Traffic volume measurement based on a single smart road stud

•A new vehicle detection equipment called Smart Road Stud (SRS) based on Anisotropic magneto-resistive (AMR) sensor is proposed.•The novel algorithm of two-step extraction has been explained to get the signal of magnetic field perturbation generated by vehicle.•The novel method to distinguish extracted signals corresponding to one or two vehicles has been detailed to improve traffic volume.•Fields test including two different types of road has been implemented to verify the reliability of proposed method.