Counties continue to face ever-increasing challenges in providing road networks that meet the transportation needs of commerce and industry while maintaining a reliable and safe system for their county residents. Many of these county roads handle traffic volumes and gross weights in excess of some of the highways maintained by the Texas Department of Transportation (TxDOT).
In the distant past, County Commissioners or their operators merely bladed up material from the “borrow” ditches, or bar ditches, on either side and built up a roadbed. Gravel or other similar materials may have been added and worked into this native soil. While this procedure produced improved roadways, the resulting roadbed was still inadequate to handle increasing traffic on county roads. Through trial and error, many County Commissioners learned that some road materials worked better than others and produced more stable roadbeds. For years they experimented, researched, and exchanged ideas with County Commissioners from other counties, as well as contractors and representatives of the Texas Highway Department, now TxDOT. The result was the development of more complete material specifications, as well as improved methods of construction, which meant more efficient and effective means of creating and maintaining better county roads.
Modern-Day Challenges
Many current county roads were constructed decades ago by the simple process described earlier and are not adequate to handle modern-day traffic. These construction methods have sufficed in the past because county roads generally were used only by cars, pickup trucks, and the occasional trailer taking goods to market or hauling supplies from town.
Currently, County Commissioners face a multitude of severe challenges, some of which include:
Increased Traffic Counts
In addition to the normal residential traffic, many counties are experiencing drivers traveling through their county due to proximity to metropolitan regions or attractions in or near their county. Additionally, some counties are seeing more traffic associated with population growth and increased development within their own county.
Heavy Loads
Much of this increased traffic may be heavier trucks, including overweight loads and oversized loads. These vehicles are generally associated with residential and commercial development, as well as with increased oil field, industrial, and other commercial endeavors.
Unfamiliar Drivers
Industrial and commercial truck drivers, delivery drivers, and other people new to the county or from outside the county do not know the roads like long-time residents. This means signage and traffic control are essential and need more attention by county officials than in the past.
Increased Speeds
Drivers of all vehicles – cars, pickups, service trucks, delivery vans, tractor-trailer rigs, heavy industrial trucks – are in a hurry these days. This makes for more dangerous intersections as well as areas of poor visibility or line-of-sight. These higher speeds, especially combined with heavy loads, can cause considerable damage to the roads and can create hazardous traffic situations.
Weather Conditions
Weather has always made the maintenance and upkeep of county roads difficult, but when catastrophic weather joins with these factors of heavy loads, high speeds, and unfamiliar drivers, County Commissioners are faced with problems far greater than many of their predecessors.
The consequences of these challenges can cause significant damage to the county’s infrastructure, including roads, bridges, culverts, and traffic signs, which can result in the reduction or loss of services on these roads. This is true not only when the damage occurs, but also during repairs and/or rehabilitation of these roadways. In addition, these increases in traffic burdens – vehicle counts and heavier loads – and the associated increases in speeds contribute significantly to a rise in accidents, injuries, and deaths.
County Road Maintenance
The following report addresses the maintenance functions and actions most common among Texas counties, including those with large, medium, or small populations. Basic data was derived from a survey sent to 39 counties who are members of the Texas Association of County Engineers and Road Administrators. Eighteen counties responded (a 46 percent response rate). The survey addressed not only what maintenance activities these counties regularly utilize, but also the criteria they use to prioritize when and where to perform these maintenance functions.
Responses from the following counties were used in this study: Brazoria, Chambers, Dallas, Galveston, Glasscock, Grimes, Guadalupe, Howard, Johnson, Karnes, Kendall, Kerr, Lubbock, McLennan, Reeves, Tarrant, Travis, and Waller.
Study Survey Questions and Responses
These county’s road systems vary in size:
- Five counties are responsible for over 800 miles of roadways.
- Ten counties have 400-800 miles of roads.
- Three counties maintain less than 400 miles each.
The study addresses maintenance issues for asphalt-surfaced roads, which include hot-mix as well as seal coat surfaces:
- Ten of the responding counties have road systems consisting of over 80 percent asphalt-surfaced roads.
- Six counties have between 60 percent and 80 percent asphalt-surfaced roads.
- Two of the respondents’ asphalt-surfaced roads make up less than 40 percent of their county network.
In addition:
- Two of the larger-populated counties use only hot-mix pavements.
- Six counties (medium population) utilize both hot-mix and seal coat surfaces on their roads.
- Ten small-to-medium population counties use only seal coat for their road pavement.
- One of the medium-populated counties also uses a superpave mixture in addition to hot-mix and seal coat.
