CONELDEN-FEA L CONCLUSIONS AND RECOMMENDATION CONCLUSIONS Feasibility 1. The feasibility of mass evacuation has not been proven by actual test in any large city. There are serious difficulties facing realistic practice on the necessary scale. Current survival plan projects in a numberof large cities may find ways of overcomingthe difficul- ties. 2. Mass evacuation of large cities to smaller villages and towns is not feasible within expected warning times of air attack. 3. Radial roads to permit the mass evacuation of major cities could not be built in time for this tactic to have any value. 4. The feasibility of an undergroundshelter construction program has not been proven to the point of stimulating Congress to provide public funds. The technical know-how for large shelter construction exists, although one of the most promising and inexpensive designs has not been tested. Effectiveness 5. In the Washington area, against attack with one to four 10-Mt ground-burst weapons all aimed at the population center with a 4000-m c#p, results were as follows: a. Use of undergroundshelter, evacuation with 1959 warning time, and evacuation with 1956 warning time are all more effective civil defense measures than use of existing shelter. b. Use of underground shelter and evacuation with 1959 warning time are more effective than evacuation with 1956 warning time. c. Use of undergroundshelter is moreeffective against several weapons than evacua- tion with 1959 warning time, andis as effective as such evacuation against a single weapon. 6. In the Boston area, against attack with 10-Mt ground-burst weapons simed at the population center, use of underground shelter is more effective than any othercivil defense measure for all weights of attack from one to four weapons andforall cep from 4000 to 12,000 m, even when effects of fallout are completely ignored; the superiority of underground shelter is further increased when fallout is considered. 7. In the Milwaukee and St. Louis areas, against attack with 10-Mt ground-burst weapons, wheneffects-of fallout are ignored, evacuation with 1959 warning timeis the most effective measure for a cep of 4000 m, and undergroundshelter is the most effective measure for a cEP of 12,000 m. When fallout is considered, the superiority of evacuation with 1959 warning time for a cep of 4000 m is reduced and perhapseliminated, depending on the local and regional fallout pattern, and the superiority of undergroundshelter for a cer of 12,000 m is further increased. 8. In the Dayton area, against attack with 10-Mt ground-burst weapons, when effects of fallout are ignored, evacuation with 1959 warning time is the most effective measure for ORO-—R-17 (App B) 87 itecSotLEA