I can shed some light on the "old" Arizona "moped" law and why it has evolved because I was in the thick of it.
In the late '70's, Honda came out w/the first of the Express models, followed by Yamaha w/their QT50 Yamahopper and the Suzuki FA50. These were basicly mopeds w/out pedals and their single speed 49cc engines would propel them to approx. 28 mph. These "nopeds" were a moderate success.
In 1984, Honda introduced a line-up of true motor scooters, that is, they had sm. wheels, floorboards and were encased in plastic bodywork. Ranging from 50cc to 125cc, the line-up was expanded w/ 150cc and 250cc models in '85. But for this narrative, we are only concerned w/ the 50cc models, specificly the ubiquitous Spree and how it fit in w/ Honda's strategy to market scooters.
At $399 MSRP, the Spree was the "entry level" scooter, equal in performance of the nopeds, being if anything, with it's single ratio trans, a bit slower(One mag. tester described it as "having all the zippyness of a speedy glacier").
Although they were promoted as needing no registration, insurance or license(widely and falsely thought by wishful types, that no driver's license was required). Again sales were good, but not great. Certainly not good enough for Honda's liking and I was told later by a Honda Rep. that at this point, it was decided to "flood" the market w/these little buggers w/ the anticipation that the buying public would soon be hooked and move up to the larger models.
Enter the $199 Iowa Spree.
Although I didn't know it at the time, a de facto national moped guide-line was developed based on the moped law in Iowa and when they started arriving by the truck-load at the dealership where I worked, I remember thinking; "Gee, they must sell a lot of scooters in Iowa". They were restricted to 25 mph w/ a smaller muffler and only differed visibly by a Honda decreed red "dot" of spray paint on the underside of the seat(although some less-than-scrupulous dealers skipped this step and sold them for full retail).
They sold like the proverbial hotcakes and soon the U of A campus and surrounding landscape could only be described as "scooter chaos". They rode and parked them on the sidewalks. They rode "two-up". They abandoned them behind the Frat houses at the end of the school year(By now, I had opened a scooter shop and actively became a "dumpster-diver", asking permission from the summer staff). This scene became further exacerbated by the larger CVT equipped scooters, like the Aero 50, that could reach 42 mph(given a long enough straight), but still fell under the 49cc moped law.
The "City Fathers" took note and were not happy.
By the early '90's, graduating students, instead of buying larger model scooters, bought BMW cars instead and the scooter prices went up.
"The "scooter boom went bust".
I sold my inventory to a couple of guys in Mexico, bought a big motorcycle and took a "see America" trip that would last a year.
And the moped laws? The State Legislature, "still w/ a bad taste in their mouths", stiffened the reg.s, although Az., by National standards, is still somewhat liberal.
