For the "spooky"s, the law used to be the same as electric, except they had a cylinder bore size limit.
Now, they still have the same limitations (the law for those did not change at all, other than to specifically exclude electrics from that section of the law), while electrics have the one class with higher speeds (but more restrictions in other ways).
BTW, one side effect of the exclusion of electrics from that section is that now they are *not* motorized bicycles, so technically any signage/etc excluding motorized bicycles from an area no longer applies to electrics. (I had to re-add the strike-thrus of "electric" so if I missed any let me know and I'll go back and fix it).
28-2516. Motorized gas powered bicycles or tricycles; definition
A. Notwithstanding any other provision of this title:
1. A certificate of title is not required for a motorized electric or gas powered bicycle or tricycle.
2. Registration is not required for a motorized electric or gas powered bicycle or tricycle.
3. Vehicle license tax is not imposed on a motorized electric or gas powered bicycle or tricycle.
4. A motorized electric or gas powered bicycle or tricycle is exempt from the provisions of section 28-964 relating to required equipment on motorcycles and motor-driven cycles and from the provisions of title 49, chapter 3, article 5 relating to vehicle emissions inspections.
5. A driver license is not required to operate a motorized electric or gas powered bicycle or tricycle.
6. A motorized electric or gas powered bicycle or tricycle may use rights‑of‑way designated for the exclusive use of bicycles.
7. A motorized electric or gas powered bicycle or tricycle is not subject to chapter 9 of this title.
B. This section does not prohibit a local authority from adopting an ordinance that regulates or prohibits the operation of motorized electric or gas powered bicycles or tricycles, except that a local authority shall not adopt an ordinance that requires registration and licensing of motorized electric or gas powered bicycles or tricycles.
C. For the purposes of this section, "motorized electric or gas powered bicycle or tricycle":
1. Means a bicycle or tricycle that is equipped with a helper motor that has a maximum piston displacement of forty-eight cubic centimeters or less, that may also be self-propelled and that is operated at speeds of less than twenty miles per hour.
2. Does not include an electric bicycle."
Electrics usage (also another section specifically excludes electric bicycles from being "vehicles", in case signage excludes vehicles):
67. 68. "Vehicle" means a device in, on or by which a person or property is or may be transported or drawn on a public highway, excluding electric bicycles and devices moved by human power or used exclusively on stationary rails or tracks.
28-819. Electric bicycles
A. An operator of an electric bicycle is granted all the rights and privileges and is subject to all of the duties of a person riding a bicycle. Except as otherwise provided in this section, an electric bicycle is subject to the same provisions of this title as a bicycle.
B. An electric bicycle is not subject to the provisions of this title relating to certificates of title, registration, vehicle license tax, driver licenses or vehicle insurance.
C. Beginning January 1, 2019, manufacturers and distributors of electric bicycles shall apply a label that is permanently affixed, in a prominent location, to each electric bicycle. The label shall contain the classification number, top assisted speed and motor wattage of the electric bicycle and shall be printed in at least nine‑point bold type.
D. A class 1 electric bicycle or a class 2 electric bicycle may be used on bicycle and multiuse paths. A local authority or agency of this state having jurisdiction over a bicycle or multiuse path may prohibit the operation of a class 1 electric bicycle or class 2 electric bicycle on the path.
E. A class 3 electric bicycle may not be operated on a bicycle or multiuse path unless it is within or adjacent to a highway or roadway or unless the local authority or agency of this state having jurisdiction over the path allows the operation.
BTW, there is a specific definition of "manufacturer" in this section that does not include anyone except those making motor vehicles, trailers, and semitrailers, so I don't know that section C above can use that word without redefining it:
34. 35. "Manufacturer" means a person engaged in the business of manufacturing motor vehicles, trailers or semitrailers.