1. Trikes have no balance issues. you can pedal uphill .25 mph if you want.
2. Greenspeed has a trike that has been known to hold up 400+lbs people
3. It's got 3 wheels just put it on top your car and rope it down.
4. It's got three wheels you can take corners at speed without worrying about balance
5. They are heavier so they climb slower than uprights.
6. Because they are 2x as wide as other bicycles people give you more space on the roads. People have touredfaround the world on these things so they are safe on the roads.
7. Check out www.greenspeed.com.au they do a lot of custom work.