Daniels and Sheppard were struck and killed by a train operated by a BART management employee who was being trained as an operator as BART went through its second strike of the year. BART has since eliminated the simple approval procedure, which was also in use when another BART employee was killed by a train in 2008.

Sal Cruz, a veteran train controller at BART, said "it's going to be a long process" for the transit system to implement the NTSB's recommendations. At the same time, he said both managers and workers at the agency have "known for quite some time that these recommendations were coming down the pipeline" and are already studying new safety systems.

Cruz said a committee made up of both management and union representatives are evaluating safety systems. "We’re hoping in the next few months for BART to adopt one of these technologies," he said.

The NTSB letter to the Federal Transit Administration:

Alex Emslie of KQED News contributed to this post.

simple approvalsimple approval

NTSB Urges Safety Upgrades in Wake of BART Worker Deaths