DUPONT, Wash. (AP) — The railroad industry has installed safety technology on nearly 90% of tracks where it is required, but federal officials say “significant work” is needed to ensure the work is completed by a December 2020 deadline.

The industry expects to spend nearly $15 billion implementing the technology on Amtrak and freight and commuter railroads throughout the country.

Congress passed a law in 2008 to implement these safety features by 2015, but had to give the railways extensions to get the work done.

The National Transportation Safety Board says there have been 22 rail accidents since 2008 that could have been prevented by the technology.

This includes the December 2017 derailment of an Amtrak passenger train near DuPont that killed three passengers and injured 57 people, sparking renewed criticism that the technology was not in place.