One of the greatest allures of self-driving cars is the prospect of never needing your own vehicle -- you could just catch robotic rides whenever you want personal transportation. Well, Singapore is about to explore how well that concept works in practice. The city (with MIT's help) is opening up one of its neighborhoods to autonomous cars next year to see how well they could eliminate traffic congestion. Ideally, you'll use these driverless vehicles like short-range taxis or Uber cars: hail one whenever you need to get to the airport or train station and keep another privately-owned car off the road. That's particularly helpful in Singapore, where the extreme population density (19,725 people per square mile) has led to strong government incentives for using mass transit.