It may still just be in its infancy, but Hyperloop One is definitely making progress with their high-speed transportation system. They recently sent their mag-lev test capsule rocketing down its vacuum-sealed tube at a top speed of 192 mph. Their goal is 670 mph.
While sitting in traffic one day, Elon Musk had a crazy/brilliant idea – to build a network of underground tunnels which would rocket cars between destinations. A recent concept video envisions cars descending via street elevators, and zooming around on autonomous sleds.