Trials were carried out with an imported 3mm white salt and UK 6.3mm brown rock salt to determine their performance when used for pre-wetted salting. The salt distribution profile immediately after spreading was found to be slightly more uniform with the 3mm salt than with the 6.3mm salt. The percentage loss of salt during the first two hours of trafficking was estimated to be lower for the 3mm salt. From these findings, the potential salt savings were estimated to be 20.6 per cent if 3mm salt was used. However, 3mm salt costs more than the 6.3mm salt. It was estimated that there would only be a direct cost saving if the cost of the 3mm salt exceeded the cost of the 6.3mm salt by 25.9 per cent or less. However, when the effects of corrosion and environmental damage were included, it was estimated that there would be an overall (direct and indirect) cost saving if 3mm salt cost less than £40.44/tonne or £59.32/tonne when 6.3mm salt cost £25/tonne or £40/tonne, respectively. The operational advantages and disadvantages of using 3mm salt are highlighted. The main disadvantages are the need for infrastructure investment in the UK and the possible impact of using imported salt on the carbon footprint of winter service.

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