County to investigate pavement preservation treatment options By Joe Naiman

A working group will determine whether new pave­ment preservation treatment options can extend the time until county of San Diego roads need to be repaved.

A 5-0 San Diego County Board of Supervisors vote Sept. 11 directed the county’s Chief Administrative Of­ficer to create a working group comprised of industry associations, public agencies, and county staff to iden­tify innovative and cost-effective pavement preservation treatments which can be used on county roads.

The CAO was directed to return to the Board of Su­pervisors within 180 days with recommendations based on the working group’s findings.

“It is clear to me that there are some really good ideas out there,” said Board of Supervisors chair Kristin Gas­par. “Our goal is to extend the overall life of our roads and achieve smoother, safer roads.”

The county’s Department of Public Works prioritizes road maintenance work through a pavement manage­ment system which incorporates field review, resident and community input, and mechanical data collection to determine which roads are in need of resurfacing.

The condition of a roadway determines the appropri­ate surface treatment; asphalt concrete overlays are used for significantly degraded roads with extensive cracking and potholes while slurry seal treatment is the preferred maintenance for roads with only minor cracking and no significant surface damage as the thin­ner slurry seal surface layer is more cost-effective and extends the pavement life.

In the past the county has used rubberized asphalt concrete for the top layer. “It was too expensive,” said Supervisor Bill Horn.

Although rubberized asphalt concrete is approxi­mately ten percent more expensive than ordinary as­phaltic concrete, the rubberized surface has proven to be more durable than normal asphalt concrete. Over the long term rubberized asphalt concrete decreases noise by four to six decibels, so the benefit is maximized on roads with high traffic volumes which are close to residential streets. The other advantage of rubber­ized asphalt concrete is that it allows former tires to be recycled, and the county’s use of rubberized asphalt concrete has included grant applications to the state Department of Resources Recycling and Recovery to subsidize the cost.