I play poker (with the appropriate face) once a month with a dentist, two psychologists and, two psychiatrists. One of the psycholgists reported a case of a patient who carpooled to work in San Francisco, but on the way to or from work had to go through a mile-long tunnel (the Caldecott tunnel). Everything with the commute went well, but in the tunnel the patient became agitated, and feared totally losing control in the tunnel. The patient had no problem driving through the tunnel when NOT in the carpool! The case had stumped the therapist, but one of the poker group had read about similar cases of this condition in the literature. The diagnosis was clear: carpool tunnel syndrome.