The Exposition Line train after finishing a test run.
Inspections have been ordered for the Expo Line / Blue Line rail junction because of a design issue that poses an increased risk of derailments, say state safety regulators.
Metro officials, however, say small modifications at Washington Boulevard and Flower Street have made a huge difference, and that the intersection is safe.
The issues in question stem from "non-standard" fixes, and a special inspection program is required, says Michelle Cooke of the California Public Utilities Commission's rail safety unit, notes the L.A. Times.
The extra inspections, which will continue indefinitely, were a condition of commission approvals to open the first 7.9 miles of Expo Line last month.
MTA records show the junction as built is defective and presents potential maintenance and safety issues, including a heightened risk that southbound Blue Line trains could derail in the sharply curving intersection — or elsewhere along their route — because of equipment damage.
About 140 trains trips a day are made on the Blue Line, one of the nation's busiest light rail systems with 26 million riders annually.
The tight turn of the junction track does not conform to recommended industry standards, and the design has never before been approved for MTA's passenger rail operations, reports the Times.
MTA officials initially pushed for Expo Line's independent construction authority to replace the junction in 2010 because of unusual wear, but settled on less expensive modifications.
"We believe we've solved the safety issues," said Vijay Khawani, the MTA's executive officer of corporate safety. "If we see trends that are negative, we will notify the Public Utilities Commission and identify a plan to address those problems."
The track manufacturer, Nortrak, does not approve of the modifications. Officials recommend a redesign and rebuild for the junction and said they will elaborate at a later time.