The forecast is a deterministic deterioration curve fitted to Blue Earth County's own six MnDOT rating reports (2005–2021) — one curve per pavement family, no hand-tuning.

It was checked by recursive backtest: trained on the early surveys, projected forward, and scored against the later ones it never saw. Every projected number here carries that measured error (the ± band).

Treatment effects are engineering assumptions — design lives and post-treatment condition from the county's cost book, not learned from data. Beyond 8 years the horizon exceeds what the surveys can validate; the error band holds flat and is shown as such.