MI SB1121

Expands definition of "implement of husbandry" to include farm tractors, self-propelled application-type vehicles, farm wagons, farm trailers, vehicles adapted for lifting or carrying other farm equipment, and substantially similar equipment used for agricultural production.

Clarifies that implements of husbandry are excluded from definitions of "semi-trailer" and "trailer" under Michigan vehicle code.

Allows motorcycle operators and riders aged 21 and older to forgo crash helmets if they have 2+ years of motorcycle endorsement experience or complete a motorcycle safety course, provided they maintain first-party medical benefits insurance of at least $20,000.

Requires operators with riders to maintain $20,000 per person in medical benefits coverage, though riders with their own $20,000 coverage satisfy the requirement independently.

Mandates seat belts for occupants of autocycles equipped with roofs meeting crash helmet standards, and exempts such vehicles from helmet requirements.