The paper presents the development and perfomance results of a new 'universal' coach safety twin seat (patent pending) which carries three-point belts, but also protects occupants sitting behind. Four main scenarios investigated comprised an empty and fully loaded seat impacted from behind by unbelted or lap-belted dummies. The extreme 12 g reverse acceleration pulse was applied on a HyGe sled rig and the pitch of 750 mm was interpreted as 'spacing' as deñned in the ECE Regulation 36. All the injury criteria specified in the ECE Regulation 80 were met in both Hybrid II and Hybrid IH dummies, as well as the Hybrid III neck injury levels. The seat performed well with 95 % and 5 % dummies, as well as with a pitch of 650 mm, and it passed the 76/115/EEC belt anchorage test. The mass of the feasibility prototype twin seat with one leg and anchorages is 36.3 kg, it is made using conventional materials and production techniques, demonstrating full technical and commercial feasibility.