A Train In The Sky: Fighting Sprawl With Rail

[Puerto Rico's] planners are attempting something extremely difficult: altering a landscape produced by one type of transportation, the highway, by introducing a different type of transportation, an elevated train line. The risk in this type of urban surgery is that the patient will reject the alien transplant. Parts of the line travel through older streetcar suburbs, which have remnants of a traditional urban fabric. But the bulk of the project goes through postwar highway-oriented development, which is the most difficult to adapt to mass transit."