Highway agencies are increasingly turning to pavement
preventive maintenance programs. Preventive maintenance slows the rate of
pavement deterioration, essentially delaying the need for pavement
rehabilitation by several years (see Fig. 1). The delay in rehabilitation
needs, combined with the fairly low cost of preventive maintenance treatments,
can result in dramatic cost savings for pavement preservation. Other benefits
of a preventive maintenance program include:
* Higher customer satisfaction with the road network;
* The ability to make better, more informed decisions on an
* The more appropriate use of maintenance techniques;
* Improved pavement conditions over time;
* Increased safety; and
* Reduced overall costs for maintaining the road network.
Although there are significant reported benefits from
preventive maintenance, starting such a program is not a trivial undertaking;
implementation often requires a fundamental shift in the philosophy of the
transportation agency. To a large degree, the challenges agencies face when
initiating these changes are caused by misconceptions about pavement preventive
maintenance. This article addresses seven of the most deadly misconceptions
about pavement preventive maintenance. These misconceptions are deadly because
any one of them is enough to stop a program in its tracks. Therefore, suggestions
for addressing each misconception also are provided, based on the authors'
experiences working with agencies that have been using preventive maintenance
concepts for years as well as agencies that are just beginning to implement
The seven bullets
We can't start a preventive maintenance program until
our backlog is gone.
Any agency that has inadequate funding to address its
pavement rehabilitation and reconstruction needs is faced with the challenge of
a continuously growing backlog of identified, but unfunded, projects. As long
as there are roads that need rehabilitation, agencies find it difficult to move
away from an improvement program that is primarily oriented towards addressing
the worst roads first. This is especially true when the agency is considering
dedicating a portion of its improvement funds to a program that includes the
application of preventive maintenance treatments to roads in good
An effective way to counter this argument is to use a
pavement management system to demonstrate the effect of each improvement
program (one that addresses the worst roads first and the other that includes
rehabilitation and preventive maintenance treatments) on overall network
conditions. Agencies that have used pavement management to demonstrate the
importance of starting a preventive maintenance program to help reduce the size
of an agency's pavement backlog have found that the results take time to be
realized. But, as shown in Fig. 2, eventually a preventive maintenance program
results in dramatically different network conditions because of the reduced
rate in which the backlog grows with preventive maintenance. Since preventive
maintenance treatments are applied to roads in good condition, they remain in
good condition for a longer period of time; thereby reducing the rate at which
the backlog grows while a portion of the program is targeted to addressing
those roads already in a backlogged condition.
We're already using preventive maintenance treatments.
Many agencies report they are already using the types of
treatments normally included in a preventive maintenance program, such as those
* Crack filling or crack sealing;
* Joint resealing;
* Surface treatments such as fog seals, sand seals and chip
* Slurry seals and microsurfacing;
* Thin hot-mix asphalt (HMA) overlays;
* Diamond grinding;
* Joint spall repair;
* Load transfer restoration; and
* Maintenance of drainage facilities.
The key to the use of these treatments as part of a
preventive maintenance program is the early application of the treatment before
major structural deterioration has taken place. In most cases, this means
applying these treatments while the roads are in fairly good condition, instead
of applying the treatment as a corrective treatment until more substantial
treatments can be applied.
For most agencies, the early application of pavement
preventive maintenance treatments represents a marked difference in the way
road networks are managed. Traditionally, most agencies have followed programs
that in which no treatments were applied until rehabilitation or reconstruction
activities were required (after pavement conditions fell below an acceptable
level). Some routine maintenance may have been performed, but the funding for
the maintenance activities was usually unreliable and the highest priority for
funding came from stopgap, or safety, maintenance needs. style="mso-spacerun: yes">
Agencies with preventive maintenance programs in place are
including preventive maintenance treatments as part of a planned strategy to
slow the rate of pavement deterioration, thereby deferring the need for
rehabilitation. It is this early, planned application of the preventive
maintenance treatments that marks one of the primary differences from the way
these treatments have been used in the past.
It can't be cost-effective if you're applying
treatments more frequently.
A preventive maintenance program requires the early
application of treatments, while roads are still in relatively good condition.
