Information about and excerpts from the 1981 "Commuter Institution Index," an annual publication on research on commuter institutions of higher education are presented. The Index provides an overview of the demographic characteristics of responding institutions and the functions most frequently performed by these institutions for commuters. It includes statistical analyses of institutional type, size, control, and membership status in the National Clearinghouse for Commuter Programs. Tables also allow assessment of the services offered by specific institutions. Over 600 institutions were surveyed in 1981, including 200 community/junior colleges. Findings regarding the following are presented: the percentage of commuters in student populations, the percentage of part-time students, the percentage of students living 2-20 miles from campus, the percentage of all students living with parents, and general trends. Specific functions performed by institutions on behalf of commuting students are listed under the following broad categories: service function, program function, advocacy function, and research function. These functions include the following: orientation programs for commuters, off-campus facilities, counseling and tutorial programs geared to commuters, student voice in programming decisions, transportation for commuters, and research on commuters' needs. Excerpts from the "Functions Available by Institution" list are included. (SW)