> The speed can be governed

You sure? Applying brakes to someone rolling downhill can make them fall because their body is still in motion, and now the scooter isn't moving at the same speed, and they were not prepared for it.

They do it through the electric engine. It's a bit of a jerky motion, like allowing 1-3 km/h over and then braking down to 20 km/h. After a while you do not even notice it.

Ideally the brake is applied to limit speed, not reduce it. To keep you capped at a safe speed, rather than allowing an unsafe speed to be reached then slamming on the brakes to reduce it.

I think they meant the scooters have firmware which can limit the top speed of the rider.

1. Not downhill.

Why not? The same brushless motors could be also used to brake the scooter could they not?

I haven't run the numbers but at that size I would expect them to get very, very warm.

Couldn’t they just do a controlled spark at high enough voltage?

1. Regen braking

Sure, up to a certain grade. But regen braking isn't working down hills like the ones in SF.

All the ones in Sweden use the electric motor to govern the speed downhill, limited to 20 km/h.

I've tested this. The fastest I could get a Voi scooter in Germany to go downhill was 27 km/h. They're limited to 20 km/h on level ground and gradually start braking if they exceed that speed downhill.

It might be possible to find a hill steep enough to overcome the braking force, or one that results in a strong enough braking force to make the scooter difficult to control, but it should be obvious to most people that attempting such a thing is dangerous.