The longer semi-trailer that was used in the demonstration in June uses one of several steering types available to over 30 different models of trailer in the trial. It was, therefore, not representative of the full range of vehicles in the trial. The longer semi-trailer trial is first and foremost a research trial. We are monitoring all the different trailer types in the trial in order to assess their performance in the real world. All of the longer semi-trailers must comply with the manoeuvrability requirements set out in national construction and use legislation and so are able to match the actual performance of existing semi-trailers and are suitable for use on the road. Indeed, some longer semi-trailers have an outswing of only 250mm which is equivalent to, or less than, a 13.6m standard sized semi-trailer or a standard length bus.