In order to evaluate vehicle powertrain performances and driver behaviors, a computer aided in-vehicle data acquisition system named MOde Survey System (MOSS) is newly developed in conjunction with a motor manufacturer. MOSS is designed to be used by personnel related to vehicle emissions and energy with the aim of being cost-effective and easy-to-use. Since driving behaviors and patterns influence powertrain performance in terms of fuel economy and emissions, engineers can utilize the system for understanding the driving pattern and traffic situation quantitatively.MOSS mainly consists of an MCU-based hardware and PC-based software. MOSS logs and analyzes various data related to vehicle driving. Compared to currently-existing Test and Measurement Systems, MOSS is designed and developed for a specific goal with several unique features. These features are: 1to be able to be used as either a stand alone system(post processing mode) such as a data logging system or a real-time processing system(real-time mode) with a PC to easily visualize vehicle and traffic data during the test. 2to provide a window-based statistical analysis program which may be used with ease in analyzing driving patterns and traffic situation with logged test data files.