Maintenance Functions
Pothole and Pavement Edge Patching
Virtually all counties include pothole and edge patching of their asphalt-surfaced pavements in their maintenance program. A number of different materials are used to repair or patch the holes or gaps in the pavements and may include the following:
- Hot-mix asphalt
- Hot-mix cold-laid asphalt (commonly known as cold-mix)
- Limestone Rock Asphalt (LRA)
- Asphaltic concrete patching material (bagged)
- Mixed in-place asphalt emulsion and aggregate (applied using a patch truck)
Hot-mix asphalt makes an excellent patch but must be obtained from a nearby hot-mix plant and must be applied soon after acquisition while it is still hot. These conditions of availability and time constraints make it difficult to schedule and supply the hot-mix to the job site, especially for small patching jobs. Cold-mix produces a very good patch and can be stockpiled for short periods and be taken to the job site as needed.
Limestone Rock Asphalt (LRA) also produces an excellent patch and can be stockpiled, usually for much longer periods than cold-mix. Bagged patching material is similar in many ways to cold-mix and LRA, but since it is packaged in small quantities, it is significantly more expensive by unit weight. With a patching truck, the operator can apply a mixture of asphalt emulsion and aggregate using a pressure hose to make the patch.
Generally, patching with hot-mix, cold-mix, LRA, or bagged patching material is done manually with shovels and rakes after cleaning and preparing the hole in the pavement. After the pothole is cleaned out, it is usually primed or tacked with asphalt emulsion to enhance the adhesion of the patching material to the pavement edges and the underlying base or subgrade. The placement of the patching material is then done using hand tools, or in some cases a motor grader or front-end loader. If a patching truck is used, cleaning, tacking, and placing the patching material is done by the operator using the pressurized hose.
The next step after placing the patching material (hot-mix, cold-mix, LRA, or bagged patching material) is to compact the patch leaving the surface of the patch level with the existing pavement. This can be done with a steel-wheeled or pneumatic roller, or simply with the tires of the dump truck, another truck, or a piece of equipment. It can also be accomplished using a small, hand-operated compactor. When patching with the patching truck, compaction can be accomplished in a similar manner. However, the pressure application of the mixture of asphalt emulsion and aggregate provides some compaction, which is not accomplished when patching by hand. In some low traffic volume roads, this may suffice for compaction.
The survey revealed that all the respondents perform pothole and edge patching on their asphalt-surfaced roads: 89 percent use hot-mix and/or cold-mix, 33 percent utilize bagged patching material, and 22 percent patch with Limestone Rock Asphalt. Many of the counties use more than one of these materials.
Almost three-fourths of the responding counties, or 72 percent, own and utilize a patching truck. However, the vast majority, 89 percent, also patch manually or with a motor grader.
All the counties surveyed compact their patches, and a large majority, 83 percent, tack or prime the cleaned-out holes before patching. Most counties use one or more of several patching options, depending on the location in the county where the work is to be done and the amount of patching they will be doing that day. Ninety-four percent of the respondents use either a self-propelled roller (steel-wheel or pneumatic), walk-behind hand-operated compactor, or simply the wheels of a dump truck or other truck for compaction of the patch. Four counties, or 22 percent, use only truck tires for compaction, and only one county uses only a walk-behind compactor.
Pavement Repair and Replacement
When there is degradation of the pavement surface larger in area than a normal pothole, one repair method is to remove sections of the pavement, usually with a motor grader or loader, and replace it with hot-mix, cold-mix, LRA or a two-course surface treatment. Many times, this is at intersections with other roads, commercial driveways, or residential driveways, which are all designated as intersections in the Texas Transportation Code, Title 6 Roadways, Subtitle C County Roads and Bridges, Chapter 255 County Regulation of Sight Distances. The road surfaces at and around intersections can be damaged as vehicles, especially trucks, are turning, as well as accelerating or decelerating. Braking by these vehicles, again especially trucks, can also adversely affect the pavement surface and structure. Another segment of the county roadways that experience pavement degradation is around curves and turns due to twisting forces exerted during turning of the vehicle tires. This damage can be especially severe in roadway curves and turns that are not banked or superelevated.
Damage can also occur due to poor drainage, especially where water stands on pavement due to a low water crossing or poor maintenance of shoulders, bar ditches, and/or culverts. Constant presence of water on or adjacent to the pavement and its base and subgrade weakens and degrades the pavement structure as well as the pavement surface.
