Dennis Polhill

NATIONAL ROAD AND STREET MAINTENANCE
The Third Annual
Road and Street Maintenance Conference
April 20 and 21,1982 Fort Worth, Texas

Sponsored by

U.S. Department of Transportation Federal Highway Administration
Center for Local Government Technology

Oklahoma State University
Texas Transportation Institute
Texas A&M University System

THE CENTER FOR LOCAL GOVERNMENT TECHNOLOGY
A University Extension Program of the
Division of Engineering, Technology and Architecture

PAVEMENT MANAGEMENT
Dennis Polhill, P.E.
Pavement Management Systems (Colorado), Inc.
118 Yank Way, Suite 101
Lakewood, Colorado 80228

INTRODUCTION

• 37% of the interstate highway system has been rated to be in fair or poor condition.
• 53% of the country’s paved roads need immediate attention.
• Repair costs were figured at $225,000,000,000 in 1981.
• Automobiles use 56% more fuel traveling over rough and worn surfaces.
• 16.4 billion gallons of gasoline are wasted annually.
• Rough roads increase vehicle maintenance by 100%. Rough roads increase tire wear by 150%.
• Accidents attributable to obsolete roads cost $8.55 billion in 1979.
• In 12 years from 1967 to 1979 the construction cost index increased at nearly twice the rate of the consumer price index. J `
• In 1979 the State of Colorado decided to assess $92,000,000 to road uses in the form of accidents.
• In 1980 the State of Massachusetts decided to assess $3.6 billion to road users in 1985.
• In 1975 the State of Pennsylvania decided to assess $11 billion to road users iri 1979.
• In 1980 the regional municipality of Ottawa-Carleton, Canada saved road users $10,000,000.

Political considerations often tend to force priorities which do not yield the best possible benefit from the limited public funds available. Most elected officials are committed to making the best decisions on behalf of their constituents. Therefore, we, public managers, must be armed with an adequate amount of proper information when presenting Policy and budget issues to our elected officials.

PAVEMENT MANAGEMENT
Pavement Management is the process of making decsions about pavements. It is a daily activity of agencies ‘esponsibfe for pavements. In the context in which “pave ment management” is used today, it infers utilizing more information in order to make those decisions better.

In pavement, decisions are considered to be made at t*O levels the project level and the network level.

Project Level
Project level analysis is the process of looking intensely at a particular pavement for the purpose of optimizing the rehabilitation strategy being considered for that pavement. Project level analysis is considered an engineering application of pavement management information.

Network Level
Network level analysis is the process of looking at an entire system (or network) of pavements. This is done to answer network-wide questions, such as which projects should be considered for rehabilitation. Network level analysis is considered a management application of pavement management information.

Interaction of Levels
A total pavement management system included both project level analysis, network level analysis and an information exchange back and forth between the two levels.

PROJECT LEVEL ANALYSIS APPLICATIONS
Project level analysis may include consideration of several pavement parameters such as ride quality, skid resistance, rutting, structural capacity. The single parameter considered most is structural capacity. The best way to clarify the definition of project level analysis is through example applications.

Overlay Design
To make the best overlay decision, questions of thickness, type, timing and alternates must be considered. A “too-thin” overlay will result in premature failure and loss of some of the benefit (extension of serviceability) of the overlay. A “too-thick” overlay results in the expenditure of too much money now and in the loss of the option to put those dollars into another needy project. In Denver, a quarter of an inch of A.C. overlay equates to about $8,000 per mile. In Edgewater, Colorado, this type of analysis saved an overlay project $19,500 (see Appendix “A”).

Reconstruction Design
If grades are to remain the same during a reconstruction project, considerations simtlarto an overlay design are in order. “Can the existing structure contribute to or be used in the new structure?” In Frostburg, Maryland, this question was raised (see Appendix “B”). By acquiring proper information the design engineer was able to determine which sections required rebuild and which sections could be rehabilitated. The estimated savings to the project was over $200,000.

Street Widening
If grades are to remain the same during a widening project, considerations similar to the reconstruction design are in order. “Can the existing structure contribute to or be used in the new structure?” or “what needs to be done to the existing pavement to make it serviceable as the center two lanes of the project?” This question was raised during a project in Aurora, Colorado. In the final analysis it was determined that the existing 2 lane roadway would be structurally sufficient with a minor overlay and isolated locations of additional structural padding or patching. The theoretical savings on the project was over $400,000, but the actual design has not progressed enough to calculate a savings based on actual costs and other changes to the project.

