So like many posters have said before just limit your project to under 50cc and top speed of 20 mph. Of course you cannot tell the size of any engine unless you actually know what it is or it is stamped somewhere on the nameplate, etc - which no cop is going to do, and if it looks small you might be able to get away with that in court if you provide some evidence. Limiting speed is as easy as a throttle stop or just not exceeding 20 mph.

Either way the laws seem to be designed to discourage people from riding them on streets, sharing them with cars, probably because kids would take advantage of it and this raises issues with safety if it cannot be regulated, which is also why they require minors to wear a helmet.

I think if any of you had a reasonable bike that fit the state guidelines and had the state codeified law printed as proof to show a cop, and you get a citation, then merely go to court and stand firm for your case. I bet you the cop will not even show up for the case if he isnt fully sure of the law and they will quickly drop it.

If enough people catch on to this and start riding them, it will become more acceptable and tolerated by drivers and the police alike as long as people dont become careless with it.