Berliners lost 60 hours to traffic congestion last year, which is something Oliver Collmann is hoping to change. The engineer spent years working on software for self-driving cars before realizing he really wanted to use his skills for things "that are more in the general interest of humankind." Having eased out of his job, he joined a group campaigning for a referendum to reduce traffic in the center of Germany's capital . "Berlin is one of the few European capitals now that are still very car centric in the traffic policy," said Collmann, who is co-spokesperson for the movement.…