Traffic control: speed restrictions; definition of school zone; modify. Amends sec. 627a of 1949 PA 300 (MCL 257.627a).

HB 5533 modifies Michigan's school zone speed limit rules. It defines a "school zone" as property within 1,000 feet of a school building and sets a reduced speed limit (minimum 25 mph) that applies up to 30 minutes before school starts and until 30 minutes after school ends, rounded to the nearest 5 minutes. School superintendents can adjust these timing windows for off-campus lunch or different school hours. The bill also requires "All Year School" signs for year-round schools and mandates that all signage follow Michigan's traffic control device standards. This directly affects drivers near schools and school officials managing zone timing.