Metro has been testing ATO for more than a year as it moves toward returning train operations to automatic piloting. Metrorail was designed for the ATO system and had been operating that way for decades until a fatal train crash 14 years ago. Train movements have since been controlled manually by operators in each train’s cab.
The train operating in ATO earlier this month shot past the Innovation Center station platform, said Max Smith, spokesman for the safety commission. During its ongoing investigation, the commission discovered the operator had used the ATO system multiple times, even though the commission hasn’t given the transit agency permission for its use.
“The evidence does show that this operator had been using it over the course of that day and had previously used ATO,” Smith said.
Officials are working to determine if the self-driving function has been used by other operators while carrying passengers.
“In the course of our review of other data, there are indications of certain other trains maybe having operated in ATO, but we also have to work to cross-check that data,” Smith said. “It’s possible at least some of those are false indications.”
Metro spokeswoman Kristie Swink Benson said in a statement that the operator admitted to using ATO, knowing it wasn’t allowed.
“When he was interviewed, he admitted he was curious to see if ATO would work,” Benson said. “Based on the investigation, there is no evidence this is a systemic problem.”
The relaunch of ATO this year will come after multiple attempts to bring the system back after a 2009 crash, when a Metro train operating in ATO rammed into a parked train near the Fort Totten station in Northeast Washington, killing nine people and injuring 80. Metro officials suspended ATO usage to sort out what had caused the rail system failure.
Multiple investigations found that the ATO system was not culpable in the crash. A separate train detection system that keeps trains safely spaced apart was found to be using flawed parts that prevented the system from sensing the parked train. Although Metro said ATO was cleared in the investigations, transit leaders at the time left Metrorail in manual mode, which became the default method of steering trains until a systemwide conversion in December this year.
A return to ATO, Metro officials say, will boost performance and safety by creating smoother rides while reducing opportunities for human error. Most large rail systems across the country already use automation, and Metro officials say ATO is needed to continue modernizing operations and to lure back riders after the pandemic.
The use of ATO requires the permission of the safety commission, an agency Congress created 6 years ago to monitor Metrorail safety. Commissioners this month expressed concern about whether Metro was prepared for the launch and whether transit leaders were moving too quickly.
The incident earlier this month underlined those concerns. Station overruns — when trains go past the spot where they should stop at station platforms — were a recurring safety issue when ATO was previously in use, Smith said.
“That’s one of the hazards that we’ve been raising to Metro to make sure is addressed and properly mitigated,” he said. “It’s not supposed to happen, but it happens and has happened before.”
Such incidents are a safety hazard for track workers who might be nearby. Smith said the safety commission alerted Metro General Manager Randy Clarke and top managers about the improper ATO use.
Benson said the overrun occurred at a station where a team that is testing and preparing Metro for ATO had not yet installed the necessary track equipment that interacts with the ATO system, and also had not conducted engineering tests.
As part of the ATO safety certification Metro needs from the commission, transit officials will have to show regulators how they are preventing overruns. They will also demonstrate what operators would do if a train went past a platform, Smith said. Operators will continue to ride in train cabs to monitor ATO functions, watch for track hazards and take over the train, if needed, after the system conversion.
Metro also needs to show the commission new protocols for keeping track workers safe under ATO. Current safety guidelines rely on communications and shared information between operators, rail operations controllers and, sometimes, flagmen posted on station platforms ahead of a work zone.
The operator who admitted to using ATO earlier this month was suspended pending an internal investigation, Benson said.
The transit agency issued a memo marked as “high” importance to employees after the incident, requiring supervisors to remind operators that “ATO Operation is strictly prohibited unless authorized testing is in [effect].”
The memo instructs rail traffic controllers how to spot signs a train might be operating in ATO. If they determine a train is operating in the self-piloting mode, the memo said, they should instruct operators to immediately switch to manual mode and notify managers.
Benson said operators also were given in-person briefings to remind them not to use ATO. Metro’s Rail Operations Control Center has increased system monitoring to check on the functions trains are using, she said.
