Trade Transparency and Public Input Act of 2018 This bill amends the Bipartisan Congressional Trade Priorities and Accountability Act of 2015 to require the President, at least 30 days before initiating trade negotiations with a country, to publish on a publicly available website of the Office of the U.S. Trade Representative (USTR) an easily accessible portal that allows the public to electronically submit comments on the negotiations. The USTR shall also issue a request for comments through notice in the Federal Register.