It was to be a little aesthetic touch added to the Eastside extension of the Gold Line as it neared completion.
But no one imagined what gremlins would be unleashed when workers added a layer of paint to the concrete at "cross-over" points where the light-rail trains could switch tracks.
The coloring agent was made of iron oxide. And at intersections like 1st and Clarence streets in Boyle Heights it caused the painted concrete to conduct an electrical circuit that basically told a lie.
"It was sending out a false signal that the train was there," said Dennis Mori, the Gold Line Eastside extension's project manager. "When the weather got hot, it did it more. . . . When we removed the painted concrete, the false signal disappeared."
As the Metropolitan Transportation Authority works to replace the painted concrete, the glitch is just one reminder of the challenges faced in completing the county light-rail system's first leg into the Eastside. For a while, officials estimated that the six-mile line could open sometime in the summer, maybe as early as June.
Now they are hoping for a November opening. That will still give the MTA enough time to do testing and open the extension before the year is over, and a federal funding deadline arrives.
On the surface, it looks as if there's quite a lot of work to do. On a stretch of the line along 3rd Street in East L.A., bulldozers and cranes excavate asphalt, and stretches of track lie exposed after the colored concrete was removed. Workers shovel in asphalt, which will be painted, but without conducting false signals.
There are shallow trenches along the side of the track. But Mori said most of the work that remains is finishing touches, and testing.
"We're 99% done with construction," Mori said.
The roughly $890-million Gold Line extension, which runs from Union Station to Atlantic Boulevard, has 1.7 miles of twin tunnels and two underground stations. But the bulk of it runs down the center of comparatively narrow streets, leaving not much separation between the line and vehicles passing by.
In contrast, much of the Pasadena-to-downtown L.A. portion of the Gold Line was built along train right of ways, Mori said.
For the Eastside extension, a vigorous safety campaign has begun, including citing people who jaywalk across tracks.
