Abstract
As a part of its continuing work in the development and improvement of highway design controls, the American Association of State Highway Officials recently examined the stopping sight distance values as adopted for use in its design policies and standards and made changes therein. The present values are retained as "minimum" design values and a second set of "desirable" values has been added to be used as a basis for design wherever practicable and feasible. In no case should stopping sight distance be less than the "minimum" values. The details of the changes and the reasons therefore are discussed here.