The simple solution to PMD....That would be right approach...

[hfourhappy]

allow speed limited PMDs that can only go to 15km/hr...and allowed 10km/hr on foot paths.

Of course at any speed you can hit another person walk or cycle also can bang into others. But idea ia limit type of injury.

Then impose hefty fines for importers who import illegal PMDs and those who modify it illegally....

PMD is a great technology. It transform lives. Technology is a double edge sword we need to live with some trade-offs.

Regulation if done properly allow the benefit of technology to be reaped and limit the downside.

Not feasible.
Even if impose a strict speed limit, will those bad eggs adhere to it?
Likely 100% no.
They will speed if given a chance.
They wont care for others safety.
They will speed to show off their riding skills.
Best is ban and thats it.
No more negotiation.

[hfourhappy]

It's the attitude problem of the reckless riders, they suppose to be have safety awareness in the first place.
早知今日，何必当初呢?

Those people will not follow rules.
They follow their own rules, that is speeding along the pavements.

[hfourhappy]

Who break the rice bowl?
PMD bad egg riders.
Who cause the ban?
PMD bad egg riders.
Who to blame for this?
PMD bad egg riders.