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TOWN OF HANCOCK Kurtis J Grassett Telephone 603-525-4087 Maintaining our road network is one of a municipality's most expensive endeavors. We know that a sound roadway infrastructure is vital for the economic and emergency needs of any community. In Hancock we have both paved roads and gravel roads, and each has its own pros and cons. Paved roads are very costly to build. Sufficient traffic volume or appropriate topography are two factors that might justify the initial cost. Gravel roads, when built correctly, can be environmentally advantageous and have a lower initial cost, but they may require more yearly maintenance. What they have in common is that future maintenance costs will be lower if the road is planned and constructed correctly. This paper will focus on paved roads and the different maintenance techniques we can use. It will also look at the different reconstruction methods we may use when our roads have reached the end of their useful life.
All road maintenance can be broken down into 2 categories. Maintenance, which will extend the useful life of the roadway, and re-construction which will produce a new road surface and will start the maintenance cycle over again. Almost all of our roads in Hancock are older roads that that began their existence in the 1700 and 1800's. A handful of town roads were built in the 1900s and I believe the last town road was built in the 1970s, over 30 year ago. The age and construction of our roads does provide some challenges in maintaining these roads. Materials and methods have improved over the years, and we have a much better knowledge of how and why a road fails then we did 20 or 30 years ago. In addition to the freeze and thaw cycles, ageing construction materials, and an increase in the number of vehicles, many vehicles are larger and heavier than they were 30 years ago.
We know that all roads will fail. The life cycle of a road is determined by the amount of traffic, the freeze-thaw cycles, choice of surface material, and the materials and construction of the road base. All will have a bearing on how soon a road will fail. This life cycle is not linear, but all roads will fail over the same basic curve. When we graph the road surfaces life cycle over time, the failure curve drops slowly at first and then accelerates as time goes on. By understanding that all roads will fail, but not all at the same rate, we are able to focus our maintenance dollars at the point that will be the most cost effective over the long term.
Many years ago the school of thought was to treat all paved roads the same way and to treat all gravel roads the same way. Substantial studies have proven that we need to change the way we plan and perform maintenance. Rather than grouping "all paved roads," each road must be treated individually, with maintenance tailored to the unique characteristics of that road.
When we look at each road as an individual asset, we consider its current condition and unique topography, the amount of traffic, the original road base, and the possibility that future development or other influences may impact the road. Analyzing these factors helps us determine why a road is failing and allows us to manage our assets more effectively and in a more cost effective manner.
The maintenance performed on our roads can never bring the road back to brand new condition, but it will extend the life of the road and delay the need for reconstruction for a period of years. We evaluate each maintenance application and track its life expectancy, but even with the best maintenance all roads will deteriorate over time and eventually need reconstruction. This is best illustrated by the graph below.
The chart shows how we eventually hit a point where we are spending maintenance money but are not getting the life cycle return on our investment. Essentially, we are throwing good money after bad. The roads that we have placed on our 10 year road reconstruction plan are at this point. The roads have been well maintained, but over the years a number of factors that have contributed to their deterioration. They are all at the point where it is no longer cost-effective to spend maintenance money on them. We would not get the return on our investment. It is time to reconstruct the roads and start the life cycle again.
The goal of maintenance is to preserve the surface of the roadway, and extend its useful life as far as possible. Water and freezing temperatures are the two worst enemies of a road surface. Water enters the base materials through cracks in the road surface, and freezing temperatures cause the underlying soil and water to freeze and expand. The freeze/thaw cycle is one of the surest ways to get pavement to crack, which in turn lets more water into the base materials. This vicious cycle will deteriorate a paved roadway in a matter of years.
About every 2 years, we survey all of our paved roads so that we can understand what influences have been at work. We look for cracking, heaving, and rutting, as well as large rocks that are being pushed up from below. We rate these different distresses and compare them to previous ratings. This helps us to estimate the rate of failure and allows us to choose the maintenance technique that will give us the biggest return on investment. Our toolbox contains a number of maintenance procedures:
The primary goal of all of these is to extend the time between re-construction cycles by ensuring that the road surface will hold its shape and preventing the infiltration of water through the wear surface. None of these methods will eliminate the cracking of the asphalt; they are only meant to repair the cracks that do appear. The longer we go between repairs, the less effective the repairs are at extending the life of the roadway. At some point in the roads cycle we can see that the repairs are not providing their full useful life. This is the point where we have to make the decision to allow the roadway to pass from the maintenance cycle to the reconstruction cycle.
