How Engineers Working Pro Bono Solved New York’s Toughest Subway Problem

It took just a few weeks for a small team of university engineers working pro bono to solve a problem that has vexed the nation’s largest transit agency and a global consulting firm for years.

In 26 days, starting Dec. 7 through New Year’s Day, six engineers from Columbia and Cornell universities developed a workaround to avoid the full shutdown of a busy section of New York City’s L-train subway line that has been planned—and dreaded—for more than two years.

In an interview Friday, the deans of the engineering schools said their solution drew on technology and ideas used in subways, bridges, tunnels and other infrastructure around the world. There was no eureka moment—just a succession of proposals that coalesced, said Mary Boyce, dean of Columbia University’s engineering school.