scope:

This informational report explores the history of corner visibility guidelines, compiles and compares the intersection corner visibility policies and practices in place in the United States and in certain foreign countries, and addresses whether policy consistency on the topic exists. The Technical Council Committee conducted an in-depth listserv/MuniCode search using "Sight Triangles", "Corner Clearance", "Intersection Sight Distance", and other associated terms. In addition, committee members obtained municipal, local, and state government codes, policies, guidelines and handbooks related to intersection or driveway sight distance triangle regulations. A random sample of 85 guidelines from this extensive body of research (more than 850 were collected) was summarized in a database in order to identify recurring methods and requirements.