Metro is still years away from returning to running its trains automatically, instead of manually, in the ongoing aftermath of the deadly 2009 train crash.

The transit agency first has to finish overhauling its automatic train control system, a safety network that keeps trains from crashing into each other, the agency said Thursday.

While replacing parts, Metro has been analyzing and making its safety network more robust. Metro also plans to bring in an outside consultant to review its safety systems to make sure the agency isn't missing anything with its own analysis, the agency told its board of directors Thursday.

Only then, General Manager Richard Sarles told The Washington Examiner, will he feel comfortable looking at returning trains to automatic operations. He has repeatedly declined to give any timeline.

Running trains automatically is how the Metrorail system was designed to operate. The trains accelerate and slow down based on commands communicated electronically from the tracks to the trains. Riders get a smoother ride, and trains are less prone to back up as trains run more efficiently.

But the transit agency ordered all trains to be run manually after the 2009 Fort Totten train crash, when a train running automatically at full speed slammed into a stopped train. The train control system failed to show the stopped train on the tracks due to flawed signals. The operator threw the emergency brake when the train came around a curve, but it was too late. Nine riders were killed and another 80 were injured.

Since then, Metro has been undertaking what it says is a $70 million project to overhaul the safety system. The system, called automatic train control, is intended to space trains apart so they don't get too close. It sends alarms if trains go too fast in certain areas and can even slow down trains, bringing them to a stop as needed. When failures happen, it is supposed to be failsafe, meaning trains stop moving.

In September, Metro said it cleared a "significant step" in its quest to resume running trains automatically, when the National Transportation Safety Board approved a tool that Metro created to monitor the train system in real time to prevent trains from crashing. Since then, transit agencies from around the world have been contacting the agency to see how it works, according to the agency.

But Metro Deputy General Manager Dave Kubicek said Thursday it will take another two or three years to finish installing all 2,300 track circuit modules throughout the system as crews cannot do them while trains are running. The agency is still finishing the replacement of modules on the Red Line, then will need to finish the remaining lines.