The operation of Chile University Bookmobile is taken from an article by M.L. Arenas written in 1973. the Bookmobile was operational in 1968. At that time, and as far as I know at this time as well, the University of Chile had departments widely spread around each with its own specialist library. the public libraries were poor, so students did not have much of a chance to develop cross curricula and broad reading skills. There was a need for a general library to be accessible to all the students, and the idea of using a bookmobile was developed. Parking space was sometimes a problem, which is always the case with a large van. They issued books, records (remember vinyl?) and music scores, and visual slides which were lent with a viewer. The items could be returned to any faculty library.
Unusually, borrowing required no registration, no special card, no overdue fines or membership suspension for defaulters. It made it very easy to use. Ease of use is a major factor in the success of a mobile library. If a customer is worried that they will not be able to return an item at the correct time, or they are likely to miss the visit, or they have to have some special membership, it is likely that they will not use the service at all. Few constraints and co-operation with local libraries is a good way to promote the mobile service, while getting people into the borrowing habit, and getting them into static libraries as well.