The purpose of this Request for Proposal (hereafter called the RFP) is to obtain proposals from qualified bidders who can develop and implement for the California Energy Commission (hereafter called the Energy Commission) a dynamic predictive model for transportation energy usage. This Dynamic Simulation Transportation Energy Model (DynaSim) will evaluate and incorporate, when appropriate, existing Fuels and Transportation Division (hereafter called FTD) stand-alone statistical data routine packages (Model) that will allow FTD to predict California's economic and energy usage based on the best near-term data available and to efficiently evaluate the state-wide impact of hypothetical policies and transportation fuel options.