- (1) U.S. Department of Transportation, Memorandum to Secretarial Officers and Modal Administrators from Polly Trottenberg, Under Secretary for Policy, February 28, 2013.
- (2)Federal Highway Administration. Interactive Highway Safety Design Model (IHSDM). www.fhwa.dot.gov/research/tfhrc/projects/safety/comprehensive/ihsdm/
USA Banner
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.