This Engineering Brief provides guidance for identifying situations where a taxiway could be mistaken for a runway and provides mitigation strategies for dealing with the problem. These standards and recommendations will be incorporated into changes in several Advisory Circulars, including 150/5300-13, Airport Design, 150/5340-30, Design And Installation Details For Airport Visual Aids, and 150/5340-1, Standards for Airport Markings. In the interim, due to a number of recent incidents, use this guidance for addressing the problem.