Chun-Kai (Karl) Huang et al. have self-archived "Access to Academic Libraries: An Indicator of Openness?"
Here's an excerpt:
Results. Academic library policies may suggest open public access but multi-layered user categories, privileges and fees charged can inhibit access, with disparities in openness emerging between library policies and institutional open access policies. Conclusion. As open access publishing options and mandates expand, physical entry and access to print and electronic resources in academic libraries is contracting. This conflicts with global library and information commitments to open access to knowledge.