- The sign was not clear. Looking closer at the sign you see a lot of information. It is so much people probably don't know where to start reading. If this happens people will discard the complete sign. Sign with information overload
- Habit. Habits are difficult to kill. This probably applies to most Amsterdammers who came into the building expecting the postal office. They knew from their year long experience the postal office is there. They probably discarded the sign as advertisement or something else and just went straight for their goal.
- Pointed to the wrong direction. I noticed several tourist were brought to the location by taxi drivers. The taxi drivers didn't know it was moved. Without questioning the tourists followed directions and just walked in the building to discover the postal office was gone.
- Educate! Big Visible Charts are not enough. People must learn how to read these charts and act upon it. This especially goes for doing Agile projects in traditional environments. People in these settings are typically not used to get that much information in such short time.
- If it is outward-facing information (e.g. for stakeholders) then the readers need to be able to understand it in a couple of seconds. Don't use a lot of words, but use pictures or simple charts instead.
- If it is inward-facing information (e.g. for team members, product owner) then it can be fine-grained with details.
- You could try to physically separate the outward-facing information charts from the inward-facing information charts.
PS: After googling I also found some studies about successful (commercial) signs, for instance: https://web1.msue.msu.edu/imp/modtd/33719792.html. This also contains stuff like color schemes and such. Do you know more?