According to the Positive Train Control Enforcement and Implementation Act of 2015, which was signed into law on October 29 2015, the original statutory deadline for railways to complete the full implementation of PTC systems was extended from December 31 2015 to December 31 2018.

However, by December 31, USDOT says that only four railways - Southern California Regional Rail Authority (Metrolink), North County Transit District, Port Authority Trans-Hudson Railway (Path), and the Portland & Western Railroad - have completed the implementation of PTC. All trains on these networks, whether they are operated by the host or tenant railway, are now governed by a PTC system.

The remaining 41 railways had until December 31 to meet federal stipulations to receive a two-year deadline extension or “alternative schedule.”

The Class 1s make up seven of the 37 railways which requested up to a two-year deadline extension for PTC implementation from the Federal Railroad Administration (FRA), according to USDOT. They were joined by 25 inter-city and commuter railways and five shortline or regional railways.

Twelve railways have received conditional PTC system certification from the FRA, allowing these railways to operate PTC in revenue service. USDOT also reports that 66,000 route-km is now in PTC operation, meaning 71% of route-km subject to the mandate has met the federal goal. Around 29% of the route-km operated by the Class 1s is not yet covered by PTC.

In December, 11 projects to implement PTC systems were awarded more than $US 46m in FRA grants. The FRA also announced $US 203.7m in grants for PTC implementation to support 28 projects in 15 states in August 2018.