Method of Determining Ratings in the Survey
Several methods of evaluation were considered. It was determined that a simple rating system of Good, Fair, and Poor for eight major features of the Roads would be sufficient.
Four major areas of need were noted for corrective action. These needs were rated as Much, Some and None. A Road Data Sheet was made that had these items with boxes to make check marks and notes when these things were observed. Each Road had a Road sheet completed on it.
The survey was performed by a Professional Engineer making the ratings. Most of the observations were made while driving slowly with some stops for closer observations. The summary of the Road Data Sheets was consolidated into a spreadsheet for easy review. It includes the average of numerous ratings on each Road and notes made. The spreadsheet has the roads in three sections HB, HBW and HBS.
Explanation of Terms
This explanation of terms is specifically written for the Horseshoe Bay windshield survey done by KCE in July of 2004. These definitions are very basic, but will give the reader a basic understanding of the things that the engineer was considering during the survey.
Ride means the quality of the ride down the road at reasonable speeds for that type of road. In residential areas this is usually 30 MPH or less. Bumps caused by pavement deformities, settlement, improperly filled utility cuts, bad patches and low water valves are some things which make the ride less smooth.
Surface refers to the top layer of the road regardless of what is underneath. It is the wearing layer. It must also prevent water from getting into the base. Cracks, damage, deterioration which lets water through the surface are bad and must be corrected as soon as practical.
Base material provides the foundation for the pavement. Today it is usually a graded crushed stone mix that becomes very strong when wetted and compacted properly. This layer of base spreads out the wheel loads of the traffic enough for the soil below to support the loads without compressing or moving to the side. The base works very well when the moisture content is kept constant. If water is allowed to get into the base, it becomes unstable and doesn't support the pavement properly. An indication of this is a base failure resulting in many cracks in the pavement. A pothole is a last stage of a base failure. Crushed stone base material is much less vulnerable to moisture problems than caliche and dirt.
Condition of the pavement edges can be evaluated by how straight the edge looks, how much the shoulder drops off, and pavement failures. Often edge problems occur where traffic drives off the pavement onto the shoulder or unpaved areas. Ruts or holes on this edge catch water and cause base failures. Traffic cutting corners causes problems with edges. Cracking and raggedy pavement edges are usually because of poor base support.
Grass is sometimes a problem with pavements. Lush yards which come right up to the pavement are often kept wet by watering. This water gets into the road base and causes failures. Grass also likes to grow in cracks. Cracked asphalt pavement will often be taken over by grass. This lets water easily get into the base and cause failures. Grass growing thick and catching dirt will allow the shoulder to become much higher than the pavement. This can block drainage off of the road especially at low points.
Drainage is how the water runs off the road area. It should not stand on the pavement, ditches or anywhere for very long. Swift water running across a road is a serious problem. Standing water is also really bad for the road. Any holes or "birdbaths" in pavements should be filled quickly. Ditches are often silted up because of lawns but when they don't drain properly they should be cleaned. Water damage to a road can come from above, below and from the sides. Well shaped and drained roads have less pavement problems.
Utility Cuts
Cuts made in roads to install utilities are common especially in subdivisions which build new houses several years after the Roads were built. In rocky areas rock saws are used to cut the pavement and rock to the depth needed to lay the new line. The road is a good place to run an undergound utility because it is a flat place for the saw and goes where the utility line needs to tie in. Most utility installations involve a bedding material below, along side and above the conduit being installed. However, very few backfills of utility cuts are done properly so that they are flush with the pavement and won't settle. To fix one that is not done right requires digging it out to a reasonable depth, filling and tamping it with stable material at the proper moisture and then putting a layer of asphalt in the top couple of inches. Cement stabilized backfill works well for this.
Seal Cracks
This refers to blowing out the cracks in the pavement and pouring crack sealing compound in them. This cuts off the free water infiltration into the base and subgrade below it keeping the road from having base failures. Even a small crack through the pavement is a potential problem and if ignored will only get worse. Crack sealing is usually done by a contractor with a special heated tank truck and wand that can apply the material and squeegee the cracks. It is a messy operation and with many cracks it takes a lot of sealing material. Sealed cracks are not pretty, but are sure better than open ones. Hot mix pavements often need crack sealing because the layer of asphalt actually breaks and cracks open. Sometimes they are too big to fix with seal coat. Seal coat pavements will often show reflective cracks from broken hot mix layers underneath.
Cut and Patch
Cut and patch is the proper way to repair asphalt pavement irregularities. The limits of the patch are marked and cut with a concrete saw through the pavement well into the base. The old pavement and the unstable base are removed and new base is wetted and tamped back into the patch for several inches. The vertical sides of the patch give the new material horizontal support. The base is trimmed low enough to place a layer of asphalt, either hot or cold mix, flush with the existing pavement. It is compacted and finished smooth. The base material can also be seal coated instead of using asphalt mix.
Seal Coat is a nickname for Surface Treatment which consists of a coat of asphalt covered by small rocks or crushed stone. The asphalt sticks to the existing surface and the rocks stick to the asphalt. After a short time they become a layer which seals all the small cracks sealing out the water. The rock provides a wearing surface which keeps the tire traffic from wearing away the asphalt. Seal coat is an inexpensive way of protecting a Road and prolonging its useful life. It can be placed on top of base material, over old seal coat and on hot mix pavements. It does not look as good as hot mix, but it is also a lot less expensive. Loose rocks are common on new seal coat Roads but they become less of a problem after a few months of traffic. Seal Coat can be one course or two courses.
Rebuild is needed where the base is in such poor condition that it is not worthwhile to continue maintaining the pavement. Poor construction methods, inadequate base material, unstable subgrade and lack of maintenance are some reasons that roads get in this condition. Anything done just on top to make them look good temporarily is not a good investment.
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