How can you tell if it's alleviating traffic problems? I don't think the effect is large enough to tell through a gut check.

I haven't had too much issue with them as a pedestrian, though I'm baffled as to why they're forbidden from using bike lanes on roads and are therefore forced to use the footpaths. They travel with the same sort of speed as a bike, and the user wears a helmet. Surely the risks are pretty equivalent.