to do? Transport in Peru isn't one of the best in the world, in fact it's not even good, it's horrible. They don't have buses, but combis, which are super old buses with card board where metal used to be and parts of the floor missing.Fare takers with filthy fingernails, people doubled over in mini vans, pushing, shoving, different fares, stopping when there's a green light, going when there's a red light, buses that look like they should be used for scrap metal, and buses competing with each other for passengers are just a few of the many problems you have to deal with.
So they decided to create an organised system back in 2006 called El Metropolitano. Fastforward to now, 7 years later there's one line with 38 stops. Not much, but it's something. It's expensive though. At 2 soles per ride it'd double what many combis were charging. And forget about paying just a china (50 cents) for a short ride. There are no fare takers, Peru has entered the 21st century and is using cards.
The good news is that they're making an effort to be fair and organised, the bad news is that they've got a way to go.