CONFED-EN-TEAE- POSSIBLE CIVIL DEFENSE ACTIONS AND FEASIBILITY Opposing the enemy attack are a variety of civil defense actions cities can take. These may be broadly categorized as changing the population configuration or changing the population vulnerability or combinations of these. The population configuration can be changed by mass evacuation of the city as a whole from some assumed aiming point to beyond the assumed lethal radius of a thermonuclear weapon; evacuation of the congested core of the city (partial evacuation); selective evacuation of the aged, infirm, children, etc., prior to warning of actual attack; or reduction of population vulnerability through long-range dispersal programs. The population vulnerability may be changed by a policy of seeking the best shelter now available in the target; seeking shelter in public or private underground shelters; preparing improvised shelter; designing and constructing blast-resistant buildings; or constructing undergroundinstallations. A combination of these two methods maycall for mass evacuation of the city to public shelters in the periphery; evacuation of the congested core of the city to shelter elsewhere within the target; or evacuation of the city population to smaller towns and villages. In this study the alternatives of mass radial evacuation, seeking the best shelter now available, seeking underground shelter, and seeking shelter in surrounding towns and villages are considered. Dispersal programs, blast-resistant designs, and underground installations are treated separately in Annex B of this appendix. MASS EVACUATION Determining Feasibility Ideally the feasibility of evacuating large urban targets could be determined by practice evacuations. Although there have been practice evacuations of somecities, such as Spokane,® Mobile,® Erie, Pa.,! and Portland, Ore.,!! the results have had little bearing on the problem of the feasibility of this tactic. In every case a relatively small portion of the target was evacuated, and in every case a relatively small proportion of the population in the evacuated area participated in the exercise. It may be reasonable to conclude that those persons who did choose to participate represent the population that would create the fewest problems in evacuation; perhaps those who did not participate were the aged, infirm, mothers with small children, and noncooperative persons, who might create special problems. In any event, in the tests conducted so far the size of the areas being evacuated has been too small and the numberof participants too few to permit any conclusions regarding the feasibility of this civil defense maneuver. in the absence of valid experiential data, an evacuation model was designed, based on the assumption that the numberoftraffic lanes leading out of the target would be a prime ORO-—R-17 (App B) SoaL ee Oe Ce ee pr aroraes 21 Parmesanthe UP er yap a ne