These kinds of signs are commonplace while work is in progress. But after the building is up, street is fixed, school is updated, etc., the link back to proposition, amendment, or tax increase that funded the work is lost. I think this eventually leads people to question why they are paying such high rates and fees. Even though their everyday environment is constructed through a series of taxpayer-sponsored improvements, they don't see direct evidence of it.
So how about an AR app that shows a rendering of how something would have looked if it were not for public goods? This could be extended to other improvements that are less visible. For example, an app could point out reductions in particulate matter in the air or water, reductions in crime in an area that is linked to housing or health initiatives, or even reminders of why something hasn't been fixed. This could also be useful to remind folks about the extensive government funding behind everyday devices.