Most places don't use sand alone to treat the rails after cleaning them, and haven't for a long time. Sandite is used in many places, which essentially adds so

Most places don't use sand alone to treat the rails after cleaning them, and haven't for a long time. Sandite is used in many places, which essentially adds some sort of metal shot and antifreeze to the sand. The goal is essentially that this mixture will be interspersed with the leaf gunge that accumulates over the day and both provides better traction (sand, antifreeze) and helps any track circuits to continue to function even when the tyres are unable to make direct contact with the rail (metal shot).