When properly used to improve surface friction and prevent water penetration, agencies report chip sealing allows them to maintain the most square yards of pavement per dollar spent. Photos: International Slurry Surfacing Association
By consistently devoting budgetary dollars to pavement preservation treatments, such as micro surfacing, agencies can maintain four to five times more lane-miles than if they only focus on rehabilitation.
The International Slurry Surfacing Association (ISSA) has applied a hypothetical cost scenario to the Pavement Condition Index chart developed by the Army Corps of Engineers. In this example, a road that receives three preservation treatments over a 25-year period at $2/square yard will remain in good condition for a total cost of $6/square yard. If the road is left untreated for 11 years and pavement preservation is used as reactive maintenance to preserve the pavement, the cost will be approximately $4/square yard. Waiting this long to apply a treatment generally leads to a deteriorated road-base structure, so the reactive maintenance treatment will only last about four years, when it will require yet another treatment or rehabilitation. In comparison, if nothing is done for 12 or more years, a mill-and-fill (mill and overlay) or full rehabilitation will be required at a cost upwards of $12 to $16/square yard.