Wis. Admin. Code Department of Transportation Trans 300.20
Copies of the references are on file in the offices of the Division of State Patrol, the Secretary of State, and the Legislative Reference Bureau; or may be purchased from the Society of Automotive Engineers (SAE), 400 Commonwealth Drive, Warrendale, PA, 15096. The standards are noted in the SAE handbook, 1997 edition. Any standard or recommended practice shall be treated as an approved standard and shall not be advisory in nature.