All culverts shall have a clear width of roadway of at least twenty feet. Bridges shall have a clear width of roadway of at least sixteen feet.
Iowa Code § 309.74
Width of bridges and culverts
[C51, §517; R60, §822; C73, §1001; C97, §1572; S13, §1527-s7; C24, 27, 31, 35, 39, §4667; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §309.74]
Official source: Iowa Legislature. Reproduced from public-domain Iowa statutes; confirm against the official source for the current text. Not legal advice.