Be that as it may, this is about personal transportation and it will center mainly on the two-wheeled variety.
The bicycle hardly needs any introductions in that regard, it's been around for more than a hundred years and is a durable, simple machine that works.It is a multiplier of effort, a raiser of efficiency, a freedom maker.
And much fun. While I don't think the bicycle needs much help in this regard either.... I do at times.
I love the pure, sweet functionality of a well tuned bike and want to impact that as minimally as possible. As I grow a older I still love the the exercise I get pedaling ......but perhaps just not all the time. With that in mind, I've been exploring some power assist options and, I must honestly report, without which my time spent cycling would greatly diminish.
Electric assist might be applied by an Ehub, brushless motors that have regenerative braking that can be used to trickle charge a smaller_than_usual bike battery pack to keep weight down.Best would be ideally a combination of the two, a hybrid ICE/Ehub equipped bike that could get 300+ miles to a gallon of gasoline with minimal or almost no electric outlet charging.
Perhaps more appropriately we should make tribrid power: human/ICE/electric.There was a day when mopeds were popular, back in the 1970's with the first oil price shocks. They still are somewhat popular in certain places in the world. They were fun but not too practical as bikes. They are heavy, often weighing between one and two hundred pounds and damn near impossible to pedal as a bicycle. In fact, the pedals were only used just to get them started.

What I am proposing is more appropriately called a PEDMO, peddling as the first priority and the motoring aspect as an ancillary but integral, assisted part of the machine. The functionality of the bicycle remains intact and the rider simply has some options to increase range and load carrying capability.
Perhaps, along these line, a fully realized PEDMO would be a tribrid in a longtail or cargo bike.



Next to come: bike choices, powering options and......the law.