I. Introduction
The advanced driver assistance systems (ADASs) and active safety control (ASC) systems have been widely deployed in modern vehicles. These systems have significantly contributed to the improvement of vehicle driving safety, comfort, and efficiency. In the aspect of safety, the prediction of vehicle speed plays an important role in the system. For example, forward collision warning (FCW) and automatic emergency braking (AEB) systems are strongly dependent on the prediction of the vehicle speed with respect to the lead vehicle. Inaccurate speed prediction may cause false FCW positive or unwanted AEB application.