Self-driving cars have been envisioned for decades but technological challenges prevented fully autonomous vehicles. In 2007, DARPA held the Urban Challenge to promote development of self-driving cars that could navigate traffic. The Carnegie Mellon University team won with its entry named BOSS, which used lasers, radar, GPS and other sensors along with advanced software to safely drive itself without human input at speeds up to 30 mph through an urban environment, interacting with other vehicles. However, challenges remain around interactions with traffic lights, pedestrians and live traffic before self-driving cars can be made widely available to consumers.