Precautionary salting trials on the M62 at Goole

Two salting trials were carried out on a three-lane section of the M62 near Goole. Trial 1 was with untreated dry 6.3mm rock salt and Trial 2 was with dry 6.3mm rock salt treated with an additive based on an agricultural by-product. The de-icer was spread with the trial site open to traffic. The site was closed to traffic 2 hours after spreading and the residual salt was collected from four 1m long strips. After the salt recovery, the site was reopened to traffic until 25 hours after spreading. The site was then again closed to traffic and the residual salt was collected from another four strips. It was estimated that 14.6g/m² of the untreated salt and 17.0g/m² of the treated salt was spread to Lanes 1 to 3. After 2 hours of trafficking, the salt loss in these lanes was estimated to be 59 per cent for the untreated salt and 51 per cent for the treated salt. After 25 hours, the loss of salt was estimated to be 73 per cent for both de-icers. Most of the residual salt that was present 25 hours after spreading was trapped in the surface voids of the negatively textured surfacing.