Red light, green light—no light: Tomorrow's communicative cars could take turns at intersections

· Life is short, and it seems shorter still when you're in a traffic jam. Or sitting at a red light when there's no cross traffic at all. · In Mexico City, São Paolo, Rome, Moscow, Beijing, Cairo, and Nairobi, the morning commute can, for many exurbanites, exceed 2 hours. Include the evening commute and it is not unusual to spend 3 or 4 hours on the road every day. · Now suppose we could develop a system that would reduce a two-way daily commute time by a third, say, from 3 to 2 hours a day. That's enough to save 22 hours a month, which over a 35-year career comes to more than 3 years.