It’s been so long since Metro used computers to drive its trains that its operators lack expertise in how to use the technology and the agency doesn’t know whether automatic trains can comply with new procedures it imposed to protect workers on the tracks, according to agency officials and safety audits.
The transit agency has hired the engineering consulting firm Mott MacDonald — at a cost of just over $1 million — to study the potential safety impact of restoring Automatic Train Operation (ATO), which for riders would mean smoother rides, precise train positioning at platforms and fewer time-wasting stops and starts.
“ATO has advantages. It takes the human error out of train operations in many cases, provided you have a vital system that’s working right. And it can give you more capacity in the tunnel,” said Metro board member Robert C. Lauby, who also is chief safety officer at the Federal Railroad Administration. “But certainly if the system that’s in place is not capable of providing a higher level of safety, then it’s probably not a good idea. It will come down to the question of, ‘Is the current system able to take care of all the functionalities that are out there that need to be handled in 2018?’ ”
The study is due this summer, the agency said.
Metro was designed for computer-driven trains, and that’s what was used until the 2009 Red Line crash near Fort Totten. Eight passengers and the train operator were killed when a computer-driven train slammed into the back of a stationary one at an estimated 49 mph, at the height of the evening rush. It remains the deadliest crash in Metro history.
Automatic Train Operation was suspended indefinitely following the crash.
The ATO system itself was not at fault in the crash, however, federal investigators determined the issue was a faulty track circuit module. Metro’s signal system uses a network of electrical circuits that communicate the location of trains on the tracks. Faulty circuits can cause a train to “disappear.”
Metro spent $106 million to replace 1,700 track circuits in the system as part of a National Transportation Safety Board recommendation, with an eye toward eventually returning to automatic operation. ATO was restored to the Red Line briefly in spring 2015, with plans for it to be restored systemwide by 2017.
But the Red Line restoration was short-lived, and the systemwide transition never happened. After Paul J. Wiedefeld came on as general manager in 2015, he said ATO was not a priority because the agency was focused on initiatives critical to safety and maintenance. Metro said it ran limited automatic operations on the Red Line for about six months in 2015; the feature was limited to eight-car trains because at the time the computers were not programmed to position six-car trains at the end of station platforms. Metro discontinued ATO because when Wiedefeld and his team arrived, they focused on more pressing concerns and “for safety and consistency, all trains were moved back to manual,” the agency said.
Metro said the tens of millions of dollars in upgrades were critical for the safety of the system — even if automatic operation is never restored.
It is “important to keep in mind that the infrastructure improvements that have been made over the past several years mean a safer and more reliable signal system overall, in addition to removing any infrastructure barriers to a return to ATO,” Metro spokesman Dan Stessel said.
While smoother rides and stops would be a refreshing change for riders, officials say the system’s needs today are vastly different from when Metro opened in 1976, complicating their decision to return to automation. Parts of the 117-mile system are frequently turned into work zones, preventive maintenance efforts have cut operating hours, and service has been scaled back to meet scheduling expectations and reduce wear on the tracks.
Because of technical limitations, ATO is unable to comply with the 10 mph speed restriction the agency instituted for work zones following several potential accidents involving workers on tracks.
The ATO system needs to be “ ‘smart’ enough to know that the workers are present and enforce the applicable speed restriction,” Metro said. The current infrastructure isn’t capable of detecting workers who might be laboring on different segments of track and moving between work zones throughout the day.
Gus Ubaldi, a consultant and veteran railroad engineer who was involved in the design of the Metrorail system, said a workaround is available: using trackside overlay equipment that supplements the existing signal system and can be programmed to signal that workers are in an area.
“You can put a device in the track that will alert the train,” Ubaldi said. “Basically it’s a portable transmitter because obviously the workers are going to be moving from point to point. . . . It already exists.”
Another issue is time. Since ATO hasn’t been used across the system for nearly a decade, a significant number of Metro operators in all likelihood don’t know how to use it.
“Probably some of the operators have never used it and don’t know how it works, how they initiate it, how they monitor it,” Lauby said. “The same thing for the [Rail] Operations Control Center. That’s a major issue if you’re going to make a major change like this.”
Metro made the same conclusion in a 2017 report, noting that training, not engineering, would be an obstacle to restoring automatic train operation.
“The delay of ATO . . . is not an ATC Engineering problem,” Metro said in the report. It’s that the operators have to be trained, it said.
With ATO, computers do the driving — keeping the trains at the proper distance and speed. Operators open and close the train doors at stations and make announcements.
Metro declined to say how soon automated trains could return, saying any potential timeline is contingent on the consultant’s analysis. The agency also is not training any drivers on ATO.
“Any training would occur in advance of a return to ATO, if there is to be one,” Stessel said.
Despite the benefits, the technology is not a fail-safe. In winter 1996, the operator of a computer-driven train was killed when it slammed into an unoccupied train at 75 mph at the Shady Grove stop on the Red Line. Investigators found that Metro had decided to keep trains in automatic mode rather than switch to manual as a snowstorm hit the region, and they criticized the agency’s outsize faith in the capabilities of the computer system.
Metro’s “total faith in technology, no matter how advanced and sophisticated that technology may be, is inappropriate,” the safety board concluded.
Further, the NTSB said, Metro was so reliant on computers that train operators were inexperienced at operating trains manually.
Last year, top Metro officials hinted the agency was exploring a shift to the more modern Communications-Based Train Control system used by New York and other transit agencies. Stessel said those considerations are on hold.
“CBTC is a long-range discussion and is many years down the road,” he said. “We are focusing on answering the ATO questions first, and only then will we pivot to CBTC.”