Street Acceptance
The same type of analysis can be done on a new street. The obvious application is for acceptance of streets built by developers. We have all seen or heard of cases where as soon as a street is accepted by the mdriicipality, it fails. A draft specification for street acceptance is shown in Appendix “C”. The process merely requires that the street must demonstrate its ability to perform for a period of time as specified by the municipality. Some method of non-destructive testing and professional engineering analysis must be used. This approach will give cities the assurance they need that the facilities they accept will perform up to some minimum.

Assessment of Impacts
Assessment of impacts includes a variety of possible applications of project level pavement management information. How do you determine the amount of permit fees to be charged for an overweight load moving through your jurisdiction? How does the change of a bus route effect a particular street? How do you determine what the load limits should be on your roads? What is the consequence of a major change in traffic volume or traffic configuration? A new development goes in that results in an increase in traffic loading both during and after construction. How much rehabilitation should reasonably be charged to the development and when should the work be scheduled. Timely rehabilitation resulting from assessment of conditions such as these can protect against premature failure of pavement facilities. Project level analysis gives the capability of addressing these issues.

NETWORK LEVEL PROGRAMING
Network level analysis is the process of looking at an entire system (or network) of pavements to answer network-wide questions. Some typical network level questions are:

• What is the current level of service?
• What will happen to the level of service over the next few years if the budget is set at “X”?
• What streets should receive priority consideration for maintenance or rehabilitation?
• What would be the impact of a change in traffic characteristics?
• What maintenance activity is required to get maximum benefit out of monies expanded?

Any of the same pavement parameters measured in project level analysis may be measured for network level analysis: ride quality, skid resistance, rutting, structural ca pacity. Those most typically used are ride quality (which is more commonly termed road roughness), surface distress and structural adequacy. PMS has established network level pavement management systems based on each of these three parameters individually but usually uses a measure of serviceability termed pavement quality index (POI) which uses all three. Roughness, surface distress and structural adequacy are measured, converted to indices (RCI, SDI, SAI respectively), weighted and added to get PQ1.

Serviceability
The serviceability concept was initiated during the AASHO Road Test in 1958. The serviceability concept was an effort to put the perception of the consumer into proper consideration. That is, when a consumer rates a road he does it with a substantially different outlook than an engineer. The consumer evaluates only roughness. Panels of people were used by AASHO to rate several test sections as they were subjected to loading. The ratings were termed present serviceability rating (PSR). PSR was converted to an index (present serviceability index, PSI) through curve fitting in order to reduce evaluation costs, write a performance equation and encourage the development of equipment which would produce the same data as the panel. Figure 1 shows a typical plot of PSI versus time. The equation for this curve is:

Network Programing Criteria
Of course, a jurisdiction can establish any type of criteria or level of service which it desires. For example, skid resistance could be identified as the lone parameter which when it decreases to a certain level would trigger the need for work. Few jurisdictions today have the funds to follow that as a strategy. Most cities and counties are struggling to have sufficient funds to meet immediate maintenance requirements. Capital programs and rehabilitation programs have been gutted due to inflation and budget cuts. In view of the economic factors in play today most jurisdictions are concerned only with maintaining the maximum structural integrity for the minimum amount of money. That means either fixing or preventing potholes. The situation at the local level is desperate.

Surface Distress Surveys
One pavement parameter which is symptomatic of structure is surface distress. Several standardized methods of performing surface distress surveys have been developed. The most common are: Asphalt Institute, Texas Transportation Institute, Army Corps of Engineers and Province of Ontairo. Surface distress surveys are popular arnong cities and counties because they are relatively simple to perform. They can be performed by in-house engineering staff or by local consultants. The information can be used to estimate “now” needs and has limited applications when summarized properly for engineering, maintenance and management.

Rehabilitation Costs
Let’s look at the performance curve again in terms of rehabilitation costs (see Figure 2). It can quickly be seen that rehabilitation costs increase by over 4 times if rehabili tation is deferred only 12% of a pavement’s design life. For typical pavements, 12% amounts to only about 2 years. In view of this fact, deferred rehabilitation is very expensive. Good management dictates that rehabilitationi occur at a time so as to derive the greatest benefit (or extension of serviceability) possible. The problem becomes very complex since each different pavement structure has a different performance curve and on similar structures with similar curves different pavements will be at a different point in their service lives.

An important point can be concluded here. Unless a jurisdiction has all the money for rehabilitation, it is almost certainly a mistake to program rehabilitation on a”vorse first” basis. Maximum benefit cannot be derived from the limited public funds available if an agency binds itself to a “worst-first” programing philosophy.

Maintenance and Rehabilitation
Within the field of pavement management the terms of maintenance and rehabilitation are distinguished Irom each other.

Maintenance
Maintenance is defined as those routine activities necessary to sustain the integrity of the structure. Maintenance activities include: crack sealing, chip sealing and pothole patching.

