My garage at work is a county garage. There are bikes (and a few have been removed) that have been here for YEARS. Literally. We old timers have watched the tires go flat and the bikes rust.
We frequently get summer interns and fellows working here. They have no money, get a cheap beater bike to use while they're here, and at the end of their assignment, move to parts unknown, leaving the bike behind.
Our bike team recently reclaimed 12 of 20 lockers which had been abandoned and started managing their use to keep them occupied by cyclists.