When you're driving, it's all too easy to rage at fellow motorists who are either in a hurry or taking their sweet time. After all, you don't know the context. Are they in a real predicament, or just careless? If TUe researchers have their way, though, you'll know when to cut some slack. They've developed a mobile app, CarNote, that uses augmented reality (displayed in front of you through a periscope lens add-on) to let fellow drivers signal their intents and feelings. If you're in a rush to the hospital, for instance, you can notify commuters behind you so they don't honk their horns or chase you down. There are limits to how often you can use it, so habitual speeders can't just leave it on to excuse their behavior.