People in highly developed countries are getting older and older. They want to be mobile in old age, but often have problems in road traffic. Even though they often pay a premium for age-appropriate products that increase safety, the demand for driver assistance systems among older drivers has so far been low. This book summarises the results of the ALFASY (ALtersgerechte FAhrerassistenzSYsteme) project, in which an acoustic driver assistance system is being developed and built to meet the needs of the steadily growing group of older drivers. Technical, psychological and economic aspects were investigated.