Psychological factors that influence car-following and car-following model development

This commentary on Brackstone and McDonald’s (1999) historical review of car-following models focuses primarily on five issues: (i) Why has so much effort been devoted to car-following models? (ii) What assumptions do car-following models make about driver behavior? (iii) What factors influence car-following? (iv) What improvements can be made to car-following models? and (v) Do we need a ‘normative’ model of driver behavior? The review concludes that differences between the approaches of traffic engineers and traffic psychologists to activities such as car-following have not led to a common understanding of behavior, which is required if the challenge of anticipating how people will drive in other circumstances with different in-car systems is to be successfully overcome.     

American values and contraceptive acceptance

A number of individual personality factors and social norms may be associated with reproductive confusion and/or irresponsibility. More specifically, the values underlying common American social norms may contribute to ineffective birth planning in the following ways: 1) The traditional roles of women in our society seem to encourage parenthood. The rule has been early marriage, closely spaced children, and few alternate sources of satisfaction or self-esteem. 2) Our culture strongly encourages family life. Children are a symbol of normalcy. 3) The importance of sexual enjoyment per se often conflicts with contraceptive use. Conversely, innocence is also valued and also contributes to unprotected sexual activity. 4) Religious reasons or adherence to concepts of natural law are almost always given by people opposed to contraception. 5) Health is important to Americans, and birth control methods negatively affect health in real and imagined ways. Social norms, though changing, remain essentially congruent with former contraceptive technology and former ideologies, customs, and dreams.The Rev. Jane R. Rzepka is a Unitarian Universalist minister engaged in the Ph.D. program at the Graduate Theological Union in Berkeley. She has been associated professionally with the family planning field since 1972.