Salvaged and/or re-galvanized guardrail on construction projects

Montana currently permits reusing removed rail from projects occasionally by special provision or change order.
How does the state agency verify and certify that the salvaged and/or re-galvanized guardrail meets state specifications? – Salvaged rail from current projects would have met specs at time of original installation. Visually inspected for condition (no damage).
How long has the state agency allowed the use of salvaged and/or re-galvanized guardrail? – In excess of 20 years. Until approximately September 2001 the Standard Specifications permitted reusing in-place guardrail.
How is salvaged and/or re-galvanized guardrail bid in a project? – Currently it is not. Pre-2001, a bid item was provided in the specifications. Contractor would review project before bidding to estimate quantity of reuseable rail.
How is it documented that using salvaged and/or re-galvanized guardrail will result in significant savings? – The price is adjusted in a change order.