> The maximum legal speed of the vehicle would be limited to only 15 miles per hour (24 km/h); it could not weigh any more than 60 kilograms (130 lb), including the battery; and its motor could not be rated at any more than 250 watts.

It's interesting that these are still essentially the regulations for e-bikes in the EU today, I guess slightly relaxed (25km/h, 250W average only but can peak higher).