5 reasons why autonomous cars aren't coming anytime soon

In the world of autonomous vehicles, Pittsburgh and Silicon Valley are bustling hubs of development and testing. But ask those involved in self-driving vehicles when we might actually see them carrying passengers in every city, and you'll get an almost universal answer: Not anytime soon. An optimistic assessment is 10 years. Many others say decades as researchers try to conquer a number of obstacles. The vehicles themselves will debut in limited, well-mapped areas within cities and spread outward.