Our current strategy is to keep the roads which are in good shape well maintained while we work on funding those roads that need reconstruction. Maintenance is part of the budget voted on every year, while reconstruction projects are handled by individual warrant articles. One of the biggest struggles we face is funding the maintenance projects we need in order to minimize the amount of reconstruction dollars we must spend.
There are two sources of funding for our road maintenance program. State Highway Block Grant monies are your gas tax dollars, returned to the municipality by the State of NH. When I build a 5-year maintenance plan, I estimate increases in highway block grant dollars first, but these funds have not increased significantly in recent years. The gas tax has not been changed since 1991 (this has resulted in trying to buy 2011-priced material with 1991 dollars), but an attempt to raise funds available for Highway Block Grants was made in the State's previous 2-year budget by increasing the vehicle registration fee by $30.00. For Hancock, this increase was approximately $10,000 in Highway Block Grant funds in 2011 and 2012. The increase in registration fees may go away in the next state budget, in which case we would see an approximate $10,000 drop in revenue.
Our second funding source is local tax dollars, your local tax dollars. The balance of our maintenance costs is included in 2 line items in the highway budget. Any changes in Highway Block Grant funding have a direct effect on what we need to raise on the local level.
Over the last 10 years, the amount we have received from the Highway Block Grant has increased by only about 25%, while maintenance costs have increased by over 200%. In 2001 asphalt was $39.00 a ton, and in 2010 it cost $79.00 a ton. In 2001, I paid $1.39 a gallon for MC-800(liquid asphalt sealer for sand seal), and in 2010 it was $5.00 a gallon. Most of these increases have come in the last 3 years, as the price of oil and petroleum-based products has become a roller coaster ride. Local funding for Highway maintenance has increased about 89%, but this is less than one-half of the increase in costs.
We have absorbed much of this increase by focusing our maintenance methods. We continually re-evaluate our road structure, spending more time on life cycle costing, and considering all the costs associated with each type of road. In recent years we have studied the cost of gravel versus pavement for wear surfaces. Gravel requires more yearly maintenance, but has a lower cost to construct or to re-construct. Modern gravel surfaces are suitable for relatively flat roads with low traffic volume. They are not suitable for steep grades or heavy traffic volumes, as in these situations the yearly maintenance costs will quickly overshadow the up-front construction costs. As roads come into our reconstruction plan, we are evaluating each to determine the appropriate surface for the long term.
When maintenance methods are no longer cost effective, we look to reconstructing the roadway as the most cost effective, long term solution. There are a variety of road reconstruction techniques available. Again, our goal is to select the repair that will give us the longest life at the most reasonable cost. In making this determination we look very hard at the reason for the existing road failure, the topography, and future development potential along the existing roadway.
While we develop a 5-year road maintenance plan, we are looking ahead for approximately 20 years when we create a reconstruction plan. Documents such as our Master Plan, Tax Maps and Subdivision Regulations are important tools, helping us to forecast future road use and traffic volumes. We also investigate causes for the current roadway failure. This is the time to make improvements to drainage, road bed and topography issues. Not only do we look at the roadway itself, but we also look at the impact of the roadway on abutting landowners. This is our one time to make improvements for everyone using the road.
Reconstruction methods differ from maintenance methods because the goal of reconstruction is to correct and strengthen the base materials and surface in order to minimize future cracking. Re-shaping the roadway will ensure that rain water drains from the roadway and roadbed correctly, minimizing the effect of the water on the integrity of the road. The tools in our re-construction toolbox are:
All of the roads on our ten year re-construction plan have been through the entire process. We have determined that our maintenance methods are no longer providing us the return on investment. Below is an assessment of each road's outstanding features along with possible solutions and their associated costs.
