Work should be arranged so that road going vehicles do not drive onto mud on the site. This includes laying site roads and using site based plant to move materials to holding areas at the edge of a site road. If wheels and ledges are likely to pick up mud the site should anticipate this and install a wheel-wash. Either routinely, or as a back-up plan, the site should have arrangements in place to call in a road sweeping machine at short notice. Site management should be monitoring conditions outside the site regularly during periods of material movement.