Pavement
 

Preservation
 Compendium II
 

SEPTEMBER 2006 

Archived
d
Table of Contents 


Foreword 3 

It’s a Matter of Economics 

Greg Udelhofen, Asphalt Contractor, February 2006 

5 

Partnering for Pavement Preservation in California 

Focus, January/February 2006 

8 

A Nationwide Boost for Preserving the Highway Infrastructure 

Focus, December 2005 

10 

Pavement Preservation: Techniques for Making Roads Last 

Tom Kuennen, Asphalt, Fall 2005 

12 

Tools for the Pavement Preservation Industry 

Tom Deddens, Asphalt, Fall 2005 

15 

Pavement Preservation Fights for Respect 

Tom Kuennen, Better Roads, September 2005 

18 

Moving from Goal to Reality 

Tom Deddens, Roads & Bridges, August 2005 

27 

Anticipation is Sweet 

Larry Galehouse and John O’Doherty, Roads & Bridges, June 2005 

29 

A Helping Hand in Preserving Our Pavement Investment 

Focus, June 2005 

33 

New Course Offers “How to” for Integrating Pavement Preservation and Pavement Management 

Focus, May 2005 

34 

Making High-Volume Roads Last Longer 

Tom Kuennen, Better Roads, April 2005 

36 

A Giant Leap Forward for Pavement Preservation 

Focus, March 2005 

45 

Preservation Partnership Promotes Preemptive Practice 

Greg Udelhofen, Asphalt Contractor, January 2005 

47 

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DC Streets: Innovation Yields Results 

Focus, December 2004 

50 

Preferential Treatment 

Katie Zimmerman and David Peshkin, Roads & Bridges, June 2004 

52 

Pavement Preservation Resources Offer “How-To” Guidance 

Focus, March 2004 

56 

Resources for a Better Future 

Jim Sorenson, Roads & Bridges, February 2004 

57 

The Seven Stallers 

Katie Zimmerman and David Peshkin, Roads & Bridges, December 2003 

59 

National Center for Pavement Preservation Opens in Michigan 

Focus, November 2003 

65 

Principles of Pavement Preservation 

Larry Galehouse, James S. Moulthrop, and R. Gary Hicks, TR News, September/October 2003 

67 

Preserving Pavements and Budgets 

Susan Massey and Pattie Pool, TR News, September/October 2003 

74 

Looking at Long-Term Results 

Gary Hildebrand and Scott Dmytrow, TR News, September/October 2003 

76 

Protecting Roads in the Desert 

Lita Davis, TR News, September/October 2003 

78 

Research Frontiers in Pavement Preservation 

Roger M. Larson, Larry Scofield, and James B. Sorenson, TR News, September/October 2003 

80 

Investing in the Future of Roads 

Jim Sorenson, Roads & Bridges, August 2003 

84 

When Prevention is the Cure 

Tom Kuennen, Better Roads, June 2003 

86 

FHWA Memorandum on Pavement Preservation Definitions 92 

Resources 96 

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Foreword 

by David R. Geiger, P.E. 

Since the release of the original Pavement Preservation Compendium in September 2003, 

there have been great initiatives taken by the State departments of transportation 

(DOTs), industry, and the Federal Highway Administration (FHWA) to advance the message of pavement preservation as one of several effective asset management tools. Since 

the last publication, FHWA has initiated a national evaluation of pavement preservation 

programs in the State DOTs and FHWA field offices to establish a national baseline to 

gain a uniform perspective on the current condition of this vital area. The message of 

“applying the right treatment to the right road at the right time” is becoming widely 

accepted across the country. 

Even though the philosophy of pavement preservation has shown wide acceptance, 

there are still many challenges to be overcome before pavement preservation becomes 

standard practice. The concept of pavement preservation is at the crossroads. The articles 

and references that are presented in this compendium are a continuation of the activities 

to date. This compendium and other technology sharing materials serve as valuable 

resources for providing insight into advancements in the pavement preservation program 

technology and techniques. For more information, visit the following Web sites: 

FHWA www.fhwa.dot.gov/preservation 

National Center for Pavement Preservation www.pavementpreservation.org 

Foundation for Pavement Preservation www.fp2.org 

David R. Geiger is the Director of FHWA’s Office of Asset Management. 

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It’s a Matter of Economics 

Delaware County’s chip seal program provides most economical 

way to preserve road system with limited budget 

by Greg Udelhofen 

Like many local road agencies, New York’s Delaware 

County Highway Department has a limited budget 

to maintain the 270 centerline miles (two-lane 

roads) under its jurisdiction. According to Wayne D. 

Reynolds P.E., commissioner of Delaware County’s 

Public Works, the highway department addresses 

those limited road dollars by preserving the existing 

system with an annual chip seal program—treating 

a fourth of the roads each year. 

“We do what we can with the resources we have 

available,” says Reynolds. “Most of the roads we’re 

maintaining have a ‘hammer stone’ base and the 

increase in truck traffic and traffic volume has 

taken its toll on those roads.” 

Roads under the county’s jurisdiction range 

from 4 to 7 inches of asphalt covering the large 

stone base. The chip seal program has been a mainstay in the county’s maintenance approach to keep 

those roads in good serviceability. With each application, the county hopes to extend a road’s service 

life another five to six years. 

“We do some crack filling and some hot mix 

overlays, but our primary focus is to continue 

building up the roads with chip seal applications 

(some roads have five or six layers of chip seal),” 

Reynolds says. “In cases where we’re experiencing 

heavy rutting due to the increase in truck volume, 

we T & L (true and level edges and excessive rutting) the road surface first before we apply a new 

chip seal coating.” 

With an annual maintenance budget of approximately $3.4 million ($1.3 million to support its 

own staff, $1.1 million for equipment expenditures 

and $1 million for outside contracts) the county’s 

highway department tries to do as much as it can 

internally. 

“Our staff takes great pride in being very efficient in executing the work that needs to be done,” 

Reynolds says. “We complete our chip seal projects 

each summer within a three- to four-week period 

just after the Fourth of July.” 

In the case of this past summer’s chip seal program, where Vestal Asphalt Inc. provided the emulsion, distributor truck and chip spreader, the county’s crews trucked stone to the various road projects, provided its own traffic control and performed the required rolling after the stone was 

spread over the emulsion. 

“We buy the stone we need in spring and begin 

trucking it to the various sites scheduled for chip 

seal,” says Brian Francisco, general highway supervisor for Delaware County. “We take care of any 

preparation work required, like shoulders and T & 

L work, so that when it’s time to begin applying the 

chip seal we’re able to cover approximately 6 to 7 

centerline miles a day. Our contract (with Vestal on 

the approximate 70 centerline road miles in 2005) 

called for four-tenths of a gallon of oil per square 

yard (application) and 22 pounds of stone per 

square yard. We purchased and hauled 25 pounds 

per square yard in case we needed to increase the 

application based on road conditions.” 

Delaware County’s 2005 $300,000 contract with 

Vestal covered the 394,178 gallons of emulsion 

required, along with the cost of the distributor, chip 

spreader and service to operate those two pieces of 

equipment. Francisco says the county purchased 

the 12,318 tons of pre-tested stone separately from 

the Vestal contract. 

“We’ve been doing it this way for a long time 

and seems to be the best approach in keeping our 

roads in good service,” he says. “For the cost, it’s the 

most economical way to get the job done, and 

the planning and execution of the (chip seal) program allows us to complete the work in about three 

weeks. The system just seems to work out well 

for us.” 

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The chip seal program has been a mainstay in Delaware County’s maintenance approach to keep roads in good serviceability. 

Supplier, Contractor Role 

Vestal Asphalt Inc, which is headquartered at Vestal, 

NY (near Binghamton), produces all grades of liquid asphalt emulsions—rapid setting, medium setting and slow setting—both anionic and cationic. 

The company utilizes these products for road construction services provided to town, county, city 

and village highway departments in central, western and northern New York, as well as northern 

Pennsylvania. 

The company owns a broad selection of road 

construction equipment for chip seal operations, 

microsurfacing, slurry seal, crack filling, cold-mix 

production, cold-mix paving, cold patch products, 

dust control spraying operations (using both calcium chloride and asphalt emulsion dust oil) and full 

depth reclamation road rehabilitation. Vestal conducts business from two upstate locations in central 

New York. 

For its chip seal operation, Vestal operates 20 

asphalt distributors (mostly Bearcat and some 

Etnyre) and five chip spreaders (Bearcat and Etnyre), 

along with several rollers. Vestal has the capabilities 

to provide a turnkey chip seal operation, including 

traffic control, with aggregate trucking subcontracted. However, most customers choose to provide their 

own trucking, compaction and traffic control utilizing their municipal forces and equipment. 

For the Delaware County Bid Specifications, for 

example, Vestal was required to quote prices for all 

grades of liquid emulsion and for various pieces of 

construction equipment (with and without operators) used in asphalt emulsion applications, including: power broom, steel wheel roller, pneumatic tire 

roller, variable width chip spreader, pugmill mixer, 

traveling plant mixer, recycler for full-depth reclamation, chip boxes, and bituminous asphalt paver. 

