Connecting Boyle Heights and downtown Los Angeles, the First Street Viaduct was completed in 1929 and can be spotted by its classical-style keystone archways that extend over five pairs of square piers along the main deck of the bridge. Although retrofitted in 1996, the bridge was also part of a bigger construction project starting in 2007, when it was widened to make way for increasing west-bound traffic and to clear a path for the new MTA Gold Line light rail from downtown to Pasadena. The project is still in the works. When completed, the viaduct will be expanded by 26 feet, but still retain much of its original architecture and design.
Below is a video clip of the first street bridge, a historic piece of architecture found in downtown Los Angeles.