Every road's future condition is predicted from the county's own road surveys — six of them, taken between 2005 and 2021. We tested those predictions by forecasting years the county had already surveyed, then measuring how close we came. That measured miss is the "give or take" shown with every number.

Repairs restore condition by amounts taken from the county's own cost and design figures — how long a resurfacing or rebuild is expected to last. Those are engineering assumptions, worth an engineer's eye.

For the technically minded: the forecast is an age-based deterioration curve fit per pavement type to the county's rating history, checked by recursive back-testing against held-out later surveys. Beyond an 8-year look-ahead there is no survey left to check against, so the error is held at its 8-year value and the timeline is marked. The animation shows each year in two steps — that year's repairs, then the resulting road condition; the underlying model applies repairs and a year of wear together, landing on the identical year-end condition.