1. A method for determining and recognizing types of vehicles passing a check point, which comprises: up-loading an EM algorithm into a CPU; collecting vehicle data as vehicles drive past a check point; entering said data into said CPU said data being representative of essential characteristics of vehicles; processing said data by said EM algorithm to produce an output model of the traffic volumes of the various types of vehicles; and utilizing said output model to forecast future road maintenance costs and/or to plan and design future road networks