That is incorrect. IL is one state that is a gray area.

In Illinois (where I am) motor vehicles require registration, licensing and insurance..... but every vehicle with a motor on it, is not a motor vehicle. Nor does adding an engine to a bicycle legally make it a moped, or motorcycle,,, at all.

Specifically: Illinois only considers the vehicle legally a "motor vehicle" if it bears a federal-format VIN on the frame. Since bicycles don't have VINs (and serial numbers do not count) bicycles are exempt from all state-level registration, licensing and insurance laws.

The state can assign VINs to vintage motor-vehicles that did not originally come with them (pre-1930 or so) but there is no provision in the IL motor vehicle code for assigning VINs to modern commercially-built vehicles of any kind that did not receive them at the factory. Custom-built vehicles can apply for a VIN through the state, but must pass DOT requirements--which bicycles cannot pass, for multiple reasons.

And there is no prohibition of adding motors of any kind to bicycles in the motor vehicle code as well, only the requirement that bicycles must be able to be propelled by human power.

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I rode mine on public roads for one summer and never got stopped once, passed right by police cars on a number of occasions. The longest trip I took was ~75 miles one-way. I have since gotten rid of it, but only because it was a lousy build job.

Some people have been stopped and told they're illegal, but no-one I have heard of has pressed the matter into court, which is what would need to be done to prove there's nothing prohibiting them.

One guy was told by a police officer that since mopeds were soon going to require class-M licenses, that motorized bicycles would be illegal without such a license too, but that is false for the reason I already pointed out--a bicycle is not legally a motor vehicle at all.