THIS ARTICLE BASICALLY CORRECTS THE INACCURATE COST INFORMATION PRESENTED IN THE PREVIOUS REPORT. LABOR COSTS, ACCORDING TO THESE ESTIMATIONS, ACCOUNT FOR ABOUT 90 PERCENT OF THE TOTAL OPERATING COSTS, OR ABOUT $1.11 PER CAPITA. THIS FIGURE IS BASED ON THE ESTIMATE OF 1 SUPERVISOR TO 10 OPERATORS. THE NUMBER OF INCOMING TRUNKS IS NOT DIRECTLY PROPORTIONAL TO THE CITY'S POPULATION, BUT IT CAN BE SHOWN TO BE APPROXIMATELY LINEAR WITH THE POPULATION. THE NUMBER IS BASED ON A STATISTICAL FORMULA RELATING TRAFFIC, TRUNKS, AND GRADE OF SERVICE. EQUIPMENT ESTIMATES, BASED ON $175/MONTH/POSITION PLUS $450/POSITION FOR INSTALLATION WITH THE NUMBER OF POSITIONS EQUAL TO THE NUMBER OF OPERATORS REQUIRED IN THE BUSIEST HOUR ARE ABOUT $0.44 PER CAPITA PER YEAR. THE FACILITY COST, HOWEVER, IS AN ADDITIONAL $0.36 PER CAPITA PER YEAR. THUS THE TOTAL 911 SYSTEM CAN BE CALCULATED TO COST (EXCLUSIVE OF DIGITAL EQUIPMENT AND FACILITY)$1.18 PER CAPITA ANNUALLY PLUS 3.7 CENTS PER CAPITA, RELATIVELY INDEPENDENT OF POPULATION. MICROWAVE COSTS AND ERLANG'S FORMULA FOR ANALYZING 911 TRAFFIC ON A 'LOST-CALL' (ALL TRUNKS BUSY) ARE DISCUSSED. SEE NCJ 63024 FOR THE ORIGINAL REPORT. (MJM)