Chongqing, in southwestern China, is scheduled to open a station that is 309 feet underground by the end of 2017.
The project will connect the current Hongtudi station of Line 6, which is already 196 feet underground, with the new and much deeper Line 10.
Ninety-one escalators will be installed to transport passengers between Lines 6 and 10 and the surface.
It currently takes passengers 3 minutes and 15 seconds to enter or leave the Hongtudi station.
The alternative is a stairwell with 354 steps.
But…what if the elevator stops working?