If hidden costs were added to the price of a new car, they could almost double the money consumers spend on cars, according to preliminary results of a ongoing study by a UC Davis researcher. Postdoctoral researcher Mark DeLuchi found that the hidden costs -- economic and environmental effects that do not have a direct market price -- of using motor vehicles were at least $50 billion in 1990 and may have reached as high as several hundred billion dollars. "These costs may be almost as great as the direct expenses of owning and operating motor vehicles -- purchase, maintenance, fuel, registration and so on," DeLuchi says. Motor vehicles have many kinds of hidden costs, related to accidents, free parking, highway infrastructure, government support services, air pollution, global warming, water pollution and tax subsidies. For example, free parking at a shopping mall is ultimately added onto the price of goods purchased there, and the price paid for gas at the pump does not include the costs of subsequent environmental and health damage. DeLuchi's research is attempting to quantify these hidden costs and determine which are the largest. "With this information, policy-makers can think about ways to make motor-vehicle users pay the full cost of using motor vehicles," DeLuchi says. DeLuchi will present the paper to the Committee on Alternative Transportation Fuels at 7:30 p.m. Wednesday, Jan. 13, at the Hilton.