Thomas Ward

BART runs under Market Street in San Francisco, crossing the Embarcadero at almost a right angle, near the Embarcadero Station, at the west end of the Transbay Tube. The BART tunnel along Market was built in the Dark Ages Before Tunnel Boring Machines, using the old "cut and cover" method. It's difficult to imagine, today, cutting big holes in the middle of a major city arterial, disrupting traffic for years. There's your Civil Engineering History Lesson for today.