Admittedly, the life of a preventive maintenance treatment is not as long as
the expected life of a rehabilitation treatment, so can it still be
cost-effective to apply more frequent treatments without causing increased
disruptions to the traveling public?
The answer is yes.
A life-cycle cost analysis is one way of comparing the costs
associated with maintaining a pavement facility over an analysis period that
includes at least one rehabilitation cycle. An example of this application is
In the first application, represented by strategy A, an
initial treatment is constructed at a cost of $400,000. A minor rehabilitation
treatment is applied in years 8 and 16 at a cost of $80,000 for each
application. Routine maintenance costs associated with this strategy are $500
per year and the salvage value associated with the last application of the year
16 treatment is $40,000 (since half of the life of the treatment is used at the
end of the analysis period, half of the cost of the strategy is considered the
salvage value). The expenditure stream diagram associated with this strategy is
shown in Fig. 3.
Expenditure stream diagram for strategy A.
The second strategy, represented by strategy B, is presented
in Fig. 4. This strategy is comprised of the same initial treatment, with a
$12,000 preventive maintenance treatment applied in years 4, 8, 12 and 16.
Annual maintenance costs associated with this strategy are $800/year and there
is no salvage value since the life of the last treatment is used up at the end
of the analysis period.
Expenditure stream diagram for strategy B.
The present worth values associated with each strategy are
presented below. Both examples are based on a 20-year analysis period and a
discount rate of 4%. The example demonstrates that strategy B, which included
more frequent applications of a lower cost treatment, resulted in a lower
life-cycle cost, and that preventive maintenance treatments can reduce the cost
of preserving the pavement network. The more frequent application of preventive
maintenance treatments typically doesn't interfere with normal traffic
operations because many of the treatments can be applied at night, or during a
relatively short closure.
Present Worth of Strategy A
(routine maintenance) =
(treatment 1) =$ style="mso-spacerun: yes"> 58,455
(treatment 2) =$ style="mso-spacerun: yes"> 42,713
(salvage value) =$
Present Worth of Strategy B
(routine maintenance) =$ style="mso-spacerun: yes"> 10,507
(all four treatments) =$ style="mso-spacerun: yes"> 32,928
(salvage value) =$ style='mso-tab-count:1'> 00
Decision-makers will never support this type of
Once an agency can demonstrate the cost effectiveness of
preventive maintenance to decision-makers, it is easier to convince these
individuals of the benefits associated with such a program. Consider the
following when promoting preventive maintenance program to management:
* Don't oversell the program: Several agencies have
determined that preventive maintenance programs greatly reduce their overall
cost of maintaining a pavement network. However, when reporting the cost
savings to decision-makers, these agencies have been conservative in reporting
the benefits that the agency will realize. As a result, the agencies are much
more confident of their ability to meet their targets.
* Remember that it takes time for the benefits to be
realized: Although some benefits associated with the use of a preventive
maintenance program may be immediate, the improvement in network conditions and
overall reduction in life-cycle costs may take time to be realized by the
agency. For example, it took the Georgia DOT about 15 years to achieve a
"steady state" condition for their pavement network. It is important
that decision-makers understand this so that support for a program is not
suspended before the results are realized.
* Communicate the preventive maintenance concept in terms
that decision-makers can understand: Most of us are familiar with the use of
preventive maintenance concepts in their every day life, from routine visits to
the dentist to maintenance schedules for cars and other vehicles. The
application of these concepts to pavements is very similar. We don't postpone
maintenance on our cars until the engine seizes; why would we apply this
approach to pavement preservation? Communicating the message in a way that
decision-makers can understand helps to secure their support.
* Set goals for the program: An effective preventive
maintenance program should be established with clearly defined, measurable
goals that can be achieved within a stated timeframe. Over time, progress
towards the goal should be monitored and reported to the decision-makers to
continually build support for the program. An example of an effective goal is
to have at least 70% of the pavement network in good condition within a
five-year period. A pavement management system can be used to help establish a
reasonable goal for a preventive maintenance program.
