Makes my 2000 lime green Honda Insight, that has been my main driver since new, appear a gas hog at 70 m.p.g.
I like it as a bicycle alternative rather than a car alternative for my environs, as the average non freeway speed limit is 45 m.p.h. where I live.
So best relegated to the bike lane.
Modifications/ improvements to increase speed are probably not a good idea as they would result in the legitimate need for further safety engineering, which would increase weight, pedaling effort and the already somewhat pricey cost for this market sector.
So design probably best left alone, except to hopefully bring down cost with increased higher production effects of lowering cost / unit.
Usefulness still most dependent on speed limits near where you live and travel to on a routine basis.
Sorry to have to say it doesn't work for me due to this consideration.
