Yanking Out The Underground Tracks Is One Way To Solve Urban Mobility Problems In London

The architecture firm’s “Walk the Line” concept subs in airport-esque people movers for Underground cars.

“Transportation in London is a bit of a minefield,” Christian Coop, design director at NBBJ’s outpost in the British capital, says. The global architecture firm is no stranger to wildly imaginative design proposals and when prompted to dream up a way to make the city better, NBBJ turned its attention to the Underground—a labyrinthine system that accommodates more than 1 billion passenger trips in a year and is notorious for congestion and overcrowding.


“The Tube is one of the oldest things in the city,” Coop says. “It is a great thing, but how do you make it better? We looked at a Tube station and how people move through it. From the surface to platform, the flow is good then you wait for a train and it builds up. You get trapped in the doors, it causes delays, and there’s a ripple effect for the entire line. We thought, it’s not about making people go faster, it’s about making the experience smoother.”

To improve mobility in the city, NBBJ suggests ripping out track on the Circle Line, one of the most heavily trafficked routes, and installing a network of moving walkways (like the ones you see in most airports). “Walk the Line” is divided into three zones, each with a different speed. Like lanes on the freeway, the paths become progressively faster as you move from right to left. In the stations, the rightmost walkway moves at three miles per hour—your average walking pace—the next one is six miles per hour and the fastest is nine miles per hour. As you hop between each one, your body only registers a 3 mph speed increase. In the tunnels, the speeds increase to six, nine, and 12 mph.

Without service delays—rare—it takes about an hour to complete the loop on the train line and the top speed is 20 mph; NBBJ estimates that the Walk the Line concept can make the journey up to ten percent faster. Moreover, you can walk along each one to make the trip faster and get your steps in for the day.

The initial inspiration for the design hearkens back to Thomas Edison moving sidewalk project for the 1900 Paris Exposition. “Typically, when you ask people about making the Tube better, they say you have to increase the frequency and you have to increase the amount of carriages,” Coop says. “If you follow that logic, you’ll get an infinite number of cars and then you essentially get a travelator.”

While the design feels far fetched, Coop points out that the the idea is grounded in technology that’s available today. “There are obviously massive technical hurdles but in many respects we’re talking about simple components and a concept that’s strong,” he argues. “What’s great is that what we’ve done is get people talking about ways to make the trains better and not just putting it up with how it is. I hope it sparks imagination about ways technology can impact commuting in the city.”

About the author

Diana Budds is a New York–based writer covering design and the built environment.