Cars are an unspoken tragedy
As social theorist Ivan Illich noted in his many jeremiads against the automobile, technologies as pervasive as the car can begin to bend the rest of the world, inverting the priorities of planners to favor the needs of cars over those of people. And it's not just that we're addicted to oil—though transportation recently passed energy as the number one source of carbon emissions in the United States, and the sector is responsible for 15 percent of emissions worldwide.
Also tragic, though perhaps less spoken of, are the deaths accepted as the price of human mobility. More people are killed by car accidents every year than by AIDS and murder combined, and they cost the United States an astonishing $1 trillion a year, more than 5% of GDP.