Production of next-generation Acela Express fleet underway
http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/production-of-next-generation-acela-express-fleet-underway.html
Rather than rolling stocks, Acela Express should think about newly constructing tracks only for high speed trains.
Conventional Acela Express trains have to run slower than its capacity, because North East Corridor is so busy that those trains cannot run rapider.