An official website of the United States government
Official websites use .gov A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Portions of the Department of Transportation are currently in shutdown/furlough status due to a lapse in appropriations. Please continue to monitor this page for updates on DOT’s operating status.
APPENDIX C. LOGICAL MODEL ENTITY RELATIONSHIP DIAGRAM
This diagram expands on the conceptual model to demonstrate the structures within a relational database. There is an ERD for segment, intersection, intersection leg, interchange and curves and grades.