The county then purchases the needed asphalt 

product and contracts the needed equipment for a 

specific project. The specification did not include 

details of the construction process. Those details are 

worked out between Vestal and the road agency at 

the time of the project. 

In the case of Delaware County awarding a chip 

seal project to Vestal, the contractor assesses the job 

and is allowed to make recommendations to the 

county regarding mix design and application rates. 

For the Delaware County chip seal projects this past 

summer, the county specified the application rates 

for emulsion and stone. Vestal monitored the rates 

and made recommendations for changes in the field 

where road conditions warranted deviations from 

the county’s specified application rates. 

“We’ve been working with Delaware County for 

a long time and we’ve been very flexible in providing the services they want us to provide,” says Peter 

Messmer, technical services engineer for Vestal. 

Messmer, who handles the application and inspec6 

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tions on projects like Delaware County’s chip seal 

program, says Delaware County typically solicits 

bids on the liquid asphalt it needs for targeted projects and then specifies the additional services and 

equipment it would like the winning bid to provide. 

“We try to match our capabilities with their 

needs,” Messmer says. “We can provide as much 

support as needed to complete the project or as little as required based on what they want to do themselves. When we are awarded the bid for the emulsion, the county is receptive to recommendations 

we may offer to successfully execute what they want, 

but we’re always willing to mix and match our services with their own capabilities.” 

In 2005, Vestal produced and applied 750,000 

gallons of emulsion, both cationic rapid set #2 

(CSR2) and anionic rapid set #2 (RS2). 

“In New York, emulsion manufacturers are 

applicators as well, and the key to working with road 

agency customers like Delaware County is having 

the capability to provide all the services they require 

and the flexibility to provide only what they want,” 

Messmer says.”We’ve been very fortunate to have a 

long relationship with Delaware County and that 

relationship has allowed both of us to work together in delivering the right solution for the county’s 

road maintenance needs.” 

Reprinted from the Asphalt Contractor, February 2006. 

With each application, the county hopes to extend a road’s service life another 5 to 6 years. 

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Partnering for Pavement Preservation 

in California 

Pavement preservation is receiving a new level of 

emphasis in California with the formation of the 

Pavement Preservation Task Group (PPTG). Comprised of representatives from the California 

Department of Transportation (Caltrans), local 

government, industry, and the Federal Highway 

Administration (FHWA), the group’s goal is to be 

proactive about promoting pavement preservation 

initiatives. “Pavement preservation is the most costeffective approach,” says Shakir Shatnawi of Caltrans and co-chair of the task group. “Prevention is 

like found money.” 

The PPTG has numerous subtask groups that 

each focus on a different facet of pavement preservation, including education, innovation, recycling, 

strategy selection, binders, microsurfacing and slurry seals, chip seals, thin overlays, crack and joint 

seals, and the integration of pavement preservation 

with pavement management systems. Each of the 

subtask groups is co-chaired by Caltrans and industry representatives. “This is truly a partnership 

where people share expertise and resources and 

everyone is committed to its success,” says Shatnawi. 

The PPTG’s initiatives to date 

range from creating technical 

guides and Web-based training to 

planning for a State pavement 

preservation center. The new Caltrans Maintenance Technical Advisory Guide (MTAG), for example, 

is working with FHWA to develop a Web-based 

training and certification course based on the 

MTAG. This course will be made available to transportation agencies and contractors nationwide. 

Users will be able to tailor the training to their specific needs. The interactive training is expected to 

debut late this spring. 

Caltrans, FHWA, and industry are also developing training courses on various pavement preservation concepts, strategies, and techniques for State, 

county, and city workers. “These courses are aimed 

at pavement workers at all levels, from highly 

trained engineers to maintenance workers without a 

technical background,” says Shatnawi. Some classes 

have already been held, with more scheduled in conjunction with the Southern California Pavement 

Preservation Conference, which will be held April 

25–26, 2006, in Diamond Bar, California. 

Another PPTG initiative is the development of 

warranty specifications for construction projects. 

“With the use of warranties, the contractor takes on 

more of the risk and responsibility of the project, 

guaranteeing its life for a predetermined amount of time,” says 

Shatnawi. Caltrans is currently 

testing the use of warranties with 

standard, prescriptive specifications, as well as those that are 

more performance-based, where 

Caltrans provides the minimum 

specifications and the contractor 

is free to add whatever it feels can 

improve the project. 

“Pavement 

preservation is the 

most cost-effective 

approach. Prevention 

is like found money.” 

is a comprehensive reference 

guide on pavement preservation 

strategies, including materials and 

application requirements, field guidance and troubleshooting, and strategy selection. The final draft 

of the guide is available online at www.dot.ca. 

gov/hq/maint/roadway.htm. In addition, the PPTG 

In the planning stages is the 

development of a west coast pavement preservation 

center. The center would focus on such areas as policy, specifications, field investigations, applied 

research, materials, and training. “This will create a 

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site on the west coast for Western States to share in 

pavement preservation advances and research,” says 

Jason Dietz of FHWA. Additional new pavement 

preservation centers being developed for different 

regions or States include ones in Colorado, Texas, 

and Louisiana. Partners in these efforts include 

Texas A&M University and the Texas Transportation 

Institute and Louisiana State University and the 

Louisiana Transportation Research Center. Iowa 

State University’s Center for Portland Cement Concrete Pavement Technology is also working to 

advance concrete pavement preservation. 

For more information on California’s pavement 

preservation initiatives or the PPTG, contact Shakir 

Shatnawi at Caltrans, 916-227-5706 (email: shakir. 

shatnawi@dot.ca.gov), Jason Dietz at FHWA, 916­

498-5886 (email: jason.dietz@fhwa.dot.gov), or 

PPTG co-chair Gary Hildebrand at SemMaterials, 

916-798-0455 (email: ghildebrand@semgrouplp. 

com). For more information on the MTAG Webbased training, contact Christopher Newman in 

FHWA’s Office of Asset Management, 202-366-2023 

(email: christopher.newman@fhwa.dot.gov). 

Reprinted from Focus, January/February 2006 

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A Nationwide Boost for Preserving the 

Highway Infrastructure 

Since launching its Pavement Preservation Technical Assistance Program earlier this year, the Federal 

Highway Administration’s (FHWA) Office of Asset 

Management has worked with highway agencies 

around the country to evaluate their pavement 

preservation programs and offer assistance in developing and expanding their current practices. “We 

are learning a lot about what is being done at the 

State level, the variety of levels of experience in 

pavement preservation, and the different approaches to preserving highway assets,” says Christopher 

Newman of FHWA. These peer evaluations are 

being carried out by FHWA through a contract with 

the National Center for Pavement Preservation 

(NCPP). 

Pavement preservation is a network level, longterm strategy that enhances pavement performance 

by using a variety of cost-effective surface treatments that extend pavement life. These treatments 

must be carefully selected and must be applied 

before the pavement sustains structural damage. 

The 3- to 4-day reviews have been held to date in 

Alaska, Idaho, Indiana, Kentucky, Louisiana, 

Nebraska, Nevada, New Jersey, New Mexico, and 

Rhode Island. In coordination with each individual 

State, the NCPP staff, together with a representative 

from the State department of transportation and 

local FHWA division office, conducted interviews 

with key highway personnel involved in developing, 

implementing, evaluating, and managing the State’s 

pavement maintenance, evaluation, and preservation programs. These key personnel have included 

materials, design, planning and programming, and 

maintenance staff, as well as senior agency officials. 

The review team has also visited field offices in each 

State. “This peer exchange approach has resulted in 

detailed discussions involving all levels of the 

department, from the director to the maintenance 

technicians. It’s been a very positive process,” notes 

Larry Galehouse of the NCPP. 

FHWA has worked with highway agencies around the country, including New Mexico (pictured above), to evaluate their pavement preservation programs 

and offer assistance in developing and expanding their current practices. 

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Topic areas covered by the review team include: 

• Business process. 

• Program implementation. 

• Project selection. 

• Treatments. 

• Materials. 

• Quality control. 

• Performance monitoring. 

• Pavement management systems. 

• Training. 

• Research. 

• Public/Key decisionmaker/Legislator relations. 

“The review was a very good process that helped 

us to formalize our internal procedures for pavement preservation. We were also able to expand the 

knowledge base of our employees,” says Dean 

Weitzel of the Nevada Department of Transportation. “We’re looking forward to finding out more 

about what other States are doing as FHWA compiles the information from the reviews.” 

“This will give us something to benchmark 

against,” notes Tom Raught of the New Mexico State 

Highway and Transportation Department. “It was 

particularly helpful that the review team visited our 

district offices also, in addition to meeting with 

Headquarters staff.” 

Reports summarizing observations and recommendations will be issued for each review. FHWA 

will also hold a closeout meeting with the participants from each State to discuss the observations 

and suggested enhancements or improvements. 

Comments from the review team will be combined 

with feedback from the States and FHWA division 

offices to identify areas where transportation 

departments can enhance system performance at 

reduced cost.“It’s about maintaining and preserving 

our transportation investment,” says Jim Sorenson 

of FHWA. 

