This paper examines some recent developments in the field of weighing in motion (WIM). It is divided into two sections covering systems currently in use today and new or future developments. Systems examined under the first section include the following alternative highway speed WIM methodologies: 1 bending plate systems; 2 shallow weighscale systems; 3 deep pit weighscale systems; 4 bridge systems. The recent developments examined in the latter section of the paper include the use of capacitive and piezo-electric systems for weighing in motion. Prospects for further development in these areas are also outlined.