Though cap-and-trade policies are generally limited to business operations, currenttechnology would enable individual vehicle users to participate in cap-and-trade. Specifically, drivers could monitor their own vehicle’s pollution contribution and trade pollution credits with other drivers. Such a pollution market could operate continuously and in real time to maintain air quality. Our proposal requires each vehicle to have a dashboard PDA. This PDA would either be connected to pollutant sensors in the vehicle’s exhaust or simply estimate pollution output based on periodic emission testing. With this information, each vehicle could conduct transactions with other nearby vehicles, using software to help drivers manage their bid and ask prices based on current vehicular traffic levels. This type of large-scale m-commerce market would require a different message routingapproach than typical point-to-point routing. Each transaction, rather than involving two nodes already identified as the transacting parties, would be open-ended. Therefore, a routing approach that disseminates each bid-ask pair over a wide area is a natural approach. The Self-Balancing Supply/Demand (SBSD) protocol provides precisely this system behavior.