The city was London, with 36 different wayfindng systems in the central area alone. The study found 4% of people using the wayfinding systems and 44% using the London Underground map for walking -- above ground!
Over the next ten years, they developed a "system" - not just guidelines - that would present a single way of doing things for its users - the pedestrians of London. In the process, they would "design the best way to impart complex information by using human geographic cognition, develop a legible language, and set up methods to allow the city's organizations to play their part."
Legible London has inspired other cities throughout the world. Read what the chief designer of the program, Tim Fendley, has to say about the future of navigation in smart cities and his six guidelines for continued progress. There are lessons to be learned for lesser projects!