The development of map database specifications that will enable or improve driver safety assistance systems is a topic of active research. In this context, data requirements are proposed for an advanced curve-speed warning system. Both the content of the database and the accuracy of the needed road-geometry data are addressed. First, some possible drawbacks of previous proposals in this field are sketched. Then, a model is presented to compute the highest safe speed of a road section, given three distinct submodels: vehicle dynamic, infrastructure characteristics, and driver behavior. A case study illustrates how this model may greatly improve driver suitability of curve-speed warning-control driver assistance. A sensitivity analysis formally demonstrates that the requirements concerning road-geometry data are compatible with existing low-cost measurement devices. Finally, some critiques and additions to previous works concerning map database enhancements are formulated.