In this paper we propose an extraction technique based on an active contour model (snake) considering inertia and differential features of an object in movie. In many methods for tracking a moving object, a snake is applied to a scene frame by frame, and initial positions of control points in a frame refer to results in the previous frame. We focus on inertia which works between previous and present frames. In this paper inertia is the tendency of a control point to resist changes in its state of motion in an image space. We propose an internal energy for snakes based on inertia of control points. Proposed method is applied to extract road geometry from a video camera equipped on the head of a vehicle. Internal energy functions based on differential features of road geometry is also introduced. Experimental results indicate the availability of the proposed method.