Probably because most cities in Florida aren't big enough, apart from Miami. Miami is a large city and could certainly benefit from a subway, but it's also fairly spread out and congestion hasn't been as much as a problem. Compared this to Washington DC (too historic to build massive freeways through), New York City (too big to solve traffic problems with freeways alone), Boston and Los Angeles.
Additionally, Florida is a very low lying state thus any hole you dig will fill with water very quickly (most houses in Florida don't even have basements). Florida is also mostly sand which is easy to dig in, but is not very sturdy.
underground
Underground.
Subways are also called 'theUnderground' ... In New York City they're Subways, but in London, they are The Underground.
Subways allow commuters to travel to the city via trains that go underground so as not to interfere with above ground transportation.
Subways
there is aior planes,trains and subways
Subways are built in crowded cities because the roads can not handle the traffic. So long as people can get around on the roads with buses and cars, nobody builds underground railways because they are very expensive.
Do you mean underground railways? If so, yes. The world's first (in London) opened in 1863.
The underground construction employs urban miners who go by the slang term of Sandhogs.
Paul Elford Garbutt has written: 'How the underground works' -- subject(s): Subways
Papa murphys and some subways
David Long has written: 'London underground' -- subject(s): Design and construction, Subways, History