How long will it take auto manufacturers to earn $1.9 billion in self driving car sales in Washington? That's about what we're paying to extend light rail to UW. Compared to the decades it might take to sell the first 38,000 self driving cars the length of time it's taken to extend Link may seem short. It took eleven years to sell the first million Priuses worldwide and the technology is a baby step compared to the leap of faith in trusting a self driving car.