To reduce both petroleum dependence and the social cost of transportation in the state, California has advocated a strategy of promoting alternative fuels and alternative fuel vehicles. The California Light Duty Vehicle Conventional and Alternative Fuel Response Simulator (CALCARS) is a model that was developed to predict the potential demand for alternative fuel vehicles in California under a variety of different scenarios. In addition, as a full vehicle demand, choice, and use model, CALCARS allows an analysis of other measures designed to reduce the social costs of transportation, such as fuel and vehicle miles traveled (VMT) taxes and accelerated vehicle retirement (scrappage) programs.
The CALCARS model is updated at regular intervals to refine the forecasts of vehicle demand, choice, and use. Included in the updates are new vehicle technologies, incentives, or policies that may have recently become available. New data on consumer preferences and behavior are required to support the periodic model updates. To support the 2008 update, RSG developed and implemented paper and online stated preference surveys, which were mailed to residents and commercial vehicle fleet managers in each of five regions across the state of California. The survey collected information about the relative preferences of twelve vehicle attributes (e.g., vehicle type/size, fuel type, maintenance costs).
RSG estimated behavioral choice models using the more than 3,200 responses collected from residents across the state. Specific coefficients for each of the twelve vehicle attributes were provided to the Energy Commission for use in the CALCARS model. RSG also estimated models to estimate household vehicle ownership levels, vehicle miles traveled (VMT), the elasticity of ethanol, new vs. used vehicle purchases, and vehicle transaction and replacement rates.