California Code, Vehicle Code - VEH § 12804.8

(a) Notwithstanding any other provision of law, the department may conduct studies to develop and identify examinations and tests, to more accurately identify persons who, due to physical or mental factors, or both, are not competent or qualified to safely operate a motor vehicle.

(b) In addition to any other tests or examinations required under this code, the department may require any person applying for an original driver's license or renewal of a driver's license, or any person subject to reexamination under Section 13801, to submit to one or more tests or examinations which are part of a study.

(c) The results and information obtained during the study, through the tests and examinations specified in subdivision (a), shall be used only to assess and evaluate the effectiveness of the tests and examinations and to select tests and examinations for use by the department, and for no other purpose.  The results of the tests are confidential and shall not be disclosed to any person.

(d) No public entity or employee shall be liable for any loss, detriment, or injury resulting directly or indirectly from the department's acts or failure to act on information received through the studies.