By the looks of things, Google's self-driving cars have been learning a lot in Austin, Texas. In its first report since it began testing autonomous vehicles in the city, the company details the challenges its cars have had to face while driving on its roads. For instance, they've been spotting and avoiding a lot of deer, some of which might have ended up as road kill if they happened to come across ordinary vehicles instead. The system also had to learn to identify new infrastructure, such as horizontal traffic signals. Google has learned, however, that one of the major problems it has to tackle is pedestrians stepping off the curb onto the road while hidden by other vehicles.