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> I sometimes imagine what could happen if the software glitched and cranked the throttle 100% forward or back

This has happened to cars too.

> take back street space from the monoculture of heavy, dangerous, energy-intensive vehicles.

This is crucial I think, we need to be able to get from A to B free from a risk of getting flattened by a 40 ton truck

A OneWheel's wheel never disengages with the motor. It is incapable of coasting. So small wheels at the edge of the board would accomplish nothing.

The motor doesn't have to disengage; when unpowered it turns into a freewheel. The onewheel is perfectly capable of coasting, that's not what causes the crash.

It's the stance of the rider (leaning forward) combined with the sudden lack of acceleration from the motor which disrupts the equilibrium of forces and causes the ensemble to tip forward -- then it all comes to an abrupt stop because the leading edge digs into the ground.

Are you suggesting this as a fix? The wheel never turns on its own, powered on or not. I've put thousands of miles on my pint. I am assuming the onewheel engineers have good reasons for making that choice.

There is a third party accessory to add front wheels called Fangs. They were initially very popular, but most people ended up getting rid of them because they end up making crashes worse. When the front of the board is down, it desperately dumps as much power into the motor as it can in order to attempt to bring the nose up to level, but if it is unable to level out you just end up adding more speed to the inevitable fall.

These devices do have their value, but most users would be better off cycling or walking. From public health point of view replacing cars with these is only a minor improvement.

Some very good points here. What happens to a Segway when it runs out of battery?

Since we’ve not heard stories of it being involved in deaths I assume that the battery stops providing propulsion score it stops providing gyro. (And depending on how the gyro is designed it might keep spinning long enough for it to slow down and stop.)

Ironically false, former Segway company owner died on his Segway https://en.wikipedia.org/w/index.php?title=Jimi_Heselden#Dea...

But “backed his Segway off a cliff” is very different from Segway bucked him into the concrete.

> What happens to a Segway when it runs out of battery?

A Segway needs electricity to balance itself, so my guess is that when it gets close to running out of battery, it stops by itself and refuses to continue.

Though they have failed in the same manner as the Onewheel, but less often and their top speed is lower IIRC.

I’d be willing to bet they limited their speed then stopped before the battery fully ran out to prevent this exact situation.

From trading the other comments, it seems the Onewheel is just glitchy. They certainly must also have a low-battery cutoff, but I bet it's not accurate in all ranges of temperature and with aged batteries.

The Segway has redundant control circuitry, motor windings, and battery. If there is a failure of any of these I believe it will fault and perform a controlled stop.

One of the reasons the Segway was so expensive is they built it like medical devices, with tons of redundancies in its systems for this exact reason. So if one computer glitched out it wouldn’t just chuck its passenger head over heels.

As we know, once hoverboards got really popular the cheap ones (perhaps most?) were NOT built that way. I saw someone nearly faceplant when theirs ran out of battery and stopped on a dime.

Hoverboards are just about the only thing I can think of that look intrinsically more dangerous than a onewheel, just looking at it from a physical design perspective.

My ninebot scooter (maybe not what you're asking, but it's a Segway product) slows down until it can't carry you anymore. First it just can no longer achieve the maximum velocity, then soon it can no longer reach standard speed, and then you're limping along at 4mph and you can no longer climb any grade without pushing. Finally you're pushing.

It's not particularly usable as a scooter without the battery.