It is widely recognized that the transport system contributes significantly to current environmental problems such as global warming, as well as to health issues caused by emissions and lack of exercise. For the transport system to contribute to sustainable development, the link between economic growth and growth in motorized transport must be broken. Since high population densities and shorter distances provide greater potential for efficient public transport as well as for walking and biking, the highest potential for change is in urban areas. As a large proportion of urban travel consists of home-to-work travel, such travel will be our focus in this paper. More specifically, this paper aims to analyze the factors that determine mode choice in situations where bicycle and walking are competitive options and to contribute to the knowledge of the conditions under which public transport can be a competitive alternative to the private car. The results of this study could be used to devise policies for reducing car dependency in urban areas. The results show that even if it is possible to attract new passengers to public transport through changes in the public transport system (i.e., reduced fares or reduced travel time) few of these new passengers will be shifting from private car use. To achieve a shift from private car to walking, bicycling or bus riding, such policies must be combined with restrictions (and/or cost increases) on car use.