We wouldn't blame you for feeling that pedestrian crossing buttons are frustrating at best, and useless at worst. You might not always have a free hand, and they're so slow and clueless that it can be tempting to defy the red light. Austrian researchers might have a solution, though: have the traffic lights themselves determine your intentions. They've developed camera-equipped traffic lights that detect people who want to cross the street. The computer vision system scans a 26-by-15 feet area and sends a signal to the lights when it sees one or more people in the right position, all within a matter of seconds. It's three to four seconds faster than it would take to reach for a button, according to the scientists.