In the U.S., most of us drive because it's so incredibly inexpensive. Steve Schoeffler, executive director of the eRideShare carpool service reports that the recent price increases "are starting to cause some behavior changes." According to Schoeffler, there are "55 new carpool listings so far today on eRideShare. Previous high for a single day was yesterday, with 42. Before that 36, last week."