Information gathered during the assessments 

will be used to create a database so that pavement 

preservation practices and trends can be tracked 

nationally. The database will provide a benchmarking tool for sharing best practices, as well as examining variables that can adversely affect pavement 

preservation treatments, such as application timing, 

environmental factors, and traffic loads. 

Ten more State reviews are currently scheduled 

for 2006. “We have also received requests from cities 

and counties for reviews,” says Galehouse. FHWA 

and the Local Technical Assistance Program managers are evaluating various ways to respond to the 

local requests. 

For more information or to schedule a review, 

contact your local FHWA division office or 

Christopher Newman at FHWA, 202-366-2023 

(email: christopher.newman@fhwa.dot.gov). 

Reprinted from Focus, December 2005. 

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Pavement Preservation: 

Techniques for Making Roads Last 

by Tom Kuennen 

Pavement preservation is a planned system of treating pavements at the optimum time to maximize 

their useful life, thus enhancing pavement longevity 

at the lowest cost. 

Typically, pavements perform well under loads 

until a particular point in their life spans, at which 

time they deteriorate precipitously and rapidly to 

failure. Experience shows that spending $1 on pavement preservation before that point eliminates or 

delays spending $6 to $10 dollars on future rehabilitation or reconstruction costs. 

Ideally, pavement preservation can mean maintenance of a pavement even when there is nothing 

apparently wrong with it. “The number one fault of 

agencies is that they wait until a problem develops 

before they address it,” said Larry Galehouse, P.E., 

executive director of the National Center for Pavement Preservation (NCPP) at Michigan State University. “Instead, successful pavement preservation 

demands a pavement that’s not in bad shape to start. 

If the structure is good, we can keep water out of the 

pavement, prevent oxidation of the asphalt, and 

maintain good skid resistance. With pavement 

preservation techniques, we will improve their performance and extend their life.” 

That approach is directly opposed to the politically popular road management method of “worstfirst,” in which scarce maintenance dollars are used 

to provide band-aid repairs to pavements which 

have gone too far and are failing. Soon after repairs 

are made, base or pavement failures are reflected through to the surface and the effort has been 

wasted. 

Strong FHWA Support 

In May 2005, the FHWA came out strongly in support of pavement preservation. “Each highway 

agency faces different challenges in applying pavement preservation treatments and establishing an 

effective preservation program,” said David R. 

Geiger, P.E., director, FHWA Office of Asset Management. “Preservation involves a paradigm shift 

from worst-first to optimum timing. Preservation 

programs must focus on demonstrating benefit, 

securing commitment of top agency management, 

convincing the public, and selecting the right treatment for the right pavement at the right time.” 

According to Tom Deddens of the FHWA’s Construction and System Preservation Team, “The goal 

is to help states assess where they are and provide 

comments and recommendations on what they can 

do to further develop and enhance their pavement 

preservation programs.” Those preventive maintenance treatments include crack sealing, chip seals, 

slurry surfacings and hot mix asphalt (HMA) thin 

overlays that will bolster ride quality, provide surface drainage and friction, and correct surface irregularities. 

Preservation with Asphalt Treatments 

As NCPP’s Galehouse implied, a big part of pavement preservation is keeping water out of pavements, and the water-proofing properties of asphalt 

surface treatments and liquid asphalt mean they 

take top billing in pavement preservation techniques. 

Such pavement preservation practices include 

crack sealing, patching, fog seals (a combination of 

mixing-type emulsion and approximately 50 percent water, used to seal shoulders and patches), rejuvenation (application of a rejuvenator agent in a 

procedure similar to fog sealing), and chip seals 

(surface treatment in which the pavement is sprayed 

with asphalt emulsion and then immediately covered with aggregate and rolled). 

Also included are slurry seals (an application of 

mixing-type asphalt emulsion, sometimes with 

additives, mineral aggregate and proportioned 

12 

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water, mixed and spread on clean pavement free of 

dirt and loose gravel); microsurfacing (polymermodified asphalt emulsion, mineral aggregate, mineral filler, water, and other additives, properly proportioned, mixed, and spread on a pavement); cape 

seals (application of slurry seal to a newly constructed surface treatment or chip seal); and thin 

and ultrathin hot mix asphalt overlays (HMA overlay with one lift of surface course, generally with a 

thickness of 1.5 in. or less). 

Three varieties of liquid asphalts are used in conventional surface treatments: 

•	 Liquid asphalt cement is used to construct chip 

seals in regions that have very hot weather. The 

asphalt cement is shot at high temperatures 

where it flows well and accepts chips readily. A 

fairly warm pavement surface is required so the 

asphalt does not cool off too quickly before 

placement of the chips. 

•	 Cutback asphalts are blends of asphalt cement 

with solvents, which make the asphalt cement 

fluid for spraying or mixing. The solvents then 

evaporate, leaving the base asphalt cement in 

place to bind the rock. Solvents used include 

gasoline for rapid-curing, kerosene for mediumcuring, and diesel fuel for slow-curing cutbacks. 

The use of cutback asphalts, once common for 

chip seals, has declined considerably because of 

environmental restrictions on hydrocarbon 

emissions from evaporating solvents in specific 

regions around the county. 

•	 Emulsified asphalts are an emulsion of very small 

asphalt cement particles held in suspension in 

water with the use of an emulsifying agent. Like 

cutback asphalts, emulsified asphalts come in rapid-, medium-, and slow-setting grades for different uses. The various grades are developed 

through the use of different emulsifying agents 

and the addition of some solvents. These asphalt 

particles are either anionic (negatively charged) 

or cationic (positively charged). 

The rapid-setting emulsions are used mostly for 

chip sealing, while the medium and slow setting 

grades are used for emulsion mixes or recycling and 

fog or tack seals. The emulsified asphalt ‘sets’ or 

‘breaks’ when the asphalt particles precipitate or fall 

out of the water suspension and coat the aggregates. 

The emulsion changes color from brown to black 

during this process. 

Ever Popular Chip Seals 

Chip seals have been used for decades to preserve 

riding surfaces. A chip seal is a surface treatment in 

which the pavement is sprayed with asphalt and 

then immediately covered with aggregate and 

rolled. Chip seals are used primarily to seal a pavement with non-load-associated cracks, and to 

improve surface friction. They also are common as 

a wearing course on low volume roads. 

The asphalt binder can be modified with a blend 

of ground tire or latex rubber, or polymer modifiers, to enhance the elasticity and adhesion characteristics of the binder. A variant of the chip seal is 

the fog seal, a light application of slow-setting 

asphalt emulsion diluted with water, and without 

the addition of any aggregate applied to the surface 

of an asphalt pavement. Fog seals are used to renew 

aged asphalt surfaces, seal small cracks and surface 

voids, or adjust the quality of binder in newly 

applied chip seals. 

A cape seal is a combination of a chip seal and a 

slurry surfacing or seal. For paved roads, the chip 

seal is applied first and, between four and 10 days 

later, the slurry seal is applied. For unsurfaced roads, 

an application of MC-70 or SC-70 cutback asphalt 

is applied first as a prime coat, followed about two 

days later by a chip seal and about two weeks later 

by a slurry seal. 

Joints, Cracks and Potholes 

In advance of any surface treatment, pavements are 

prepared by sweeping and sealing the joints and 

cracks. “It is critical that all necessary preparation 

work such as crack filling, pothole repair, patching, 

leveling, and dig-outs be done prior to surface treatments being placed,” reports the California Department of Transportation (Caltrans). 

Caltrans says crack filling and sealing is its first 

line of defense in roadway maintenance. Caltrans 

urges that cracks 1/4 inch or wide be filled or sealed 

before rainy seasons or before the application of 

maintenance surface treatments such as fog seals, 

sand seals, slurry seals, chip seals or maintenance 

overlays. 

Potholes are bowl-shaped holes of various sizes 

which are associated with pavement fatigue and 

poor drainage. Highway departments can minimize 

potholes by keeping water out of the base material. 

Water weakens pavement support and contributes 

to frost heave and cracking. 

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A long-term study that began under the Strategic 

Highway Research Program, and continued under 

FHWA’s Long-term Pavement Preservation program, found that for patching potholes, quality of 

materials is more important than method or 

machine. The use of quality, even premium, materials is the utmost variable in effective pothole patching. The throw-and-roll technique proved as effective as the semipermanent procedure in most situations and is more cost-effective, making it a good 

choice, so long as quality materials are used. 

Rejuvenating Pavements 

Pavement rejuvenators are applied to existing aged 

or oxidized HMA pavements in order to restore 

pavement surface flexibility and to retard block 

cracking. Emulsified sealers, binders and rejuvenators are used in pavement preservation to protect 

oxidized asphalt surfaces or actually penetrate and 

rejuvenate them. 

The oxidative aging of pavements begins at the 

time of construction and continues throughout a 

pavement’s life. However, most aging occurs within 

the first two to four years of service life. This results 

in the top half-inch or so of the pavement surface 

becoming more brittle than the underlying material due to the actions of water and environment. This 

can result in raveling and/or premature cracking, 

which begins at the pavement surface. 

