THE SUBJECT OF 911 HAS BECOME CONTROVERSIAL LARGELY BECAUSE OF MISUNDERSTANDING AND PAROCHIALISM. THE BASIC PROBLEM IS THAT RARELY DO TELEPHONE EXCHANGE BOUNDARIES AND POLITICAL SUBDIVISIONS COINCIDE. HENCE, EITHER MANY EXTRA DEDICATED TRUNK LINES ARE REQUIRED FOR EACH AGENCY INCLUDED IN THE TELEPHONE EXCHANGE, OR AGENCIES MUST REFER CALLS. THE RESULT IS THAT WHILE 911 HAS BEEN ESTABLISHED IN 340 LOCALITIES, IT STILL ONLY SERVES 12 PERCENT OF THE U.S. POPULATION. IN ADDITION, MISCONCEPTIONS CONCERNING 911 ABOUND. MANY PERSONS BELIEVE THAT 911 MEANS DELAY IN CALLS FOR FIRE EQUIPMENT, THAT 911 IS EXTREMELY COSTLY, AND THAT ITS USE WILL MEAN A LARGE INCREASE IN THE NUMBER OF CALLS DISPATCHERS MUST HANDLE. THE SEATTLE EXPERIENCE DISPROVED THESE ERRONEOUS ASSUMPTIONS. BASED ON SEATTLE'S EXPERIENCE, GENERAL GUIDELINES OF SYSTEMS COSTS AND CONFIGURATION HAVE BEEN IDENTIFIED. FIRST, THE CORRECT NUMBER OF OPERATORS MUST BE DETERMINED. A GOOD ESTIMATING FIGURE TO USE IS 2.5 CALLS PER 1,000 POPULATION PER DAY. EACH CALL AVERAGES 50 SECONDS, SO EACH OPERATOR CAN HANDLE BETWEEN 30 AND 60 CALLS PER HOUR. SECOND, THERE MUST BE OPERATOR POSITIONS SUFFICIENT FOR PEAK HOUR LOADING; SHIFT ANALYSIS IS THEREFORE REQUIRED. SIMILARLY, LABOR COST ANALYSIS IS REQUIRED IN TERMS OF MAN HOURS NECESSARY PER DAY. TRUNK COSTS DEPEND ON THE DISTANCES INVOLVED AND OTHER FACTORS, BUT $60 TO $90 PER MONTH IS A REASONABLE ESTIMATE. TELEPHONE TERMINAL AND OPERATOR EQUIPMENT CAN BE ESTIMATED AT $175/MONTH/POSITION PLUS $450/POSITION FOR INSTALLATION. FACILITY COSTS WILL VARY WIDELY BECAUSE EXISTING FACILITIES CAN OFTEN BE USED. IT IS DESIRABLE TO CONSIDER MICROWAVE BACKUP FOR ANY LARGE SCALE 911 SYSTEM. IN ADDITION, OPERATIONAL, HUMAN ENGINEERING, AND DIGITAL SYSTEMS FACTORS SHOULD BE CONSIDERED. THE MATTER OF CONSOLIDATION IS PERHAPS THE MOST CONTROVERSIAL OF ANY CONCEPT IN 911 PLANNING; CONSOLIDATION SHOULD DEPEND MAINLY ON TECHNICAL AND COST FACTORS, GEOGRAPHY AND LOGISTICS, AND ECONOMY. A 911 SYSTEM CAN BE IMPLEMENTED FOR A PER CAPITA COST OF 50 CENTS INITIALLY AND 65 CENTS A YEAR THEREAFTER, PROVIDED THE DECISION TO IMPLEMENT IS MADE NOW. FORMULAS AND A FOOTNOTE ARE INCLUDED IN THE ARTICLE. (LWM)