If you’re having trouble walking on your own, check out Peter Treadway’s motorized shoes. His shoes are designed to "fill the gaps" that public transit leaves so you can get around quickly and efficiently.
The shoes are designed so you can either ride your bike with them or zip along at 15 mph on the sidewalk. Peter Treadway’s mechanism clip onto your normal shoes, and it comes equipped with a set of wheels on the side for faster transportation. He may or may not have gotten the inspiration for the Treadway shoes from rollerblades, but who knows?