Not sure if the OP is being updated, or if this is mentioned elsewhere in the 9 pages of this thread, but Phoenix's Northwest extension Phase I is also under construction (to go along with the Mesa extension). 3 miles for a total of 6 miles U/C. The Northwest Phase I expansion is actually 3.2 miles, but who's counting that closely.
http://www.valleymetro.org/projects_...thwest_phase_i