WASHINGTON -- The NJ Transit train that crashed into the Hoboken Terminal was traveling at 21 mph -- more than twice the speed limit -- before it went past the bumping post at the end of the track, the National Transportation Safety Board reported Thursday.

The commuter train accelerated from 8 mph about 38 seconds before the crash, which killed one person and injured more than 100 others. The throttle had been in the idle position but moved to a No. 4 position as the train accelerated. Just before the crash, the throttle returned to the idle position and the engineer tried emergency braking procedures.

The speed limit is 10 mph in the area. The information was gathered from event data and video recorders recovered from the commuter train.

The safety board said that the investigation into the cause of the crash could take more than a year. Technical experts and those involved in the investigation are scheduled to meet Tuesday at safety board headquarters in Washington to review the data from the recorders.

Among the issues to be looked at is the absence of an automatic speed control system on the tracks. Such a system could automatically have slowed down the train.

Such a system was supposed to be in place on all railroads by Dec. 31, 2015, but Congress voted to extend the deadline by three years. In its most recent report to the Federal Railroad Administration, NJ Transit reported no progress in meeting the timetable.

The absence of an automatic speed system contributed to a Mother's Day crash of an commuter train at the same Hoboken station in 2011, according to the safety board.

The safety board earlier this year said the absence of such a system contributed to the 2015 fatal derailment of an Amtrak passenger train on a curve in Philadelphia.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook