The default speed limit in the state of Iowa changed from 55 to 60 miles per hour on any road not already under a speed limit requirement effective July 1, 2026, according to information provided by the Iowa Chapter of the American Public Works Association.

The passage of Senate Bill 378 resulted in modifications to Iowa Code 321.285(3).

The bill was signed into law by Governor Kim Reynolds.

The legislation made other changes to various sections of Iowa Code 321 to adjust provisions relating to speeding violations that reflect the adjustment from 55 mph to 60 mph.

The state’s APWA indicates the most common use of the default speed limit is on two-lane paved rural roadways, including on state primary and county roadway systems.

While there are some multi-lane roadways with a 55-mph speed limit, those limits have mostly been established through specific engineering and traffic analyses and generally will not be increased to 60 mph, officials said.

The Iowa DOT is working to update most signs, using aluminum overlays, on the primary roadway system starting on July 1, 2026, with priority given to the most heavily traveled roads. County governments are responsible for updating signs on county roads.

It’s estimated that the Iowa DOT will need to change approximately 1,800 existing 55mph signs on the state primary roadway system to 60 mph. The initial process will cost about $270,000.