Preventive maintenance is solely the responsibility of the
Although in many agencies placing preventive maintenance
treatments is primarily the responsibility of maintenance crews, a preventive
maintenance program must be supported by individuals at all levels of the
organization to be successful. At the policy level, dedicated funding will
support the preventive maintenance program. At this level, managers can promote
the preventive maintenance philosophy within the organization, support the
program among political factions and provide the resources needed to embrace
the philosophy within the organization.
The preventive maintenance program also must be supported by
design, pavement management, research, planning and programming, and
construction. Designers should consider the effect of pavement designs on
maintenance needs and pavement performance. Pavement management should
incorporate preventive maintenance treatments into the analysis of pavement
maintenance and rehabilitation needs for planning and programming activities.
Research can provide information on the optimal timing of preventive
maintenance treatments based on agency performance studies, and construction
can help ensure that the quality of preventive maintenance treatments is
incorporated into the construction activities. Finally, individuals in planning
and programming functions can help ensure that preventive maintenance
treatments are applied on a timely basis, before too much pavement
deterioration has taken place. In short, preventive maintenance is not the sole
responsibility of maintenance, but represents a paradigm shift within the
agency that must be supported by all.
The public will never understand why we're working on good
Where there is a general mistrust of government and public
employees, having treatments applied to roads in good condition will only
further fuel that feeling. This is especially true if there are still plenty of
roads in poor condition that are not being treated. yes">
Since the public also wants government to be accountable,
perhaps the best way to fend off the anticipated negative public response is to
promote preventive maintenance among civic groups, special interest groups and
the general public through presentations at meetings, press releases and
material placed on the Internet. This is essentially a public relations
campaign. The materials that are used should illustrate the cost-effectiveness
of a preventive maintenance strategy and the resulting benefits in terms of
network conditions, improved safety and better levels of service. As with the
decision-makers, explaining pavement preventive maintenance in terms that the
public understands, such as house or car maintenance, is an effective means of
conveying the agency's philosophy to the community. yes">
Our agency can't afford this type of a program.
In reality, your agency can't afford NOT to consider a
pavement preventive maintenance program as a strategy for preserving its
investment in its transportation assets. Not only have preventive maintenance
programs been shown to reduce the overall cost of preserving the pavement
network, but additional benefits have been realized in terms of improved
safety, better network conditions and higher customer satisfaction. Many
agencies have funded their preventive maintenance programs with new funds
obtained through increased taxes or the reallocation of funds from other sources.
However, several agencies have successfully implemented preventive maintenance
programs without levying additional taxes. Granted, the benefits may come a
little slower without additional funds, but any level of commitment to a
preventive maintenance program will eventually result in benefits to both the
agency and the traveling public.
Preventive maintenance support
The preservation of a pavement network is a challenge to
both public and private transportation agencies. Pavement preservation strategies,
including the use of pavement preventive maintenance treatments, have emerged
in the last few years as a cost-effective means of maintaining the functional
condition of a road network.
To be effective, a pavement preservation program requires a
shift in the operations of most transportation agencies. Instead of using
maintenance funds to address only stopgap measures, funds are allocated to the
construction of preventive maintenance treatments while pavement is still in
relatively good condition. To effectively implement this type of change within
a transportation agency, the benefits of such a program must be demonstrated
using available tools, such as a pavement management system.
Resources are available to assist agencies in implementing a
preventive maintenance program. For example, the Federal Highway
Administration's (FHWA) National Highway Institute (NHI) offers a series of
training courses on pavement preservation activities such as preventive
maintenance. Courses currently available or under development include topics on
the preventive maintenance concept, selecting projects that are good candidates
for preventive maintenance, the construction of quality preventive maintenance
treatments and the integration of preventive maintenance treatments into a
pavement management system. Information on NHI training courses is available at
Other organizations actively promoting the use of preventive
maintenance treatments are supported by a combination of governmental, private and
academic agencies. The Foundation for Pavement Preservation (FP2) is one such
example. Through its website (www.fp2.org) and its support for pavement
preservation forums and conference sessions, FP2 has been an early leader in
providing resources to support agency practices in this area. In conjunction
with the FHWA, the Foundation has recently supported the development of the
National Center for Pavement Preservation at Michigan State University. The
National Center for Pavement Preservation is expected to be involved in
furthering research and training efforts in the area of pavement preservation.
More information on the Center is available through its website at