The City of Mercer Island has passed new regulations regarding e-motorcycles. The new rules define what an e-motorcycle is and their licensing and operating requirements. The key distinction between an e-motorcycle and an e-bike is the size of the electric motor (750KW+), lack of pedals, and frame type.
Find full information here: https://www.mercerisland.gov/publicworks/page/e-bike-e-motorcycle-safety