Rehabilitation
Rehabilitation is defined as activities which restore the structure in whole or in part to the condition which it was in originally. Rehabilitation activities would include: overlay ing, recycling, padding and structural patching. Reconstruction is generally considered to be such a major undertaking that it is classified outside of rehabilitation in a third (capital project) category.

Maintenance and Serviceability
Serviceability is affected if proper maintenance is not performed. Figure 3 is a graph of serviceability versus time with two serviceability curves: with maintenance and with out maintenance. The normal serviceability curve assumes that maintenance will be performed. If maintenance is not performed the structure of the pavement will gradually be affected adversely.

Maintenance Costs and Serviceability
Maintenance costs increase as serviceability declines. Figure 4 illustrates this. This graph shows that as serviceability increases in its rate of decline, maintenance costs increase. The increasing commitment to maintenance tends to extend serviceability but at a higher cost and lower service level than if rehabilitation was performed. This face has been verified by several studies. The most widely known is research done by the Utah Department of Transportation, which was referenced in NCHRP Report #58 (see Figures 5 and 6). For all categories of roadway the least cost strategy was “A”, where the highest service level was sustained. The highest cost was strategy “D” at which rehabilitation was deferred until such point that substantial increases in maintenance activity was required
in response to public pressure to sustain serviceability at a minimum acceptable level. Strategy “D” was their current’, mode of operation.

Network Example
One of the best documented cases of the successful implementation of a network level pavement management system is the Regional Municipality of Ottawa-Carleton, Canada. The transportation director is Michael J.E. Sheflin, P.E., who spoke at this conference last year. In 1980 Ottawa-Carleton’s road budget was 14% less in actual dollars and 43% less in inflated dollars than it was in 1977. At the same time average service level was improved. Sheflin gives credit for this accomplishment to the progressiveness of his council.

SUMMARY
The U.S. is a great country with unlimited potential. However, the element of human nature which makes us take our life style for granted is once again upon us. Just as it was in 1941 when the U.S. was surprised at Pearl Harbor. Just as it was in 1957 when Russia launched the first satelite into orbit. So it is today with our transportation system. The majority of mileage in our highway system is approaching 75% of its original design life in age. The rate of deterioration is increasing rapidly. We as a nation must pool our knowledge and resources to prevent the catastrophe that will result with the deterioration of our highway system. We are all managers of road systems. Your management role carries with it the burden of leadership. How knowledgeable are you of this problem? How significant is this problem within your own jurisdiction?
This is not a problem which any of us can solve alone. Its solution will require the accumulation of more knowledge than currently exists about pavements and the commitment of the proper level of resources at all levels of government.

REFERENCES
1. Hass, R.C.G., and Hudson, W.R., “Pavement Management Systems”, McGraw-Hill, 1978.
2. Tessier G.R., and Haas, R.C.G., “Pavement Management Guide”, Road and Transportation Association of Canada, 1977.
3. Chong, G.J., “Pavement Maintenance Guidelines”, Ontario Ministry of Transportation and Communications, 1980.
4. Chong, G.J., Phang, W.A., and Wrong, G.A., “Manual for Condition Rating of Rigid Pavements”, Ontario Ministry of Transportation and Communications, 1977.
5. Chong, G.J., Pahng, W.A., and Wrong, G.A., “Manual for Condition Rating of Rigid Pavements”, Ontario Ministry of Transportation and Communications, 1977.
6. Eaton, R.A., and Joubert, R.H., “Pothole Primer”, Special Report 81-21; U.S. Army Corps of Engineers, 1981.
7. Kobi, D., “ARAN, An Integrated And Automated Road Inventory Tool”, American Public Works Association, . 1981.
8. Karan, M.A., “Municial Pavement Management System”, University of Waterloo, 1977.
9. Sheflin, M.J.E., “Your Choice: Bad Roads At High Cost Or Good Roads At Low Cost”, Oklahoma State University, 1980.
10. Haas,. R.C.G., “Combining the Priority Programing of Pavement Maintenance and Rehabilitation”, Transportation Research Board, 1982.
11. Yoder, E.J., and Witczak, M.W., “Principles of Pavement Design”, John Wiley and Sons, Inc., 1975.
12. AASHO, “AASHO Interim Guide for Design of Pavement Structures -1972″.
13. Sheflin, M.J.E., “Good Roads Do Cost Less”, Rural and Urban Roads, October, 1980.
14. NCHRP #58 “Consequences of Deferred Maintenance”, Transportation Research Board, 1979.
15. The Road Information Program, ‘The Extent of Road and Bridge Deterioration on Colorado’s Interstate System”, 1981.
16. The Road Information Program, “The Effect of Obsolete Road Design and Engineering on Driving Safety in Colorado”, 1980.