Rejuvenators are formulated to penetrate into 

the pavement and then enhance the properties of 

the asphalt binder of the existing pavement. These 

treatments are most commonly used in the western 

states where ultraviolet exposure appears to promote greater oxidation. Treatments can begin 

immediately after construction but more typically 

occur many years later when some form of distress 

is observed. 

Slurry Surfacings 

A slurry surfacing, also known as a slurry seal, is not 

the same as a chip seal. Instead, it is a mixture of 

aggregates dispersed in an asphalt emulsion and 

applied in a slurry state. It is usually a mix of polymer-modified emulsion and fine crushed aggregate 

that is spread simultaneously in one pass over the 

street at a particular thickness. The slurry cures as 

the water evaporates, leaving only the asphalt to 

coat the aggregate. 

Slurry surfacings are designed in a lab, are proportioned by a slurry machine, and laid down and 

cured so the asphalt-to-aggregate ratio is maintained at the optimum value to assure uniform 

aggregate coating and adhesion. Such friction 

courses use very large fractions of fine material, giving a very high surface area and a lot of microstructure, leading to a sandpaper surface and a high skid 

resistance while maintaining a smooth finish. 

A variant of the slurry surfacing is microsurfacing, which is a mix of polymer-modified asphalt 

emulsion, mineral aggregate, mineral filler, water, 

and other additives, which is proportioned, mixed, 

and spread on a paved surface. Microsurfacing differs from slurry seal in that it can be used on high 

volume roadways to correct wheel path rutting and 

provide a skid-resistant pavement surface. 

HMA as a Preservation Treatment 

For severely distressed surfaces, thin HMA overlays 

will provide a like-new surface, prolong pavement 

structure life, and make a pavement stronger for 

only an incrementally higher expenditure than 

competing surface treatments like chip seals or slurry surfacings. 

For many roads and streets the best preventive 

maintenance strategy may be a thin HMA overlay. 

This thin (0.5 to 1.5 inch) surfacing combines the 

best attributes of HMA’s strength and smoothness 

with a low cost that makes maintenance dollars go 

farther. Aesthetically, the overall impression is of a 

brand-new road, at the price of a thin overlay. Other 

benefits include HMA’s trademark quiet pavement 

and smooth ride. 

Tom Kuennen is principal of ExpresswaysOnline.com, 

Buffalo Grove, Illinois. 

Reprinted from Asphalt, Fall 2005. 

14 

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Tools for the Pavement Preservation Industry 

by Tom Deddens, P.E. 

Over the years, the Federal Highway Administration 

(FHWA) has changed its emphasis from construction to preservation of the National Highway System (NHS). FHWA is now providing assistance to 

the state DOTs and the highway industry through a 

number of new programs. 

History 

Historically, preventive maintenance activities have 

been excluded from federal-aid funding. When 

President Eisenhower initiated the construction of 

the Interstate System in 1956, he left the maintenance responsibility of the newly constructed roadway system squarely on the shoulders of the individual state transportation agencies. As the interstate system aged, Congress initiated the 4R Program (resurfacing, restoration, rehabilitation and 

reconstruction) which funded the activities to 

maintain the serviceability of the Interstate system. 

The passage of the Intermodal Surface Transportation Efficiency Act of 1991 created the Interstate 

Maintenance program and provided funds using 

the existing 4R equation. A 1993 FHWA memorandum identified any work which provided additional structural capacity, prevented the intrusion of 

water into the pavement, or any other work that 

extended the life of the highway, as being eligible for 

federal funding. 

A 1998 memorandum gave state DOTs more 

flexibility in managing their federal-aid highway 

program. This memorandum permitted the use of 

“planned staged construction” for the completion of 

surface paving independent of other required project modifications. The memorandum simultaneously placed added emphasis on transportation systems preservation and encouraged the state DOTs to 

properly fund preservation programs without any 

additional federal assistance. 

New Definition 

In October of 2004, a memorandum issued by the 

Office of Infrastructure now makes preventive 

maintenance activities eligible for federal-aid funding based on a definition of pavement preservation 

which was consistent with the AASHTO definition: 

“...The planned strategy of cost effective treatments 

to an existing roadway system and its appurtances 

that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system without increasing structural 

capacity.” 

The memorandum explains that “...projects that 

address deficiencies in the pavement structure or 

increase the capacity of the facility are not considered preventive maintenance and should be 

designed using appropriate 3R standards. Functionally, federal-aid eligibility preventive maintenance 

activities are those that address aging, oxidation, 

surface deterioration and normal wear and tear 

from day-to-day performance and environmental 

conditions.” 

FHWA now accepts that pavement preservation 

is a proactive, long-term strategy to improve pavement performance through a variety of cost effective, thin surface treatments that extend the life of a 

road, such as crack and joint sealing, chip seals, slurry seals, microsurfacing and thins and ultrathin hot 

mix asphalt overlays for flexible pavements, and 

partial and full depth repairs, dowel bar retrofits, 

and surface grindings of rigid pavements. To be 

effective, these treatments must be selected carefully and applied before the pavement sustains any 

structural damage. 

Available Resources 

The FHWA’s shift to an emphasis on preservation 

15 

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motivated the Office of Asset Management to reach 

out to the state DOTs and the highway industry 

through a number of activities. The available 

research and “conventional wisdom” was previously 

collected and assembled in a “toolbox” by the Foundation for Pavement Preservation (FP2). The Foundation collected its industry members’ technical 

manuals, brochures, and pamphlets that described 

the “best practices” for the various preservation 

techniques. About this time, FHWA and FP2 produced two videos addressing pavement preservation 

entitled: Protecting Our Pavement: Preventive Maintenance and Preventive Maintenance: Project Selection. The content of these videos were consolidated 

later onto a single DVD. 

Next, a Compendium on Pavement Preservation 

was compiled and is presently available on the 

FHWA’s Pavement Preservation website, www.fhwa. 

dot.gov/preservation/. In 2003, a sequel to the toolbox entitled Pavement Preservation State of the Practice Volume 2 was produced and distributed on CD 

by FP2. 

Due to the popularity of these resources, all the 

information was compiled on a CD, which is now 

available from the Foundation for Pavement Preservation. 

Training Efforts 

Training is another significant part of this transition. Four courses specifically addressing pavement 

preservation issues have been developed and are available through the National Highway Institute 

(NHI). 

131054A Pavement Preservation: The Preventive 

Maintenance Concept 

131058A Pavement Preservation: Selecting 

Pavements for Preventive Maintenance 

131103A Pavement Preservation: Design & 

Construction of Quality Preventive 

Maintenance Treatments 

131104A Pavement Preservation: Integrating 

Pavement Preservation Practices 

& Pavement Management 

A listing of these courses can be found on the 

NHI’s website, www.nhi.fhwa.dot.gov/coursec.asp, 

under Pavements and Materials. 

Interactive Manual 

The FHWA’s Office of Asset Management and the 

Pavement Preservation Expert Task Group are in the 

process of developing an interactive, online version 

of a manual originally developed by the California 

Department of Transportation entitled Maintenance Technical Advisory Guide (MTAG). The training will include modules on crack sealing, patching 

and edge repairs, chip seals, slurry seals, microseals, 

ultrathin bonded asphalt overlays, and thin overlays. When this project is complete in January 2006, 

an individual requiring training will be able to 

access the specific technique at his convenience. 

Modules will be taught by referring the students 

to the corresponding section of the MTAG. Upon 

completing a module, the student will be tested on 

his understanding of the subject material. A pass or 

fail grade will be issued based on the test scores. If 

the student passes, a verification notice will be 

issued to his employer. If the student fails, he will be 

instructed to retake the module and repeat the test. 

National Center for Pavement Preservation 

In August of 2004, the National Center for Pavement Preservation (NCPP) was created through the 

partnership of the FHWA, private industry and 

Michigan State University (MSU). The purposes of 

the NCPP are to: 

•	 Provide technical training related to pavement 

preservation and management 

•	 Reach out to state agencies and provide assistance in development of specifications and be a repository for technical research related to pavement preservation issues 

•	 Coordinate the research activities of regional or 

national pooled-fund studies and those research 

activities undertaken by other regional pavement 

preservation centers as they develop. 

The website of the NCPP is www. 

pavementpreservation.org. Presently the NCPP is 

available to teach two courses, Chip Seal Design and 

Pavement Preservation: Applied Asset Management. 

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Voluntary Assessment Program	 

The most recent FHWA activity is directed toward 

assisting the states by providing a voluntary assessment of an agency’s pavement preservation program. This assessment program is 

being implemented through a 

contract between the FHWA 

Office of Asset Management and The preventive 

maintenance program 

is intended to 

complement 

expenditures 

made for capital 

improvements by 

providing a strategy 

to cost effectively 

prolong the life of 

pavement systems 

of the National 

Highway System. 

the NCPP. Representatives from 

NCPP and/or FHWA will meet 

with the various components of a 

highway agency—upper management, contract administration, 

asset management, maintenance, 

materials and construction— 

involved with implementation of 

maintenance of the roadway system. 

