TRENTON, N.J. (September 24, 2012)—Amtrak announced Monday it will operate test trains overnight at 165 miles per hour in four stretches from Maryland to Massachusetts using Acela Express equipment.

All the locations may one day have regular 160 mile-per-hour service and Amtrak says tests need to be performed at 5 miles per hour faster than what is expected to be a maximum operating speed of 160 mph.

Two test locations from Perryville, Md., to Wilmington, Del., and from Trenton to New Brunswick, N.J. currently have speed limits of 135 miles per hour while the other two, in Rhode Island from Westerly to Cranston and in Massachusetts from South Attleboro to Readville, have 150 mile-per-hour limits.