Recording, Tracking and Trending PASER Scores Over Time

A rating taken once tells you the condition of a surface on the day it was inspected. A series of ratings, taken consistently and recorded properly, tells you how quickly that surface is changing — and a rate of change is what actually supports a maintenance decision. The gap between the two depends almost entirely on record-keeping discipline rather than on the inspection itself.

Two pavements can share an identical score of six on the day they are inspected and still be in very different positions: one might have held steady at that level for several years, the other might have dropped from an eight the year before. The number alone cannot distinguish a stable surface from one deteriorating rapidly. Only a record that stretches back over multiple inspection cycles reveals which situation is which, and that distinction is precisely what should drive whether a site is treated this year or left for the next cycle.

The rating itself is only one field in a useful inspection record. Each entry should also capture a fixed location reference for the segment being rated, so that later inspections can be matched to exactly the same stretch of pavement rather than an approximate area nearby; dated photographs taken from a consistent vantage point, which allow a reviewer to see distress even when the numeric score has not yet moved; brief notes on the type of distress observed, such as transverse cracking, rutting, ravelling or pothole density, since the same score can be reached by quite different combinations of defects; and the name of the inspector and the date and general weather conditions of the survey, since both affect how visible certain distress is on the day.

Comparability across years depends on segment definitions staying fixed. If the boundaries of a rated section shift from one inspection to the next — a slightly longer or shorter stretch, a different starting point — the resulting scores are no longer describing the same asset, and any apparent change in condition may simply reflect the change in boundaries. Assigning each segment a permanent identifier at the outset, and rating against that same identifier every cycle, is a small step that has an outsized effect on how much later analysis can be trusted. The same applies to keeping the scale applied consistently; a calibration check against reference photographs before each round of inspections helps guard against gradual drift in how the criteria are interpreted.

Once several cycles of comparable data exist for a segment, the shape of the trend becomes more informative than any individual point on it. A slow, steady decline is consistent with normal ageing and can usually be planned for well in advance. A sudden drop across a single cycle is worth investigating on its own terms — it may reflect a genuine distress event, such as a hard winter or a spike in heavy traffic, or it may reflect a change in who was doing the rating or when in the season it was carried out. Distinguishing between those explanations is only possible because the supporting records, not just the score, were kept.

A pavement segment with several years of consistent rating history can be extrapolated forward with reasonable confidence, giving an estimate of when it is likely to cross into a condition band that calls for treatment. Applied across a portfolio, this turns individual inspection records into a forward-looking capital planning tool, flagging which sites are approaching a decision point well before they arrive there, rather than discovering it the year it becomes urgent. That forecasting capability is the return on the record-keeping discipline described above, and it is not available to a programme that treats each inspection as an isolated event rather than one entry in a continuing series.