Not a car or bicycle, but a blend - an ELF vehicle

It's the closest thing yet to Fred Flintstone's footmobile, only with solar panels and a futuristic shape.
It's an "Organic Transit Vehicle," a car-bicycle blend also known as an ELF bike.
Mark Stewart, a 65-year-old family therapist, is taking it on a 1,200-mile journey along the East Coast Greenway, a bike and pedestrian trail that runs from Florida to Canada.
Stewart began his journey in Durham, North Carolina, on July 15. He estimates the entire trip back to his home in Cambridge, Massachusetts, will take about a month.
He says the first leg, from Durham to Reston, Virginia, took roughly five days, 60 miles at a time.

Stewart bought the ELF from Durham-based Organic Transit, which sells them for a base price of USD 5,000.