The assessments will be guided 

by a set of standard questions 

regarding the implementation of 

pavement preservation practices 

and policies within that state. A 

report will then be prepared based 

on the responses to these standard 

questions. The report will also 

include general suggestions for improvement, in 

particular, noting the best practices effectively used 

in other states. The information obtained from this 

study will be compiled and placed in a large database that can be accessed by the agencies. Each 

agency will be assigned a unique identifier that will	 

permit anonymous viewing of the data for purposes of comparison with their peer agencies. 

Conclusion 

Interpretations of the various FHWA memorandums can lead to significant differences in the manner in which programs are administered among the 

various agencies. In order to mitigate some confusion, the FHWA 

has just finalized a document 

standardizing the use of the various categories of roadway maintenance. It is FHWA’s intent to have 

this “Definitions Statement” 

endorsed by the AASHTO’s 

Standing Committee on Construction. 

The intent of all this activity is 

to firmly establish pavement 

preservation as those activities 

focusing on maintenance of functional surface characteristics of a 

pavement. The preventive maintenance program is intended to 

complement expenditures made 

for capital improvements by providing a strategy to cost effectively prolong the life of pavement 

systems of the National Highway 

System. As the mantra says, pavement preservation 

is about placing the right treatment on the right 

pavement at the right time. 

Tom Deddens is the Pavement Preservation and Construction 

Engineer in FHWA’s Office of Asset Management. 

Reprinted from Asphalt, Fall 2005. 

*The FHWA contact for current information on this topic is 

Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

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Pavement Preservation Fights for Respect 

by Tom Kuennen 

Six years after the creation of the Office of Asset 

Management within the Federal Highway Administration, 13 years after the establishment of the 

Foundation for Pavement Preservation, and two 

years after the founding of the National Center for 

Pavement Preservation, the concept of pavement 

preservation still faces a tough climb to full acceptance. 

While many county and city road agencies maintain pavement inventories and pavement management systems, not all have been able to integrate the 

pavement management system with a preservation 

program that will show where dollars will be best 

spent toward riding surface longevity. 

Classic pavement preservation starts with a pavement inventory and condition database, which is 

used to establish which road surfaces are near the 

point at which they will begin to fail rapidly. Those 

pavements—not the worst pavements favored by 

politicians—are the ones that should be targeted 

with whatever funds are available, prolonging their 

service life to a degree not possible otherwise. 

But a problem arises for the road manager. To 

spend money where it will do the most good, pavements that are falling apart should not receive 

maintenance dollars, but should be allowed to fail 

and then be rebuilt. That’s why adhering to a pavement preservation program may put a road administrator in conflict with elected officials, who may 

demand quick fixes for failing pavements. 

At that point, the pavement inventory and pavement management system can be exhibited to show 

that the road administrator is doing the right thing. 

The inventory and PMS provide cover for both the 

administrator and elected official in supporting 

pavement preservation principles. 

“The worst way of responding to complaints is 

the policy of worst-first,” said John O’Doherty, P.E., 

training coordinator, National Center for Pavement 

Preservation. “It’s a suboptimal strategy and, if you 

continue to follow it, you’ll eventually bankrupt 

your agency. When you wait for worst-first, you’ve 

waited until structural damage is being done to the 

road and you have to do major rehabilitation. 

Worst-first waits until serious damage is done, and 

every road in your system will have to descend to 

that level, making it the most expensive strategy you 

can think of.” 

Worst-first is seductive politically, though, O’Doherty told Better Roads. “It’s very appealing politically,” he said. “If you’re an elected official, or 

department director, it’s reassuring to the public to 

have them hear that you are doing the worst roads 

first, because they will get a warm, fuzzy feeling. But 

it’s a terrible policy.” 

Agencies differ 

“Each highway agency faces different challenges in 

applying pavement preservation treatments and 

establishing an effective preservation program,” said 

David R. Geiger, P.E., director, FHWA Office of 

Asset Management, in a May 2005 memo promoting pavement preservation. “Preservation involves a 

paradigm shift from worst-first to optimum timing. 

Preservation programs must focus on demonstrating benefit, securing commitment of top agency 

management, convincing the public, and selecting 

the right treatment for the right pavement at the 

right time.” 

Those preventive maintenance treatments 

include crack sealing, fog seals, chip seals, thin coldmix seals, surface recycling, and hot-mix asphalt 

thin overlays, including dense-, open-, and gapgraded mixes that will bolster ride quality, provide 

surface drainage and friction, and correct surface 

irregularities. 

Many road agencies that are wedded to existing 

practice—ranging from old-fashioned cities in 

which an alderman or councilman decides where 

18 

Archived
the road funds are spent, to state DOTs where highway building and rebuilding take utmost priority— 

are disinterested or ambivalent regarding programmed pavement preservation, especially when it 

means shifting funds from favored programs, and 

there is no central authority to compel them to do 

otherwise. 

Some states have implemented pavement preservation programs. Under a new FHWA program in 

2005, the National Center for Pavement Preservation is reaching out to those state agencies that will 

cooperate to gauge the depth of pavement preservation in their agencies. 

Mega-municipalities such as Los Angeles, down 

to small townships like Minisink, N.Y. have adopted 

pavement preservation programs. And new types of 

governments that merge city with county have 

embraced pavement preservation, such as the Metropolitan Government of Nashville & Davidson 

County (Metro Nashville). 

One might say that pavement management + 

pavement maintenance = pavement preservation. 

The pavement preservation community is pulling 

out all stops to bridge that crucial gap where pavement management systems and inventories meet 

with maintenance activities in the field. 

Too often, maintenance is not driven by pavement management, said Katie Zimmerman, P.E., 

Applied Pavement Technology, in a presentation at 

the 2003 Transportation Research Board meeting in 

Washington, D.C. In the presentation Integrating 

Preventive Maintenance Into Pavement Management 

Systems, co-authored by David Peshkin, P.E., also of 

APTech, Zimmerman said that, traditionally, the 

highest priority is given to correct safety deficiencies. “Treatments are triggered when a pavement 

section falls below an acceptable level,” she said. 

“Funding for routine maintenance is typically unreliable, so treatment application cycles vary.” 

Turf wars within an agency can choke pavement 

preservation. “Maintenance and rehabilitation are 

often programmed by different groups within the 

highway agency,” Zimmerman told TRB. “Maintenance activities are frequently not reported in 

accordance with a referencing system used by pavement management. The same maintenance treatment can be used as a preventive, corrective, or 

stop-gap treatment.” 

But more recently, road agencies are beginning to 

integrate preventive maintenance into planning and 

design activities, reducing the life-cycle cost of preserving a pavement through the use of preventive 

maintenance. Through planned, early application of 

preventive maintenance treatments, good roads are kept in good condition, validating the motto of 

pavement preservation being “the right treatment 

for the right road at the right time.” 

Last year, an analysis by Midwest Regional University Transportation Center, University of Wisconsin-Madison, concluded that most state agencies 

are ambivalent to the pavement preservation message because of sheer inertia. 

“The preventive maintenance philosophy is 

somewhat contrary to that of traditional public 

administration for primarily two reasons,” MRUTC 

said, as reported in Better Roads (April 2005, Making High-Volume Roads Last Longer). “First, it 

requires strategic rather than operational analysis 

on the part of agency managers and elected officials. 

That is, the benefits of preventive maintenance, 

which are best expressed in terms of future value, 

are intrinsically undervalued by management concerned with current operating costs.” 

Demonstrations of long-range savings can help 

alter attitudes, but it’s difficult, the center said. 

“Although life-cycle cost analysis and other techniques have made progress toward overcoming this 

difference in cost-benefit perceptions, the operational mode of thought stands in the way of broader preventive maintenance implementation.” 

The benefits of integrating preventive maintenance with a pavement management system were 

described in a 2005 TRB presentation, Potential 

Benefits of Integrating Preventive Maintenance into 

New Jersey Pavement Management System, by Helali, 

Bekheet, Jackson, Jumikis, and Zaghloul. 

The New Jersey Department of Transportation 

established a pavement preservation strategy that 

emphasizes preventive maintenance and moves 

away from the worst-first approach, they wrote. “To 

be able to implement the PM program and show its 

benefits and the merits over the existing worst-first 

approach, NJ DOT decided to integrate the PM program into [its] PMS.” 

The proposed PM program consists of two components, one short-term and one long-term. “The 

short-term component involves an annual crack 

sealing/filling program, and addresses the current 

needs of the network,” the authors said. A long-term 

component involves staged treatments, in which the 

rehabilitation and PM treatments are combined and 

integrated in the form of a long-term preservation 

program, perhaps over two decades. The final product would be a multi-year maintenance and rehabil19 

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itation program for the entire network, which is NCPP charged with outreach 

based on economic analysis and optimization. 

New initiative for states 

To jump-start recognition of pavement preservation, the FHWA’s Office of Asset Management has 

recently launched a Pavement Preservation Technical Assistance Program to help highway agencies 

define their pavement preservation programs, and 

to build a pavement preservation database. 

