The rapid development of intervehicular communication technology, coupled with the United States department of transportation (USDOT)'s vehicle infrastructure integration (VII) initiative, will soon enable a new class of in-vehicle applications such as cooperative driving assistance systems (CDASs). An engine model with reasonable accuracy and excellent computational efficiency is called for to facilitate the development of such systems. This paper presents and formulates three candidate models (Models I, II, and III), among which Model I is an existing one, and the other two are new. Their performances are evaluated based on a system of metrics including accuracy, accessibility, computational efficiency, formulation, and the need for calibration. Overall, Model II outperforms the other two and appears promising to fit the need of the particular application.