Ledge Road-extremely steep grades, poor base, minimal traffic. This road is built on poor base gravels and has been deteriorating for several years. The base moves unevenly during the freeze-thaw and has severe rutting. We have tried shim and sand seal methods to prolong its life, but have experienced early failure of these methods. Due to the poor base materials this road is not a candidate for a shim to look like pavement or a shim and overlay. I recommend a Full Depth Reclamation with Portland cement so that we can stabilize the base material in order to get the maximum life from our pavement.
FDR with cement $46, 500
Juniper Circle-one section of steep grade, fair to poor base, minimal traffic. This road was built slightly better than Ledge Road, but not by much. It experiences minimal traffic, most of which is passenger vehicle. There is little rutting and minimal movement during the freeze-thaw cycle. This road is a candidate for any of the 3 methods. The decision comes down to how much we wish to invest, and how long we want the repair to last. Eventually this will need FDR with cement.
Shim to look like pavement: $52,900
Shim and overlay: $81,000
FDR with cement: 101,985
Prospect Hill (2nd Juniper Circle to end)- mostly flat, one steep section, the base is poor to fair depending on where you are on the road. Traffic is mostly passenger vehicle but is moderate in volume. The base moves very unevenly, particularly as you get near the end. It appears they were running out of money as they were nearing the end. This is not a candidate for a shim to look like pavement. My experience tells me that a 3 inch overlay will not last its full life, but could be tried and I would expect good results on 70% of the road with very early failure on the other 30%. FDR with Cement is the true fix for this road.
Shim and overlay- $153,200
FDR with Cement- $202,600
Sugarbush Road -mostly flat, base is poor to fair. Traffic is residential with only 8 houses on the road. This base does move unevenly, but not as bad as on top of the hill. A shim to look like pavement might work here, but I would bet that we will not get full life. A shim and overlay would work well, and probably last well with the minimal amount of traffic this road gets.
Shim and overlay $77,433
FDR with Cement $97,561
This road is also a candidate to be put back to gravel. In order to do this we would need to grind the pavement into the existing base, build a good base that includes a fabric layer, and install additional drainage. This method would require yearly expenditures to grade and add chloride, and we would need to add gravel about every 6 to 9 years. I would continue to maintain the hill off Prospect Hill Road as pavement and begin the gravel road at the top of the hill.
Put back to gravel $44,000
Duncan Road-some inclines, mostly straight, heaviest traveled road in town. This road is our busiest road in town. It has seen multiple layers of asphalt and suffers from severe longitudinal cracking as well as movement during the freeze-thaw cycle. Any type of overlay would not last its full life on over 50% of the road due to the reflective cracking that would occur. This road is a candidate for FDR. Due to the base movement and the close proximity to Norway Hill, I would recommend FDR with cement to ensure that the base movement does not take the life out of the new pavement prematurely.
FDR $157,600
FDR with Cement $ 175,200
Middle Road (Vatcher Rd to TL)-mostly flat, curvy, second most traveled road in town. This road suffers from a substandard base and poor drainage. It has been shimmed and paved several times. This road sees its share of truck traffic, although I would say that 80% is passenger vehicles. A shim to look like pavement could be used to buy us some time, but the overall fix for this road is a total rebuild. In this case an FDR with cement is the cheaper option due to the amount of pavement we are able to reduce by stabilizing the base. At this time I would not recommend this for a 3 inch overlay, but I would reevaluate that possibility in a couple of years.
Shim to look like pavement $ 127,600
FDR 248,758
FDR with Cement 246,153
When we look at the cost of reconstructing our roads it becomes easier to understand the importance of maintaining what we have. As stated before, all of our roads will fail eventually. Our goal is to minimize that failure rate as much as possible. When roads do require reconstruction, we should be sure we are selecting the right fix for the type of road and looking toward extending the life cycle of our roads for as long as we can. Financing the construction and maintenance of our roads is increasingly challenged by rising oil prices and the fact that pavement is produced from petroleum-derived products.
I hope this is helps you to understand the process that goes into maintaining our paved roads. I would be happy to answer any questions, or receive any feedback on the outline above.
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