HNTB Corporation is an American infrastructure design firm. [2] Founded in 1914 in Kansas City, Missouri, HNTB began with the partnership made by Ernest Emmanuel Howard with the firm Waddell & Harrington, founded in 1907.. Considered as one of the most trusted U.S.-based design firms, [3] HNTB generated a revenue of $3 billion in 2023, the second most of any …