The West Somerset coroner is hearing advice on how to prevent a repeat of the crash on the M5 near Taunton, in which seven people died.
Michael Rose previously concluded that the accident was caused by dense fog, and that smoke from fireworks may have been a contributory factor, but was not the prime cause of the incident. He'll make safety recommendations after listening to the evidence of experts.
British Pyrotechnics Group say fireworks operators are now trained to take into account the risks of smoke when there is high humidity.
7 people died and 51 people were injured in the crash on November 4th 2011. 34 vehicles were involved.