The National Center for Pavement Preservation 

at Michigan State University in East Lansing, Michigan, is coordinating with individual states and the 

local FHWA division offices to conduct interviews to 

discuss procedures, policies, and programs associated with pavement preservation. “The goal is to help 

states assess where they are and provide comments 

and recommendations on what they can do to further develop and enhance their pavement preservation programs,” said Tom Deddens of the FHWA’s 

Construction and System Preservation Team. 

“Over the next two years, the FHWA Office of 

Asset Management will lead an effort to conduct a 

series of comprehensive technical reviews and evaluations of DOTs’ pavement preservation programs 

at the request of individual states,” said FHWA’s 

Geiger. “For each appraisal, we will conduct approximately 80 hours of program review and interviews 

of key personnel and provide both an oral closeout 

and a written report highlighting strengths, identifying gaps, and making recommendations for 

improvement of that DOT’s program. The contract 

will consist of a maximum of 10 such reviews during the first year, with the likelihood that the effort 

will be extended by 10 more such reviews in FY 

2006.” 

Pavement preservation is a powerful tool 

through which any highway agency can improve 

pavement condition and significantly prolong its 

life within existing budgets, Geiger told FHWA 

regional directors, administrators, and engineers. 

“The focus must be to keep good pavements in good 

condition, preserving the pavement asset while 

maximizing the economic efficiency. Our experience with preservation programs is showing that 

DOTs are gaining flexibility for funding capital 

needs while providing the traveling public higher 

level of service. Pavement preservation provides 

greater value to the highway system, improves safety, enhances mobility, and provides a higher level of 

satisfaction of highway users.” 

To execute the outreach this year, the FHWA has 

turned to the National Center for Pavement Preservation. NCPP has been fighting for change in the 

conventional wisdom, and observes that the majority of the United States population travels through a 

work zone at least once per day, and that 80% of 

federal-aid funds go into products the public sees in 

work zones. NCPP wants to redirect the conventional thinking that new construction is most desirable, and that worst pavements should be fixed first. 

Instead, it wants to promote efficient road preservation programs for highway agencies. 

For this 2005 project, NCPP is charged with 

working within the goals of each state, and is visiting as a facilitator and advisor. For each visit, the 

NCPP will visit with agency personnel involved in 

the development, implementation, and management of the state’s preservation program. 

"We have been contracted by the FHWA to conduct the state appraisals," NCPP's O'Doherty told 

Better Roads. "We have 20 states this first year with 

many more signing up for the second year. We will 

go into each state, spending a week visiting people at 

headquarters, districts, division and regional offices, 

and will be looking at some roads. We will make an 

appraisal that when completed can be used as a plan 

by the agency.” 

“This would include, but is not limited to, the 

departments of maintenance, planning, construction, research, and other areas as necessary to 

include all necessary organization elements,” the 

FHWA said. “The review should be tailored to the 

SHA’s existing programs, policies, guidance, specifications, and organizational structure. Information 

such as treatments used, the SHA’s mix of fixes, 

experience of performance to date, etc. will be necessary for the review.” Each review was anticipated 

to be 10 to 15 days over the duration of a twomonth period. 

Through the review of documentation, practices, procedures, economic evaluation and historical performance information, PMS information, 

and other sources, NCPP will assess the effectiveness of those agencies’ pavement preservation programs in terms of pavement performance, life, costeffectiveness, and other measures, and evaluate 

what aspects of the program or related areas of 

departmental operations could be refined or 

improved to provide a more effective pavement 

preservation program. NCPP will work with states 

to develop a roadmap of activities that can influ20 

Archived
ence the success of their pavement preservation 

program, the FHWA said. 

Los Angeles’ only choice 

Sometimes cash-flow problems mean a road agency 

has no choice but to incorporate pavement preservation principles into its program. That’s what the 

City of Los Angeles found recently as it incorporated two strategies into its long-term pavement 

preservation program: Rubberized asphalt slurry 

seals to prolong the life of its good pavements, and 

foamed asphalt and asphalt emulsion base recycling 

for failed pavements. 

It’s all being driven by the need to make limited 

funds go farther as the city grapples with maintaining and preserving its 6,500 miles of dedicated public thoroughfares (28,000 lane miles) and 800 miles 

of alleys in an area exceeding 466 square miles. 

L.A.’s renewed interest in pavement preservation 

is the result of California’s famous Prop 13, which 

dramatically cut taxes, including resources used for 

street repairs and paving, said William A. Robertson, 

director, Bureau of Street Services. 

“We quit doing maintenance,” Robertson said at 

a conference in January. “We quit doing slurry seal. 

The only thing we were doing was resurfacing, and 

calling it maintenance. So for a number of years— 

although we have the largest street system in the 

country—we were not doing any true maintenance, 

and we suffered greatly. We saw a drop in resurfaced 

streets from 275 miles a year to 118, because the 

money wasn’t there.” 

Over the last eight years the bureau has been able 

to convince elected officials that the city needed to 

take a hard look at preserving its transportation 

infrastructure. “We had to be innovative, and look at 

different ways to turn around our preservation program based on the little money that was available,” 

Robertson said. 

And that soul-searching has culminated in a new 

pavement preservation initiative that is based 

around rubberized slurry surfacings for pavements 

to prolong the life of pavements in better condition, 

and cold in-place recycling of failed pavements. 

“We now are using CIP recycling and an expanded slurry seal program simply to preserve the infrastructure we have in place,” Robertson said, adding 

the city had no choice if it was to have an adequate 

street system in the future. The city also continues to 

do asphalt overlays. 

Understanding that any program savings can 

vanish into municipal general fund, the base recycling machine—a 2200 CR from Wirtgen America Inc., the first in the United States—was purchased 

by the city council with a motion stating that any 

savings accruing from the use of the machine must 

stay in the BSS budget for pavement preservation. 

“The council put forward a motion instructing 

the CAO for the city, telling him he could not touch 

that money,” streets director Robertson said. “Any 

savings created by this machine would go right back 

into the preservation of our street system. That was 

a huge, huge step for which we had been fighting for 

years. We have been innovative and have thought 

outside of the box for years, but instead of being 

rewarded, they have taken those savings from us and 

told us to do more with even less money. But we 

now have the elected officials behind us, helping us 

preserve more miles of pavement each year.” 

PMS drives L.A. preservation 

Los Angeles uses a pavement management system to 

decide which streets will be reconstructed, which 

will be preserved with rubberized slurry seal, and 

which will be maintained in some other way, for 

example, crack-sealed, said assistant director of 

streets Nazario Sauceda. 

“A PMS is a scientific, systematic, consistent 

method for selecting maintenance and rehabilitation needs for determining the optimal time of 

repair, by predicting future condition,” Sauceda 

said. “In simpler words it’s a methodology that 

allows us to be cost-effective when we manage 

our pavements, and a tool that we use to support 

our decision-making.” L.A. uses the popular 

MicroPAVER from the U.S. Army Corps of Engineers, which uses the Pavement Condition Index 

method for rating pavements, complies with GASB 

34, and is used by more than 600 cities, counties, 

airports, and consulting firms. 

GASB 34 is short for Government Accounting 

Standards Board Statement 34, which requires that 

state and local governments include the value of 

long-lived assets, including roads and bridges, in 

their annual financial statements. 

Pavement management “in the good old days,” he 

told Better Roads, included routine maintenance 

cycles, priority on a worst-first basis, which would be 

driven by citizen complaints and political priorities, 

or recommendations by the old superintendent. 

21 

Archived
Modern PMS, though, are light years removed base recycling. And a pavement inspection and 

inventory is key. 

“Our goal is to inspect all 6,500 miles in three 

years, so each year we view 2,200 miles of streets,” 

Sauceda told Better Roads. L.A. uses two semi-automated survey vans which take digital pictures of 

pavements, which are analyzed for stresses. “Based 

on that information, we calculate the PCI of the 

street,” Sauceda said. “Our qualified staff also will 

conduct investigations by hand. Sometimes you 

may take a picture that will not be accurate, so our 

guys will confirm the condition in person.” 

The pavement condition is predicated on how 

different distresses will impact street performance 

from the old days, he said. They can be used to justify different funding level requests, provide information to make efficient use of limited resources, 

produce quantified and accurate data, track pavement performance, identify current and future 

maintenance and rehab needs, select cost-effective 

repair strategies, and predict future pavement conditions based on different budget scenarios. 

This PMS enables L.A. to determine which 

streets are deserving of preservation with rubberized slurry surfacings, and which are so far gone 

that preservation funds would be wasted. Those 

become reconstruction candidates for full-depth 

Township Preserves Roads–and the Budget 

A rural township west of New York City is making its limited 

road budget go further by rigorously preserving pavements 

with polymer-modified fiber-membranes and paver-placed, 

ultra-thin surface treatments, prolonging pavement life and 

satisfying its new commuter residents who demand smooth 

pavements. 

The Town of Minisink, located just north of the New Jersey 

border in Orange County, about 55 miles from Manhattan as 

the crow flies, is a rural jurisdiction now being populated by 

commuters who can drive to nearby rail and bus stops for their 

daily journeys to New York City. As such, increased demands 

are being placed on the 102 lane miles of town roads which 

could lead to their destruction, if not for the pavement preservation practiced by the town. 

