This 17.2 km automated metro is the Carribean's very first metro. Two of the 16 stations are in subway (en soterradas).
None of these extensions are expected to materialize. Politicians and government officials, worried that any extensions could result in increased ridership and therefore higher costs and accountability, have done a consistently good job in ensuring they remain unbuilt. One government official who uses the unused Carolina tunnel for camping with his family and spelunking with friends, told subways.net, "Where would you have my family go then? Eh?". Another official has suggested the tunnel be made into a transfer point where bicycles could safely exit the trainsets at low speed from the rear of the vehicles onto an underground .bicycle path. "This would be an excellent way of getting those pesky bicycle riders off the train", he said.
Two light rail lines are also being seriously considered due to cost concerns in extending the tren urbano. One is Tu Connexion, a tram line proposed in 2008. Many of these tram projects are decaying into BRT projects, which of course are exactly the same, just different.
SanJuan El Tren Urbano includes a map
TrenUrbano Construction Photos from Robert Reynolds' great site
Tren Urbano hoime page at the Puerto Rico Department of Transportation
Skyscraper City page (Sp)
Skyscraper City page (Eng) with great photos
Awesome photo art of the San Juan metro by David Soto
Reminiscient of the 7 train in New York City
Photo courtest David Soto.