DALLAS — Amtrak passenger service that runs on tracks owned by freight rail companies may be curtailed unless Congress extends a Dec. 31 deadline to implement a safety system that was mandated seven years ago, according to an Omaha World-Herald report.

December 2018 would be “more realistic” for implementing the technology, which automatically stops trains to prevent a collision or unsafe speeds, the Association of American Railroads said Tuesday in a statement. Only about a third of Amtrak’s 31.6 million passengers in fiscal 2013 traveled on its own tracks, so the majority may be affected if the freight railroads curtail or stop services, the report said.

The railroads face fines and penalties if the system isn’t operating by the end of the year. The Senate voted in July for an extension that requires having positive train control operational by no later than the end of 2018 in a transportation bill that needs approval from the House. For the full story, click here.