By Mike Baker / The Seattle Times

SEATTLE — Washington transportation officials won’t restart passenger service along the rail line where an Amtrak train derailed until advanced safety systems are in place, a spokeswoman said Thursday.

Barbara LaBoe, a spokeswoman for the Washington state Department of Transportation, said passenger trains will use the older rail line along the coast until “positive train control” technology is ready for the Point Defiance Bypass route.

The Amtrak train that derailed on Monday, killing three people and injuring dozens more, was on its inaugural passenger run along the new bypass line that was to speed service south of Tacoma. Investigators still examining the cause of the crash say the train was traveling 80 mph when it entered a curve that has a speed limit of 30 mph.

Positive train control systems can detect a train that’s exceeding speed limits and slow the train. Crews have been working to set up those systems on the Point Defiance Bypass route — and had hoped to have it ready at the start of service — but were still in the testing phase this week.

Officials had been working on an “aggressive” timeline to finish the new line this year, with documents showing the state had a deadline of the middle of the year to finish construction in order to fully collect on federal stimulus money awarded years earlier. The state had also vowed to open service in the fall.

LaBoe said the decision to halt passenger service on the new route until the systems were in place was not an indication that the state considers the tracks unsafe. She said the new line had been thoroughly inspected and that it was a matter of sensitivity, for those killed in the tragedy and for those who will ride the route in the future. She also said officials were wanting to have renewed conversations with communities along the new route.

“It’s not a question of the safety of those tracks,” LaBoe said. The older route where trains will continue running also does not have the train-control technology, but LaBoe said the state has been operating there for many years without major issues.

LaBoe said the state didn’t know when the train-control systems would be ready for the new line. A spokesman for Sound Transit, which owns the tracks, has said it’s planning to activate the technology before the end of June. Sound Transit has also been working to get more train-control coverage for its Sounder trains.

The National Transportation Safety Board, which is investigating this week’s derailment, has long pushed for train-control systems, repeatedly citing the issue after deadly crashes. In 2008, Congress mandated that railroads use the computerized systems by the end of 2015. But, facing cost and implementation challenges, the industry convinced Congress to extend the deadline until the end of 2018.

Accidents have continued to draw attention to the issue, and some have had speed similarities similar to Monday’s crash. In 2013, a Metro-North passenger train in New York derailed while traveling 82 mph at a curve where the maximum authorized speed was 30 mph, according to the NTSB, killing four people and injuring dozens. In 2015, an Amtrak passenger train in Philadelphia derailed while traveling 106 mph around a curve where the speed was restricted to 50 mph, according to the NTSB, killing eight people and injuring many more.

Earlier this year near Steilacoom, Pierce County, an Amtrak train derailed. Officials blamed speed and human error in that non-fatal accident, saying the engineer approached a drawbridge above the 40 mph speed limit.

That accident occurred on the older route where trains will continue traveling.