The time needed to install and test a new GPS-related safety technology, positive train control, is the reason for the longer-than-expected implementation, officials say.

Richard Harnish, executive director of the private Midwest High Speed Rail Association, called the delays “really, really aggravating.”

“When other countries are going 220 mph over thousands of miles, the fact that we can’t get to 110 is really frustrating,” he said.

Positive train control helps monitor trains’ position and speed. Among other things, should a train engineer fail to respond to an upcoming signal, the train will take over controls itself and slow or stop a train to avoid a crash.

Marc Magliari, a spokesman for Amtrak, said there’s no assurance that the 90 mph speeds will happen on part of the route even by the end of the year.

He said it all depends on the outcome of testing at speeds of 90 mph expected to begin by the end of the year.

“We have to test it and the FRA looks at our test data,” he said, referring to the Federal Railroad Administration.