In July, Minisink was surfacing what it considered to be 

some of the worst roads in the town, but anywhere else they 

would not appear to be in such bad shape. That’s because the 

town has actively been preserving its pavements for years. 

“We don’t want the cracks to get any worse, and we don’t 

want the base to fail,” said Randy Filipowski, highway superintendent, Town of Minisink, New York. “We find that this surfacing process cuts reflective cracking at almost 90% over the 

last three years on roads where we’ve used it. It works out well 

and offers a good bang for your buck. We’re the smallest town 

in Orange County, with the smallest budget, and we have to 

make our money stretch.” 

The fiber-membrane 

In July, contractor Midland Asphalt Materials was placing 

FiberMat surfacing on a number of roads in Minisink. The 

fiber-membrane process suppresses reflective cracking, preserves the pavement, and provides a permanent riding surface 

that can stand on its own, or it can be surfaced later with 

NovaChip, or a hot-mix asphalt overlay. 

“The fibers form a mesh within a double seal, which bridges 

the cracks,” Filipowski said. “As everyone in the highway industry knows, the object is to keep water out of the base, and to keep 

the fines from moving around. Catching the cracks at an early 

stage like this, where they’re only 0.25- to 0.375-inch deep, stops 

the road from coming apart. We want to seal before chunks start 

coming out of the road, so we don’t have to patch.” 

The surfacing used there consists of 2.375-inch-long fibers 

that are individually cut and randomly dispersed into the first 

layer of a special CRS-1P type polymer-modified emulsion 

sprayed by the specialized trailer unit. That layer is immediately 

topped by another emulsion spray, which covers and encapsulates the fibers, sealing them in, all in one pass. The tanker and 

specialized trailer unit can move forward rather quickly, with 

typical speeds of 250 to 300 feet per minute. A standard chip 

spreader then applies the aggregate. 

The FiberMat surface being placed in Minisink will be used as 

the driving surface until the season of 2006, when it will be overlaid with NovaChip ultra-thin surface treatment from Sem Materials; thus it will serve through the winter as a driving course, 

then next year as a stress-absorbing membrane interlayer. 

The reason is that the town simply can’t afford to do both 

surfacings at the same time, so it works incrementally, confident 

that the fiber-membrane will serve all winter until overlaid in 

the spring. “Use of the FiberMat followed by NovaChip costs 

less money than asphalt overlays, and we get the SAMI function 

as well,” Filipowski said. “This process allows us to resurface up 

to 6 miles of roads a year in this fashion.” 

22 

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in L.A.’s mild climate, but with rigorous traffic loadings, Sauceda said. “A PCI of 70 to 100, the street 

will be very good to excellent,” he said. “40 to 70 is 

fairly good. But with a PCI of zero to 40, the pavement will not be in good shape.” 

Rubberized slurry seals 

For streets not requiring complete reconstruction, 

L.A. has adopted a rubberized slurry seal as a standard. This product, called FlexSeal—manufactured 

locally by Petrochem Marketing, Inc.—is an emulsion of oil, rubber, and fine sand. “It’s a preservative 

application or sealant that inhibits oxidation of oils 

from the pavement, deters asphalt cracking, and prevents water from seeping into the sub-base,” Sauceda 

told Better Roads. “It extends the street’s serviceable 

life, thereby reducing the need for repaving.” 

The use of rubberized slurry seals has enabled 

L.A. to expand its slurry program from 100 to 300 

miles per year, and hire an additional crew. The city 

also has fielded requests for information from counties and cities in California, and Caltrans, in addition to cities from Nevada to Texas to Wisconsin. 

Despite the low cost and serviceability of conventional slurry seals, L.A. chose to get out of that program due to logistical problems. They required a 

base camp to be set up in local neighborhoods, 

Enhanced aggregate retention 

The thickness provided by the fibers and twin emulsion layers 

also enhances chip retention. “The chip is imbedded in the 

emulsion, which has bonded to the fibers,” said Daniel J. 

Koeninger, P.E., Midland Asphalt Materials Inc. “When the 

aggregate chip is under stress due to traffic, the emulsion and 

fiber provide tensile strength to retain the chip.” 

The fibers make it unique, Koeninger said. “There is no 

other product that gives this kind of coverage. There is no comparison with non-woven/needle-punched overlay fabric, 

because it’s usually applied in a manner where it cannot fulfill 

its purpose. There will be bunching, tears, and wrinkles around 

curves, and they all reflect back to the surface. Also, this product can be installed directly on a milled surface.” 

In the Town of Minisink, the FiberMat SAMI was dosed at a 

rate of 0.16 pounds of glass fibers per square yard. The modified asphalt emulsion was applied in two simultaneous applications which total 0.4 to 0.5 gallons per square yard depending on surface and conditions. A quarter-inch top-sized stone 

was placed on the sprayed membrane to blind-in the surface 

before an overlay is placed at a later time. 

When the process is used as a wearing course seal, the glass 

fibers are applied at a lesser rate of at least 0.11 pounds per 

square yard, depending on the severity of the cracking. The 

membrane sandwich is followed by placement of 0.25-, 0.375-, 

or 0.5-inch top-sized aggregate, or a mix of those sizes as in a 

double dressing. 

For either formulation, the chips are seated into the surface 

by a pneumatic tired roller, and the pavement opened to traffic 

in a quarter-hour. “With this process we don’t keep anyone out 

of their homes or stop them from going anywhere,” Filipowski 

said. “Very seldom will we close a road.” 

The application unit is improved over the configuration 

available just a year ago. “The fiber capacity has been increased 

four-fold,” Koeninger said. “The fiber machine can go farther 

before having to reload fiber. The efficiency of the new cutting 

unit allows the material to be deposited more rapidly. As a result 

it can potentially do up to 70,000 square yards per day, depending on site conditions.” The machine is towed by a tanker or an 

ordinary distributor. “The new machine lays the fiber out very 

uniformly and even,” Filipowski said. “They’ve come a long 

way.” 

Voters demand a black finish 

While the township has the option of using the process as a permanent, stand-alone driving surface—instead of the other 

overlays—Filipowski won’t do it. “We’re only an hour out of 

Manhattan, and the people moving in are used to blacktop or 

concrete roads, and they’re really not enthusiastic about oil and 

chips,” Filipowski said. “The NovaChip is a very good intermediate process between HMA and oil and chip, so we do the fiber 

process first, and place NovaChip on top later.” 

And because the township road superintendent is an elected 

position, providing good roads, surfaced the way the voters like, 

is paramount for Filipowski, who faces election soon. “It’s our 

third year with the process, and we’re happy,” he said. “They 

haven’t hung me yet. Until something better comes along, we’re 

going to stick with it.” 

Information for this article contributed by Midland Asphalt Materials Inc. 

23 

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including as much as 50 to 100 tons of sand and 

aggregates, plus stationing of large pieces of equipment for the duration of the project, for as long as 

one month. There would also be environmental 

issues of dust and noise pollution, noxious odors 

during mixing, daily equipment maintenance, and 

its inability to consistently pass acceptable testing 

standards. 

“There would be a tremendous neighborhood 

impact with our equipment,” Sauceda said. “We 

would store materials on-site, and large pieces of 

equipment, and that causes a big problem in L.A., 

where people are picky about their streets, their 

trees, and quality of life.” 

Instead, the private-sector-produced slurry seal 

is a premixed, rubberized material that is plantmixed and delivered ready for distribution on a 

project site. The material is distributed through 

PMI applicator trucks under the direction of bureau 

forces. Furthermore, it’s continually tested by the 

city’s Department of General Services Materials 

Testing Laboratory, to ensure product compliance 

with spec. The testing is out of the hands of the 

Bureau of Street Services. 

Recycling failed roads 

Today, L.A.’s bureau has retrofitted its two municipal asphalt plants to increase their capacities to 

incorporate 20% of reclaimed asphalt pavement 

into the asphalt manufactured at these plants. The 

city also has a contract with a private sector supplier for a 50% RAP, 50% virgin plant mix, used in all 

phases of the city’s resurfacing program. 

Cost savings drive this effort. The city recognizes 

that RAP recycling results in a reduction in demand 

for virgin aggregates, reduced construction time, 

less truck traffic and its environmental impact, and 

overall reduced environmental impact. 

But base recycling offers even more savings over 

conventional reconstruction, said assistant director 

of streets Thomas W. Thomas. By contrast, he said, 

conventional reconstruction involves excavation 

and removal of existing material, transport of the 

material to city-owned or private asphalt plants, and 

then importation, placement, and compaction of 

new base materials and new asphalt concrete, with 

accompanying prolonged lane closures and excessive truck traffic. 

“We’re concentrating on our failed streets, with 

an ultimate goal this year of saving $2.4 million a 

year based on a resurfacing program of 150 miles, 

with an increase of 15 additional miles in FY 2005­

2006 paid for from that savings, with no increase in 

the budget.” 

