Florian Brauner addresses the risk reduction effects of security measures (SecMe) as well as economic and social effects using terrorist threats in public transportation as use case. SecMe increase the level of security but cause interferences and restrictions for customers (e.g. privacy). This study identifies the interferences and analyzes the acceptance with an empirical survey of customers. A composite indicator for the acceptance of different SecMe is developed and integrated into a risk management framework for multi-criteria decision analysis achieving the right balance of risk reduction, costs, and social acceptance. Contents Assessment of Security Measures for Risk Management Measurement of Objective Effectiveness of Security Measures Against Terrorist Attacks Determination of Subjective Effects of Security Measures (Customer Acceptance Analysis) Cost Analysis of Security Measures Multi-Criteria Decision Support Systems Target Groups Scientists with Interest in Civil Security Research Providers and Security Experts of Critical Infrastructures and Companies Risk Management Experts and Security Authorities The Author Florian Brauner studied Rescue Engineering with focus on Civil Protection. For several years, he has been researching the effects of security measures. He currently works as a postdoctoral research associate at the University of Wuppertal and as security expert for Critical Infrastructures.