It has long been espoused that spending $1 at the right time on pavement preservation can save $4 or more in future maintenance or rehabilitation on that same pavement section. Transportation Commissioner Mike Sheflin from Ottawa, Ontario, Canada was one of the first professionals to show data from his pavement management system (PMS) that supports this concept. The shape of the present serviceability rating or present serviceability index curve shows the concept in the figure below.
Pavements are built in very good condition and begin to deteriorate almost immediately due to environment and heavy loads. Even if the pavement is well constructed there may be need for early correction of construction deficiencies.
Once these early trends are tracked in your PMS it is possible to use your pavement performance models to predict the rate of deterioration and future failure time. If the pavement section is preserved with a correct treatment earlier in its life, say in year 5 as shown above, the cost can be minimal ($1 in this example). Since the damage accelerates with time and axle loads, if not corrected the cost to return the pavement to its desired quality or serviceability level (the X line shown above) in year 10 is likely to be $4 or $5 according to this concept and further substantiated many times in other studies. Thus the right treatment at the right time earlier in the life of the pavement can save big money. It is exciting to think of how much better your overall pavement condition could be if each dollar is spent four times more effectively. A good pavement database and good pavement management software, such as AgileAssets® Pavement Analyst™, are needed to help you apply these principals in real practice.
The PMS software also needs to help you determine what treatment to apply when, and where to apply it. For example, applying 1 ½ inch overlay to a badly cracked pavement section in “poor” or even “fair” condition, will look great for maybe a year but will still fail prematurely. It is better to use that money to provide preservation treatments to four miles or more of pavements in fair condition to extend their lives by up to ten years.
The National Center for Pavement Preservation (NCPP) headed by Larry Galehouse is leading the way with FHWA in pavement preservation education. This concept, however, needs to be strongly coupled with good PMS software. The PMS software can provide data-driven answers and help build and apply a proper set of treatment selection decision trees for your agency’s environment and geography. The AgileAssets® Pavement Analyst™ software can help your agency get more out of your road budgets by coupling an advanced pavement management solution with modern pavement preservation concepts.
Written by: Dr. Ronald Hudson on August 28, 2014