It begins about 1/3 down this page: nextcity.org.
“For anyone passionate about the inner workings of our cities, the BART lab is nothing less than an urban planning wonderland. Inside a glassy skyscraper across the street from Lake Merritt, all types of machines and turnstiles coexist in varying states of disassembly. People like John Yen, BART’s acting manager for fare collection engineering, who offered to show me around, spend their days perfecting the technology that keeps the rest of us moving.”
“The walls are lined with BART ticket kiosks and other pieces of machinery from BART’s history, many with their faces removed or hanging agape to reveal their complex and compartmentalized inner workings.”