In this paper we present a fast motion detection technique based on laser data and odometry/imu information. This technique instead of performing a complete SLAM (Simultaneous Localization and Mapping) solution, is based on transferring occupancy information between two consecutive data grids. We plan to use the output of this work for Bayesian Occupancy Filter (BOF) framework to reduce processing time and improve the results of subsequent clustering and tracking algorithm, based on BOF. Experimental results obtained from a real demonstrator vehicle show the effectiveness of our technique