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Official websites use .gov
A .gov website belongs to an official government organization in the United States.

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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.

Zip and Audio Files

Due to the risks involved in hosting native, binary encoded content that can be exploited to compromise a visitor's computer and deliver malware (malicious software), audio files are not hosted on the DOT website. Zip files may be hosted on the DOT website using a Secure Copy Client tool for transferring files securely between computers using an SSH connection.