It's admirable that more and more human-powered vehicles are coming to the public attention. (Follow the link in the article to the human-powered 4WD SUV and check out the pictures.)
I looked at the images of the pedal quad hopping rocks, getting all askew on a downhill run on a goat trail, and sliding sand dunes. First thought was NOT "Wow! What an interesting vehicle!" First thought WAS "Clever bike!"
I can't help it - I rode bikes, I know they have a certain speed range and power-speed curve that limits them to certain terrain, certain speeds, and certain athletes or couch potatoes. For me, a human powered machine is out, unless by "human powered" the designer meant "shovel a few humans you don't like into the fire box and then move Lever A to positi..." Emphysema does that to you.
But even when I was healthy and climbing 300metre antenna towers two and more times a day, I wouldn't have considered a bike to be anything remotely like a vehicle. For a start, in the Northwest where I was, a vehicle had a roof and air conditioning. And it covered between 400 and a thousand kilometres a day. Without me having to tow along a tanker of water to stay hydrated in 48C temperature days. Oh yeah and the tyres had to be made out of hardier stuff to drive over rocks and bitumen hot enough to slow cook eggs.
Looking at the action images, I had to admit they looked like fun. Except. I, like hundreds of others who will look at the pictures, will see a bike and wish there were an an engine. We're grown lazy from having the false impression that some deceased dinosaurs and trees pushing us around is a right.....