In Kara Kockelman’s transportation models, there is no place to hide. The civil engineering professor crunches data on where people shop, work and go to school, what kinds of vehicles they buy, real-estate development trends and demographics to help devise optimal transportation policies. Her results are sometimes provocative: for example, from traffic data, she calculated that a large SUV slows traffic by spending as much time lumbering through an intersection as 1.41 passenger cars. Kockelman says, “We can’t build our way out of congestion,” and argues that road users should therefore shoulder the costs they impose on others. Her studies support, for example, the selective enactment of something called “credit-based congestion pricing”: drivers would be allotted a certain number of commuting trips, which they could use or trade, the way power plants trade emissions credits. Such ideas are not particularly popular, but, Kockelman maintains, “I divorce myself from the emotions of the issue and allow the data to tell me what’s happening.” And Kockelman practices what her studies preach: she takes the bus to work.