Thanks to a tip from Mark M., we learned that SFMTA today restarted its practice of double-stopping train cars in the Civic Center, Powell and Montgomery stations, allowing two trains to stop and open doors on the same platform at the same time.

SFMTA spokesperson Paul Rose told us via email today that double-stopping will be tested during morning and afternoon commutes today at the three stations. He continued: "This is a new rider convenience tool that manages congestion in the subway and ensures that riders don't have to wait for a train to clear the subway before exiting their vehicle. At these stations, the first train will stop further down the platform (closer to the end of the platform)."

SFMTA had worked for years on the program and initially launched it on May 24th, 2015, but quickly stopped it because a software bug prevented the system from triggering proper notices of incoming vehicles. We asked about its status in December of 2015, and were told more than a half-million lines of code had to be individually reviewed, and the agency wasn't sure of a restart date.

Rose told us, "These tests will ensure the system works properly, which includes testing for the previous issues." He also noted:

In the event of subway congestion, the first train will pull all the way to the far end of the platform. A second train, if in close proximity, will stop at the other end of the platform and open doors to let passengers off there as well. When the second train off loads passengers, the doors will close and eventually pull up to the front stopping position and open the doors again to allow passengers to board.

It is important to remember that the train, regardless of congestion, will always pull up to the front stop every time to allow passengers to board.