A common maintenance process to repair damaged segments of pavement is to remove sections of the pavement with a motor grader or front-end loader and replace it with hot-mix, cold-mix, LRA, or a two-course surface treatment. Placement is usually done with a motor grader or loader, after which it is compacted with a steel-wheel or pneumatic roller.
Another method, known as full-depth reclamation, is to utilize a road reclaimer, also known as a road recycler or an asphalt grinder, to remove the asphalt pavement and the base, pulverize it, and replace it. This is then recompacted in place. While this operation generally produces excellent repairs, the equipment is quite expensive and beyond the budget of many counties.
The survey revealed that 94 percent of the respondent counties reported using full-depth reclamation, and 78 percent use removal and replacement of the pavement on the existing base. A lot of those using the removal and replacement process utilized recycled asphalt pavement (RAP) in addition to hot-mix.
Asphalt Surface Repair or Rejuvenation
Some of the many methods used by counties to resurface and/or rejuvenate the pavement surface are as follows:
Seal Coat: The most prevalent method of asphalt surface rejuvenation among Texas counties is seal coat or chip seal. This is a surface treatment accomplished by spraying the surface with liquid asphaltic material, spreading graded aggregate on the asphalt, and compacting the aggregate into the layer of asphaltic material.
The asphalt material is either emulsified asphalt or asphaltic concrete. The emulsified asphalts could be modified with polymers or could be a specialty emulsified asphalt with proprietary additives. The asphaltic cement, such as AC-10, could be simply asphaltic cement or could be fortified with tire rubber, such as AC-20 5TR, or with added polymers, such as AC-20XP.
The aggregate generally used in seal coating is graded in accordance with TxDOT’s Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges, such as Types A, B, C, D. It could also be graded and then pre-coated with asphalt, such as Types PA, PB, PC, PD.
The survey indicated that emulsified asphalts are more commonly used than asphalt cement (AC). In fact, 78 percent of the respondents reported that they use emulsions or emulsions with polymers, while 22 percent use only AC, AC with tire rubber, or polymer-added AC. Four of the counties, or 22 percent, seal coat some of their roads with emulsified asphalts and some with asphaltic cements.
Crushed and graded aggregate is used by all the counties surveyed. Thirty-nine percent also use crushed and graded precoated aggregate.
Hot-mix: Two-thirds of the surveyed counties, 67 percent, with higher traffic counts, use hot-mix from a hot-mix batch plant as an overlay on existing asphaltic-surfaced pavements. Ninety-two percent of those overlaying with hot-mix primarily use Type D mix. About half of the hot-mix users also sometimes use Type C or Type B asphalt mixes. As with the aggregate types, these asphalt mixes are also specified in TxDOT’s Standard Specifications for Construction and Maintenance of Highways, Streets, and Bridges.
Micro-surfacing: Three of the higher-populated counties use micro-surfacing on some of their roads.
Liquid Asphalt and Sand Surfacing: Only one county reported they resurface some of their roads with an asphalt/sand mixture, which they use primarily on low-volume residential roads.
Fog Seal: Twenty-two percent of the reporting counties utilize fog seal in their maintenance program.
Crack Sealing: Another surface repair function utilized by TxDOT and by many counties is crack sealing using either hot-applied sealants or cold-applied sealants. Sixty-seven percent of the surveyed counties use hot-applied sealants, and only one of these counties uses both hot-applied and cold-applied sealants. The remaining 33 percent do not perform crack sealing on their roads.
Right of Way Maintenance
Maintaining the edge of the roadway pavement as well as the rest of the right of way is a common function undertaken by almost all counties. These actions help provide a safer environment for the drivers and their vehicles. Some of these practices also extend the life and function of the roadway itself.
All counties perform some basic right of way maintenance, including:
- mowing, 100 percent;
- tree and debris removal, 100 percent; and
- blading or clearing the right of way on either side of the roadway with motor graders and/or ditching excavators, 72 percent.
Additionally, 72 percent use herbicide treatment to control the growth of vegetation adjacent to the pavement since grass can invade the pavement structure and do considerable damage over time.
Many counties, 72 percent, have roadside cleanup programs using volunteers as well as employees to improve the aesthetics of the entire roadway and to remove potentially hazardous items from the right of way adjacent to the roadway.
Traffic Flow & Safety Issues
Traffic control, especially in and around work zones, provides a safe environment for the drivers who use the county’s road network. During maintenance and construction work on the roadways, workers are at a significant risk of injury or death. The following activities help reduce these risks and provide a safe and positive traffic flow around and through maintenance activities. This also results in completing the maintenance work faster.
