The Pavement Management System is a means of classifying pavement defects (cracks, ruts, potholes, etc.), recommending methods to rehabilitate the pavement, and prioritizing rehabilitation work according to the seriousness of the defects. Rehabilitation may include one or more of the following strategies:
- Digout and Repair
Soft or broken areas of pavement are excavated to a firm footing and backfilled with compacted asphaltic concrete (blacktop). Our primary means of accomplishing this is by use of a grinder which neatly removes an area needing replacement in a very efficient manner.
- Crack Seal & Chip Seal
Cracks wider than about 3/8" are blown clean and then filled with liquid asphalt. The entire paved surface is then sprayed with liquid asphalt at a rate of approximately 0.4 gallons per square yard and rock chips are spread across the hot liquid asphalt. After pressing the rock chips into the liquid asphalt with a power roller, the liquid asphalt cools to a semi-solid state, retaining the rock chips for a wearing surface. The primary benefit of crack sealing and chip sealing is the prevention of storm water intrusion into the road foundation.
A new layer of asphaltic concrete is placed over the old pavement. The thickness of the new pavement may vary from 1-1/2" to 3-1/2" depending on the amount of additional pavement strength required.
In practice, the development of a pavement management plan is performed in three phases:
Phase I - Field Survey
On an annual basis, paved roads are visually inspected by trained personnel. Roads are divided into sections and the typical defects in each section are recorded. This data is then prepared for entry into the computerized pavement management program.
Phase II - Defect Scoring
The various types of pavement defects (cracks, etc.) are assigned three different levels of seriousness and each level is assigned a numerical score. Thus, a pavement section with widespread alligator cracking and mild rutting might receive a score of 200 points for the cracking and only 40 points for the rutting. Since there are seven different types of pavement defects, each with three levels of seriousness, a detailed analysis can be generated by the system.
Phase III - Rehabilitation Projects
The output from the analysis contains, among other things, a prioritized list of projects for overlays, chip seals, and pavement maintenance work. The list allows county managers to develop a strategy for the annual rehabilitation program depending on the amount of resources available and the amount of time the life of a pavement can be extended by the strategy adopted. For example, managers might weigh the advantages of one mile of overlay costing $100,000 and prolonging the pavement life 15 years against a chip seal costing $15,000 and prolonging the pavement life 5 years. Generally, the amount of money available for the capital improvement budget has a significant effect on the combination of strategies adopted.
The Pavement Management System is an extremely effective management tool. Since its selection of projects is based on hard data, the possibility of biased judgment is reduced. County officials can readily understand the report produced by the system, thereby greatly facilitating their decision making process.
Current Pavement Condition
An analysis of the overall pavement condition of county roads can be performed with the pavement management system and compared to Oregon State Highway Division standards. For 2017 the condition of paved roads in Jackson County was:
- Very Good - 73%
- Good - 21%
- Poor - 5%
- Very Pool - 1%
By conducting yearly condition assessments, county managers can determine whether they are gaining or losing ground in their efforts to provide high quality paved roads to all who use them.