THE USER REQUIREMENTS STUDY WAS DIVIDED INTO TWO PHASES: (1) PAST TRENDS IN EXISTING DATA TYPES WERE STUDIED TO PROJECT FUTURE TRENDS IN COMMUNICATIONS TRAFFIC FOR THESE DATA TYPES; AND (2) NEW DATA TYPES THAT DO NOT YET EXIST BUT WHICH ARE ANTICIPATED WERE STUDIED SO AS TO ESTIMATE THEIR FUTURE TRAFFIC VOLUME. A SURVEY OF 48 STATES' INTERESTS AND NEEDS WAS CONDUCTED BEFORE TWO STATES WERE SELECTED AS EXAMPLES OF THE TRAFFIC PREDICTION AND NETWORK DESIGN PROCESSES. USERS IN THE MODEL STATES, OPERATORS OF THE MODEL STATES' EXISTING CRIMINAL JUSTICE COMMUNICATIONS SYSTEMS, AND OFFICIALS OF THE STATES' PLANNING AGENCIES WERE SURVEYED AND INTERVIEWED TO OBTAIN THEIR VIEWS ON FUTURE COMMUNICATIONS NEEDS IN THE MODEL STATES. USING TRAFFIC GROWTH MODELS FOR EXISTING AND NEW DATA TYPES, PREDICTIONS OF TOTAL CRIMINAL JUSTICE COMMUNICATIONS SYSTEM TRAFFIC WERE GENERATED FOR EACH OF THE MODEL STATES FOR 1977 THROUGH 1985. THE ANALYSIS SUGGESTS THAT NEW DATA TRAFFIC IN OHIO WILL INCREASE FROM AN EARLY 1977 VALUE OF ABOUT 14,000 MESSAGES PER DAY TO 170,000 MESSAGES PER DAY IN 1985. IN TEXAS, THE INCREASE WILL BE FROM A 1977 LEVEL OF ABOUT 9,000 MESSAGES PER DAY TO 90,000 IN 1985. THE GROWTH IN TEXAS IS LOWER BECAUSE OF THE USE OF LOCAL OR REGIONAL DATA BASES INSTEAD OF THE STATE FILES. IF DATA TRAFFIC CONTINUES TO INCREASE AS IT HAS IN THE PAST, AND IF NEW DATA TYPES ARE IMPLEMENTED AT THE RATE STATE PLANNERS PREDICT THEY WILL BE, STATE COMMUNICATION SYSTEM OPERATORS AND DATA SYSTEM PLANNERS SHOULD PREPARE FOR A CONTINUING PROGRAM OF UPGRADES TO TERMINALS, LINES, SWITCHERS, AND CENTRAL PROCESSORS. THE NEED FOR SUCH PLANNING IS APPARENT IN THE TWO MODEL STATES, AND MANY OTHER STATES ARE LIKELY TO EXPERIENCE SIMILAR GROWTH. THE APPENDIXES CONTAIN THE INSTRUMENTS USED IN GATHERING DATA, AND REFERENCES AND A BIBLIOGRAPHY ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--RCB)