The Pursuit of Perfection
You probably don't realize it, but, at any given hour on any given day, a small yet incredibly sophisticated train armed with cameras, lasers, and ultrasound equipment is sliding around New York City's subway system inspecting the tracks. It looks a little bit like Optimus Prime, and, like the good Transformers, it's there to keep you safe.
KEEPING NEW YORK CITY SUBWAY SAFE
Inside, the track geometry car is like a giant computer, complete with a server and screens around every corner. The one that makes the most immediate sense to a layperson is situated just to the left of the driver. It shows the cross section of a rail and scan of the whole tunnel created by lasers and other instruments.