CONENTAAL ration in allocating sectors of territory around Washington to federal agencies for their continuity-of-governmentactivities. The kinds and general quantities of minor basic employmentand secondary or support- ing economic activities around suburban nuclei and in the central city should be estimated. These generalized data are needed for broad design decisions in the fields of water supply, sewerage, highway capacity, and areas of land to be devoted to various uses. A study should be made of methods of preventing excessive concentration of those essential activities planned for long-time retention in the central area. Some shifts to more satisfactory sites or buildings are likely to occur over the years even among permanent intown activities. For example, in Washington the crater areas of weapons in the single megaton range are so great in relation to the Mall, the Federal Triangle, and the Federal Rectangle that some moves outside this core into other parts of the District of Columbia would be advisable. The Bureau of Standards’ current site, which will become available when the Bureau moves, would be safer for an important agency than a new building downtown, and an underground shelter there might survive a weapon that cratered out all shelters in the downtown area. Shelter needs should be calculated on the basis of planned ultimate redistribution of primary and secondary activities of the metropolitan area. The results of this study should be used in the search for suitable sites for underground shelters. There should be some opening up of land in the central area due to departure of less essential activities, which should reduce costs of land acquisition for the shelter program. Shelter construction priorities should also be studied. If a massive program were undertaken, someshelters would probably be built in all three zones immediately — central area, suburban nuclei, and intermediate zone. Local priorities would probably be related to importance of persons and activities to a war effort. Key Plans for Dispersal Theseries of staff studies recommended here should produce material from which offcial plans can be prepared. These plans would be similar to presently used comprehensive or master plans but would be based on an expanded distancescale. A plan for land use should be established to distinguish between open and close development throughout the dispersed development district. Close development areas should be subdivided into industrial, commercial, and residential areas, with residential further subdivided into principal density categories. For nonmilitary defense purposes a population distribution plan should be set up for both daytime and nighttimedistribution. Nighttime distribution should be a restatement of data on use of residential land, with the data converted to population figures. Daytime distribution should reflect intensity of development planned in industrial and commercial areas, plus residual nonworking population in residential areas. The backbone of a transportation plan will be a metropolitan system of freeways, composed of existing and proposed routes, extending throughout the dispersed development district. Routes included in the national system of interstate highways will usually form the framework on which freeway spurs and circumferentials reaching the suburban nuclei can be hung. Helicopter routes and major uncontrolled-access highways will probably also be shown. Commuter rail service may survive in some metropolitan areas. A water supply plan should be drawn up to show impounding, transmission, treatment, storage, and major distribution facilities for the various water-supply systems in the dis- persed development district. A sewerage plan is also needed, to show service areas, interceptor and trunk lines, and sewage treatment facilities throughout the dispersed development district. ORO-R-17 (App B) 88 “CONFIDENTIAL