Pavement Preservation Examples
Click on the examples below to see the explanation as it relates to pavement preservation.
- Example 1:
The state resurfaced the state road in front of my house recently with a very thin asphalt layer. The surface is now rougher than before the contractor performed the work and it produces a lot of road noise. The roadway before the contractor started work was in good condition. Why did the state waste money on a roadway that was in good condition and with the resulting treatment producing a rougher and noisier roadway?
The work is referred to as microsurfacing. Microsurfacing is a pavement preservation technique which we have utilized across the state since 1993. Roadways selected to receive a microsurfacing application typically are still in good condition (minimal cracking, minor rutting, sound base conditions, etc.) and require minimal attention to maintain at a desirable level. Microsurfacing does produce somewhat of a coarser texture than a normal Hot Mix Overlay, but at the same time provides a much better skid resistance under normal and adverse weather conditions. Over time some of the coarseness/roughness typically diminishes and the ride smoothness improves. A thorough analysis of a roadway’s condition (pavement age, traffic volume, surface deficiencies and etc.) indicates when the application of a preservation treatment would be the most cost effective and best way to protect the initial investment on the roadway. There is a cost savings of approximately 65% as compared to a normal asphalt overlay.
- Example 2:
Last year the state resurfaced a section of roadway which I travel to work each day. The roadway and striping were both in good condition. However, about a week or so ago a contractor was spraying something on the pavement between the lanes. This work resulted in the pavement lines being darkened and the reflectors on the centerline losing their reflectivity. It is a dangerous situation at night and during rainy/foggy conditions.
This work consists of the placement of a pre-qualified longitudinal joint stabilization (LJS) product. The LJS product is a pavement preservation material (pavement rejuvenator) utilized to maintain the integrity of the longitudinal construction joint. With normal traffic and rainfall (typically within 3-4 weeks) the reflectivity of the pavement markings and reflectors return to their original condition.
- Example 3:
The state began work on the state route that I travel each day near my home. TDOT was putting a tar and chip on top of a previously paved roadway. The road is now dangerous with some lose rock. It seems that TDOT is going backwards.
A chip seal treatment is a pavement preservation application utilized to protect and extend the life of an existing pavement. A chip seal is also utilized to mitigate existing cracks. The Department has in the past utilized chip seal treatments in various capacities, but due to recent advancements in the materials (polymer and latex additives) the Department is now attempting to utilize it as a pavement preservation treatment as many other states are also doing. While the initial application is very different from what people are accustomed to, the final completed surface is close in appearance to that of a hot mix asphalt pavement. Currently, the Department considers the use of chip seals on roadways with less than 750 ADT (Average Daily Traffic). There is a cost savings of approximately 70%-80% as compared to a normal asphalt overlay. For roadways with higher ADT’s (1000 or more), often another wearing surface is placed over the chip seal.
- Example 4:
I noticed the other day all these black lines running all over the roadway. This looks terrible and appears slick when it rains. What is this? Why is the state wasting tax payer dollars on this?
The treatment is crack sealing. Crack sealing is a pavement preservation treatment being utilized more frequently over the past few years. Crack sealing is one of (if not the most) cost effective preservation treatments being used by not only the State of Tennessee, but numerous other state DOT’s. Sealing cracks prevents water intrusion into the underlying mixes and base material, hence extending the life of the pavement. Water intrusion into the base material and underlying mixes is one of the most destructive forces that a roadway encounters over its lifetime.