PORTLAND (AP) — A safety system that could have prevented the deadly Amtrak derailment in Philadelphia is not installed on Amtrak’s Downeaster service route because it does not meet traffic requirements.

The Portland Herald reported (http://bit.ly/1IC3UaB ) the positive train control technology is designed to prevent the human errors behind nearly 40 percent of train accidents. The system gives engineers and dispatchers real-time information about train speed and location.

Patricia Quinn from the Northern New England Passenger Rail Authority says there are no plans to install the system in Maine and New Hampshire because the number of passenger trains on the line falls below a mandatory minimum.

Quinn says the Downeaster has to offer two more daily trips to qualify for the system. The technology is already in other parts of the Northeast Corridor.