The Township Board will include monies within the FY 2019 budget for use of the so-called “
Prime and Double Chip” method of constructing a surface on gravel roads.
In brief, this treatment entails covering a properly prepared gravel road with a layer of special liquid asphalt called prime, then a layer of small rocks is rolled and embedded in the liquid asphalt and the process is repeated. This process can extend the useful life of low-volume gravel roads that prevents water from penetrating the road surface, improves skid resistance, and suppresses road dust. Typically, an additional layer of a single chip seal should be considered every 5 to 7 years.
The Road Commission recommends that the process only be considered on roads that have a good gravel surface, good drainage, adequate width, and have lower↓ volume commercial and agricultural traffic. In addition, preparation work such as re-graveling, ditching, or other improvements may be necessary before the prime and double chip seal treatment is placed.
The Road Commission notes that they have had a positive experience where the treatment was placed on “
well prepared lower volume and in particular, dead end roads”.
On the negative side, it is important to realize that the thickness of the prime and double chip is only about ½ inch thick (
as compared to 3 inches for bituminous asphalt). Because prime and double chip is relatively “thin”, the maintenance of pothole can be a difficult and time consuming to provide a bonding patch.
With regard to costs, dust control treatment is about $1,750 per mile annually versus about $110,000 per mile for prime and double chip. Prime and double chip cost is about 63 times higher than dust control or, if compared over seven years, the cost is about 9 time higher than dust control. However, this is significantly less than normal bituminous paving.
Once completed, the Township would assume financial responsibility for placing a new layer of prime and chip on the roadways every five to seven years (
i.e., about $50k per mile
).
If you live on a low volume gravel road and would like to establish a special assessment district (
i.e., the Township would pay for 50% and the residents would pay 50%) for the Prime and Double Chip on your roadway, please contact Township Manager Bill Cargo at 616.604.6324 or
bcargo@ght.org.
If the Road Commissions determines that your gravel road is suitable for the Prime and Double Chip, the Township will prepare the necessary petitions and begin the special assessment district process.
