[samwichse]

Originally Posted by Hersbird

Individual states could make carveouts and not require motorcycle endorsement or helmets for 3 wheeled vehicles with rollover protection and 3 point seat belts. The purpose of 3 wheels is to get around federal regulations but those don't stipulate helmets or endorsements.

From what I've found:

As of January 2018, Elio reports that only three states—Alaska, Maine, and New York—still require a motorcycle license to operate an autocycle. Additionally, only Maine's partial helmet law, requiring helmets for occupants below the age of 18, applies to the Elio. No helmets are required in the other 49 states, regardless of regular motorcycle helmet laws.