Traffic congestion cannot be solved until we address the externalized costs of driving. Over a third of the real cost of driving is not paid by the driver, but by the public through taxes, cost of living , and quality of life impacts (see the link for charts). This means that DRIVING IS OUR MOST HEAVILY SUBSIDIZED ACTIVITY. It is an invisible subsidy, but it defines our choices. The value of these external costs is many millions of dollars per year. Using alternatives involve internalized costs in time, lost mobility, and physical risk. If we want people to use alternative transportation, we must create systems that provide fair compensation for the benefits they provide by not driving. Smartphone tracking capabilities make it possible to accurately measure the benefits provided by each participant. Carpoolers, mass transit riders, and bikers need to be compensated for the money they save the rest of us.