Some larger gauge model railroad clubs have been using 2" x 4" recycled plastic material for track ties which have nearly an unlimited life cycle expectancy. Suppliers for recycled plastic in the 2" x 4" stock size seem to have gone out of business or have changed their marketing to other uses.
Would PT wood be a suitable and equivalent product in regards to cost and expected life cycle as a replacement for recycled plastic? Our railroad ties are directly in contact with soil and/or crushed stone ballast year round.