“I think we have a cultural affinity for technology that reflects optimism, but we all make poor forecasts,” says Jim Moore, director of the Transportation Engineering Program at the University of Southern California. He says that any tech that’s based on new standards for infrastructure, in particular, is risky. It requires sweeping changes, investments, and it penetrates the market slowly. That’s why monorails, despite their advantages over traditional rail locomotives, have largely been relegated to theme parks and Simpsons episodes.