City auto traffic in the US is weirdly fast - it's 30 mph instead of 30 kmph. These devices have no trouble at 18mph but America decided it has to be faster because it built things so far away.
I don't know about the particular mopeds in the article, but for instance the Gogoro's that are used by Coup in Europe can go up to 90-95 km/h and fall into the 125cc category unless they are artificially restricted to 45 km/h (to allow for more people to be able to use their service).
Most cities in Europe have a speed limit of 50-60km/h only a handful of roads are limited to 30 and 25 km/h and those are often mixed roads or a parking lot :)
