Washington restores ATO on metro network

The Washington metro, one of the first modern rapid transit systems in the United States when it opened in 1976, is now operating as designed.

WMATA has now restored ATO on its entire metro network.

Photo Credit: Shutterstock/Nicole Glass Photography

WASHINGTON Metropolitan Area Transit Authority (WMATA) has restored operator-assisted ATO to its entire 208km six-line metro network 16 years after it was suspended following a fatal rear-end collision on the Red Line.

Systemwide ATO comes six months after the Red Line returned to ATO on December 15 2024. WMATA switched to ATO on the Blue, Orange and Silver lines on June 15 and the Yellow and Green Lines followed on May 23.

WMATA says ATO was reintroduced following rigorous internal training and testing and approval from the Washington Metrorail Safety Commission. However, ATO is not used during poor weather conditions, single-track operation, and when workers are on the tracks.

The reintroduction of ATO has enabled WMATA to return to its original line speed of up to 120km/h. Several outer portions of the Blue, Orange and Silver lines will see speed increases from 88.5km/h to 105 or 120k/h in some stretches. On June 22, WMATA will reduce end-to-end travel times by about 3 minutes on these three lines while journey times on the Yellow and Green lines will be cut by 1-2 minutes.

“Based on analysis of several months of successful ATO operation in passenger service, end-to-end Red Line travel times have been reduced by a total of 8 minutes,” says WMATA.

Accident report

The fatal 2009 accident, which killed nine people including the driver of the following train, occurred because of a “loss of train detection in the automatic train control (ATC) system,” according to the National Transportation Safety Board (NTSB) accident report. ATC, with automatic train protection (ATP) and automatic train supervision (ATS), are ATO’s three subsystems.

“At the time of this accident, the ATC system was reporting [a track circuit] as vacant (unoccupied) even while it was occupied by train 214,” NTSB explained. “Based on that report, the system transmitted speed commands of 88.5km/h to train 112, which caused the train to automatically start and begin to accelerate to that speed. The ATC system transmitted speed commands of 88.5km/h to train 112 even as the train struck the rear of train 214.”