The total cost of traffic associated with lost time and wasted fuel exceeds $100 billion per year. As time slips away, idling vehicles add pollution, which has environmental and health consequences, including contributions to climate change. Long-term exposure to vehicle exhaust is associated with respiratory problems, especially in children.
Another toll is to psychological well-being, stemming from the sense of helplessness we experience in traffic, and its unpredictability. This, too, can be quantified. One study found that to save a minute of time spent in traffic, people would trade away five minutes of any other leisure activity. Another study found that we deal better with the commuting delays that we can anticipate.