These are department rules in addition to the requirements in 29 CFR 1910.22 and 1926.20:
Note: For further information regarding safety vests and clothing that are acceptable for providing to employees, see American National Standards Institute/International Safety Equipment Association (ANSI/ISEA) standard 107 - High-Visibility Safety Apparel and Headwear. Vests and clothing that are accepted under this standard typically do not become unacceptable upon publication of a later edition of the standard.
Note: Under s. 349.065, Stats., traffic control devices must be designed, installed and operated in accordance with the uniform traffic control devices manual adopted by the department of transportation under s. 84.02(4) (e), Stats. The manual may be obtained from the American Traffic Safety Services Association, 15 Riverside Parkway, Suite 100, Fredericksburg, VA 22406-1022, telephone 800/231-3475. Electronic copies are available at the Federal Highway Administration website at http://mutcd.fhwa.dot.gov/.
Wis. Admin. Code Department of Safety and Professional Services SPS 332.21