Striping: In the not-too-distant past, very few counties striped their predominately two-lane roads. However, most counties now have a striping program, whether in-house or by contract. Centerline striping is overwhelmingly the most common activity, at 89 percent. Many counties, especially medium-to-large population counties, are also striping lane lines, 44 percent, and pavement edges, 50 percent. Only two of the surveyed counties, or 11 percent, do not utilize striping in their maintenance program.
Work Zone Traffic Control: In light of higher traffic volumes and speeds, traffic control during maintenance activities has become much more necessary than in the past. Awareness of and usage of the Texas Manual on Uniform Traffic Control Devices (TMUTCD) is also becoming more prevalent with county road departments.
All responding counties operate with some type of plan for traffic control in work zones. The majority, or 72 percent, reported they utilize a formal traffic control plan as proposed and endorsed by the TMUTCD. Cones and barricades are used by all the responding counties whether they have a formal TMUTCD work zone plan or not. Many of these counties utilize flaggers, 83 percent, and some use pilot cars, 33 percent, as part of their work zone traffic control. Only two counties use only their road employees to control traffic during maintenance activities without a formal plan.
Decisions on Performing Maintenance
Evaluation and Assessment
Because of monetary constraints as well as limited equipment and workforce, county officials and employees must make decisions on which projects are undertaken and which ones are postponed. This requires a protocol to evaluate and prioritize the maintenance and repair needs for their road pavements.
Some counties conduct drive-by assessments and assign a simple, qualitative description of the pavement condition of each road or section of road, such as excellent, good, fair, or poor. While this method does not quantify the actual condition of the pavement, it does provide a priority list by comparing the descriptions of each road with those of the other roadways.
A more rational and objective methodology is to employ a quantitative metric to evaluate the structural integrity or lack thereof of the pavement surface. A popular format is called the Pavement Condition Index (PCI) which entails a procedure that creates a numerical score (0-100) reflecting the structural integrity and surface condition of the road. With this method, a score of 100 would indicate an excellent road pavement equal to a newly constructed roadway, and a score of 0 would signify a completely deteriorated or failed pavement.
Of the counties participating in the survey, a little over half, 56 percent, use the simple qualitative evaluation, while the remaining 44 percent utilize a more empirical qualitative system such as PCI.
A concern in the industry is the accuracy of these numerical scores in the PCI or similar programs of evaluation. No system is perfect, but the question is this: What margin of error is acceptable when using one of these systems? The survey asked respondents what margin of error they considered acceptable. The answers showed no real consensus:
- One third, 33 percent, indicated up to 10 percent error would be acceptable.
- One third, 33 percent, said between 10 and 15 percent would be acceptable.
- The final third, 33 percent, said they were unsure about the margin of error.
Relatively new concepts of using Artificial Intelligence (AI) and/or Aerial Imagery to assess and quantify the surface conditions of asphalt pavements are in development, and in some cases are already in use. The counties surveyed were asked if they would consider using these new procedures for evaluating their roads, and 67 percent said they would definitely consider these methods; the remainder indicated they would possibly be interested.
Determination of Needs
The impetus for investigating a possible concern or problem with the pavement on a specific roadway is varied. The counties receive input in the form of complaints or expressions of concern from citizens. Additionally, the county may choose to conduct formal evaluations either by their staff or by hired consultants. These evaluations could utilize PCI or a similar program. Almost all the counties surveyed, 94 percent, consider citizen input, and 89 percent utilize “windshield” assessments by in-house staff to determine a need to investigate and possibly perform maintenance on problem areas of their pavements. Additionally, half of the counties responding, 50 percent, conduct formal evaluations either by their own staff or by consultants. –
Study Survey Questions and Responses
Don Bonifay is an engineering consultant for small West Texas counties, specializing in the area of road construction, road maintenance, drainage and traffic control. He is a Registered Professional Engineer in Texas. He has a B.S. degree in Civil Engineering (1970) and a M.E. degree in Civil Engineering (2025), both from Texas A&M University. Don’s past work experience includes: Ector County Engineer (20 years), Senior Training Specialist for the Texas A&M Engineering Extension Service (TEEX) teaching various traffic, signage and safety training courses to TxDOT, county and city employees throughout the state, and Area Manager of a Highway / Heavy Construction Company. He is a public speaker and has made numerous technical presentations to regional, state and national conferences and workshops, including Texas Association of Counties, Texas County Judges & Commissioners Association (State and Regional Conferences) and Texas Association of County Engineers & Road Administrators.