John Cassidy, a writer for the New Yorker, wrote a blog post arguing against New York City's having installed bike lanes. Cassidy complained that the bike lanes had eliminated traffic lanes on some streets as well as some on-street parking. A writer for the Economist disputed Cassidy's argument with the following comment: "I hate to belabour the point, but driving, as it turns out, is associated with a number of negative externalities." What externalities are associated with driving? How do these externalities affect the debate over whether big cities should install more bike lanes?