I think the problem here is that people are conflating an enforced stop - hitting a rock - with a normal braking stop, and even then with an emergency stop.
If the issue is - is an electric skateboard more dangerous than a bike? well, then of course it is. You're less visible, less stable, and have less braking ability and much smaller wheels.
But that's not to say you can't safely brake a skateboard without throwing yourself off the front. Like any device - motorised or not - it's up to the operator to control their speed for the conditions.
I totally agree. If you run into something on either vehicle it's going to hurt. If you aren't wearing a helmet, you could really get hurt. It is pretty apparent with the behavior of typical commuter boarders vs. bicyclists that they know which is safer. Most cyclists on streets actually don't wear helmets. Most boarders do.
With regards to breaking when you don't have a rock, curb, door in your face...You can program anti-lock braking into an electronically controlled breaking system. If you have enough understanding of the friction of the rider to the board and the boarder is experienced enough to know how position themselves during braking, that system should win as it can avoid skidding. Regarding experience level: on a bike it takes some experience not to just use the front brake only and drop your head on the pavement.
Until we see some stats about which group actually sustains more serious injuries, commuter bicyclists or commuter boosted boarders, the jury is still out.
This is a fair point. The only note here is that the "enforced stop" as you put it is a function of the wheel diamter. If you think about making a wheel "non-round", its a function of the surface hardness of the wheel (ability to deofrm) and the relative size. so a 1/2 inch rock is just so much more likely to hurt a 2inch or whatever wheel than a 17/21/26 or whatever (would be like hitting a 6-8inch piece of concrete).
The frequency of this hazaard is more the problem. I skated in college to work all the time, but had the benefit of clean/smooth/concrete. It was a great mode of transit, for that. Who knows maybe someday the will have such lanes for these things?
& Obviously, the enforced stop scenario sucks on bike. Think, NYC taxi-cab doors, and etc. So thats fair.
If the issue is - is an electric skateboard more dangerous than a bike? well, then of course it is. You're less visible, less stable, and have less braking ability and much smaller wheels.
But that's not to say you can't safely brake a skateboard without throwing yourself off the front. Like any device - motorised or not - it's up to the operator to control their speed for the conditions.