Powell Station death serves as a grim reminder. BART doors don’t stop for anyone

What you need to know about safety sensors on the trains

09/17/2021

SF Examiner

The death of San Francisco resident Amy Adams last week serves as a reminder: BART doors do not have motion sensors to keep them from closing when something’s in the way.

Adams, 41, had boarded a Dublin/Pleasanton train at the Powell Street station a little after 3 p.m. Sept. 13 with her dog, before exiting “at the very last second,” according to a BART press release. The doors closed with her dog on the train, its leash wrapped around Adams’ waist. When the BART train left, Adams was dragged onto the tracks and to her death.

It’s a horrific tragedy, raising many questions. Don’t BART doors have motion sensors that could have detected the presence of a leash caught between them? Shouldn’t there be a button by which passengers could reopen doors in an emergency?

According to BART spokesperson Jim Allison, however, there are no motion sensors because the potential for abuse outweighs the cost, however terrible that price may be. “One can only imagine trying to run the fifth busiest rail system in the United States, where we’re trying to keep things on schedule, with the doors closing and reopening constantly,” he says.

Details of what happened in Adams’ case are still under investigation by both BART and the National Transit Safety Board, so Allison couldn’t speak to the specific incident. But similar injuries have happened before. In February, a man suffered head and leg injuries after being stuck in BART doors, also at the Powell Station.

But Allison says that people who jam the doors with their bodies is a far more common problem. BART has been trying to address the issue for years, publishing communications on its website and podcasts. The Examiner asked BART more information about door incidents; the latest available numbers show that in June 2018 alone, 116 BART cars were delayed due to doors being jammed. In the 2017-18 fiscal year, so-called “door vandalism” delayed 816 trains, interrupting commutes for thousands of Bay Area residents. Often trains have to be halted completely, while mechanics work to get the doors back on their tracks.

It’s rare for train doors to have motion sensors, worldwide. One exception is Singapore, where citizens quickly began abusing the sensors by blocking them with chewing gum. It’s one of the main reasons the sticky substance was famously banned in the country in 1992. Singaporean statesman Lee Kuan Yew, who’s credited with both putting Singapore on the global financial map and creating a very strict and tidy culture, once scorned gum-chewing scofflaws publicly. “Putting chewing gum on our subway train doors so they don’t open, I don’t call that creativity,” he said. “I call that mischief-making.”

BART’s solution is to have physical triggers programmed into the doors that can tell when objects as large as three-fourths of an inch are in the way. These electrical and mechanical triggers, Allison says, are technically different from motion sensors used for elevator doors. Rather than sensing an obstruction before the doors close, these physical triggers detect whether or not the doors have already closed on something and are not fully sealed. When there is an obstacle in the way, an alert notifies the train operator in the control cab.

Aside from possibly clearer signs warning riders that the doors will close on people if they stand in the way, BART has few other tools available to increase safety on the trains. Allison says the fact that train operators are alerted when there’s something as small as three-fourths of an inch in the door is more conservative than what most transit experts would expect.

Of course, most dog leashes are thinner than three-fourths of an inch, and sensors did not save Adams’ life. That, according to a BART press release, is purely “tragic.”

SF Examiner: https://www.sfexaminer.com/news/powell-station-death-serves-as-a-grim-reminder-bart-doors-dont-stop-for-anyone/