external costs of cars

in Manhattan, driving a car during the week creates $160 of negative externalities

Source: Google's Self-Driving Cars Miss the Problem With Mobility in America | New Republic
added 2014-06-01T20:23:09Z by anders

cars tend to drive closer to bicyclists wearing helmets

That comes from Ian Walker, who set up a bicycle with sensors and drove around the city. Vehicles tend to crowd closer to him when he was wearing a helmet than when he wasn’t.

Source: The weird, counter-intuitive science of traffic jams
added 2013-09-25T14:47:08Z by anders