L.A. is using the 2200 CR to do foamed asphalt 

recycling throughout the city, and will be using it for 

emulsion stabilization as well, Thomas said. Challenges in foamed base recycling include the need for 

a minimum of 48 hours of dry weather, and maintenance of liquid asphalt temperatures of 340 to 350 

degrees F. 

“The crew personnel assigned to the CIP program are committed to a successful program and 

adapted very quickly to the new technology, since 

they were experienced in cold milling and paving 

operations,” Thomas said. “The division management and superintendent staff are also committed 

to the CIP program and a team effort by everyone is 

required for a successful program, including the 

support of the Department of General Services, 

which develops the mix designs and provides testing 

services.” 

Foamed asphalt is created by carefully injecting a 

predetermined amount of cold water into hot penetration-grade asphalt in the mixing chamber of a 

pavement remixing unit, and offers a cost-effective 

alternate for road base stabilization. Precise addition 

of water allows control of the rate of asphalt expansion and the amount of expansion. 

The expanded asphalt has a resulting high surface area available for bonding with the aggregate, 

leading to a stable road base using the existing inplace materials. The benefit is substantial cost savings over use of asphalt emulsions for base stabilization, and complete elimination of the cure or break 

period. The foamed base then is graded and compacted, and can permit traffic—including heavy 

trucks—almost immediately. 

L.A. got a hands-on look at foamed asphalt stabilization in the reconstruction of Mt. Lee Drive 

above Hollywood in 2003. Not only did the process 

result in a successful reconstruction, but it eliminated an estimated 864 truck trips, greatly reducing 

construction traffic, noise, and pollution through a 

mountainside residential area with narrow, winding 

roads. The existing pavement was recycled to a 

depth of 6 inches, while applying 3% foamed 

asphalt (by mass). The new, completed base was 

covered by a light tack coat, followed by surface 

brooming and application of microsurfacing. 

“We got a really good base out of it,” Thomas said 

in January. “It’s been over a year and it’s held up 

through all the rains we had over the winter.” 

24 

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Thomas estimated, in retrospect, that a conventional rebuild would have taken 44 days and cost 

$400,000; but the foamed asphalt rebuild was completed in just seven days at a cost of $100,000. 

Nashville takes initiative 

The combined city-county of Metro Nashville has 

gone full-throttle in adopting and justifying to the 

public its pavement preservation program. On its 

Web site, Metro Nashville defines its PMS and then 

says how it will use it to husband its highways and 

make scarce dollars go farther. 

“A pavement management system is a computerassisted process that examines all public roads and 

determines the best means to preserve and repair 

each road individually and the road system as a 

For More Information 

A vast amount of information on pavement preservation is 

available to pavement professionals, and it’s growing faster 

and faster. Here are some places to start: 

•	 The Web site of the National Center for Pavement Preservation—www.pavementpreservation.org—has a growing 

library of technical and practical application papers. Visit 

the Library and also check out What’s New. 

•	 For a more in-depth look at asset management, download 

the Asset Management Primer (.pdf file) from the FHWA 

Office of Asset Management Web site, at www.fhwa.dot. 

gov/infrastructure/asstmgmt/amprimer.pdf/. There are 

many other documents on the Web site that will be of 

interest to readers of Pavement Preservation newsletter. 

Visit them at www.fhwa.dot.gov/infrastructure/asstmgmt/ 

index.htm/. 

•	 The International Slurry Surfacing Association has 

released its newest informational product, a DVD containing two videos: Preventive Maintenance—It’s a Decision, and Surfacing Systems: Pavement Performance Champions, packaged in a printed, four-fold brochure. The 

package explains the advantages, benefits, and economies 

of pavement preservation and slurry system preventive 

maintenance applications for existing asphalt roadways. 

The brochure and videos explain in lay terms and compelling graphs and graphics, the reasons for preventive 

maintenance and slurry systems (microsurfacing and slurry seal). The kits are available through ISSA member comwhole,” Metro Nashville informs its citizens in a 

pavement preservation plan. “Decisions are based 

on pavement condition, ride quality, costs of treatment, benefits to the road, and benefits to the road 

system. Because maintenance funds are always limited, the management system recommends the optimum sequence of repairs to make the best use of 

taxpayer dollars. The system provides a fair and 

equable way to compare repair needs in all the city’s 

neighborhoods to ensure the decisions are in the 

community’s overall best interests.” 

Like L.A., Metro Nashville public works uses specially-designed digital survey vehicles to photograph every public street in Davidson County. 

Trained technicians then view sections of a road to 

determine the amount of pavement damage, using a 

uniform scoring method. Measuring devices 

panies; locate them on the ISSA Web site, www.slurry.org. 

•	 The new National Cooperative Highway Research Program synthesis of best practice—NCHRP 35-02: Chip Seal 

Best Practices—is now available. Download it at 

http://trb.org/publications/nchrp/nchrp_syn_342.pdf. 

•	 NCHRP Report 523: TRB’s National Cooperative Highway 

Research Program (NCHRP) Report 523: Optimal Timing 

of Pavement Preventive Maintenance Treatment Applications describes a methodology for determining the optimal timing for the application of preventive maintenance 

treatments to flexible and rigid pavements. NCHRP 

Report 523 also presents the methodology in the form of 

a Microsoft Excel Visual Basic Application, called 

OPTime. It may be downloaded (at no charge) at 

http://trb.org/news/blurb_detail.asp?id=4306. 

•	 All six pocket-sized, spiral-bound editions of the Pavement Preservation Checklist Series—sponsored by FP2 

and the FHWA, are available from NCPP. They are No. 1, 

Crack Seal Application; No. 2, Chip Seal Application; No. 3, 

Thin Hot-Mix Asphalt Overlay; No. 4, Fog Seal Application; 

No. 5, Microsurfacing Application; and No. 6, Joint Sealing 

Portland Cement Concrete Pavements. Obtain them from 

www.pavementpreservation.org. 

•	 High-performance chip seals and other surface treatments 

were the subject of an article earlier this year; see Road Science: Making High-Volume Roads Last Longer, April 2005, 

pp 36–53. 

25 

Archived
mounted on the vehicle also 

record the amount of rutting in 

the pavement and evaluate the “Preservation involves
 

a paradigm shift from
 

worst-first to optimum
 

timing. Preservation 


programs must focus
 

on demonstrating 


benefit, securing 


commitment of top
 

agency management,
 

convincing the 


public, and selecting
 

the right treatment 


for the right 


pavement at 


the right time.”
 

ride quality. All this information 

is stored on a computer for processing using specialized pavement management software configured for Nashville’s needs. 

“MPW scores the streets in 

two categories—pavement stress 

and ride quality—to obtain an 

overall score for the street. Pavement distresses include cracks, 

potholes, and ruts,” Metro 

Nashville says. “Ride quality is the 

measure of how bumpy a road is. 

The scores help public works officials determine the best strategy 

for each street. One location may 

need a complete overlay while 

another street may only need 

some cracks repaired and potholes filled. By tailoring the repair 

decision to the needs for each street, based on the 

data collected, MPW can stretch tax dollars further 

while making the best repair decision for each 

street.” That’s the very definition of pavement 

preservation. 

Echoing classic pavement 

preservation philosophy, Metro 

Nashville says, “The secret to good 

pavement management is repairing roads that are still in fair condition but experiencing the early 

stages of pavement distress, 

reduced ride quality, and rutting,” 

MPW says. “By keeping those 

roads in good condition with 

lower cost repairs, MPW will still 

have money for reconstructing a 

few roads each year that are in the 

worst condition. A dollar in road 

repair spent early can give the 

same improvement as four dollars 

spent later in the road’s life when 

repairs are more expensive. If 

funds are spent only on the worst 

roads, our community will stay in 

a cycle where we can afford only 

to reconstruct a few roads in very 

poor condition each year while 

neglecting simple, lower cost repairs on other roads.
 

If we concentrate on the worst roads, we will never
 

catch up.”
 

ERES Division of Applied Research Associates,
 

Inc., is Metro Nashville’s pavement management
 

and preservation consultant. 

Reprinted from Better Roads, September 2005. Better Roads can 

be visited online at www.BetterRoads.com. 

26 

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Moving from Goal to Reality 

by Tom Deddens 

Make your pavement preservation goals a reality 

with help from new resources available from the 

Federal Highway Administration (FHWA), the 

National Center for Pavement Preservation 

(NCPP), and the Foundation for Pavement Preservation. 

Pavement preservation is a network-level, longterm strategy that enhances pavement performance 

by using a variety of cost-effective surface treatments that extend pavement life. These treatments 

must be carefully selected and must be applied 

before the pavement sustains structural damage. 

The benefits of a pavement-preservation program include improved pavement performance, 

increased roadway safety, higher customer satisfaction and reduced overall life-cycle costs. 

State and local highway agencies can gain a comprehensive understanding of pavement preservation 

through a new two-day course offered by NCPP, 

“Pavement Preservation: Applied Asset Management.” The course covers the components of preservation, benefits of undertaking a pavement preservation program and asset management principles 

and how they can be used to manage highway pavements. Also covered are data inventories, pavement 

distress identification and analysis, network and 

project level management and pavement preservation strategies. The course features hands-on group 

exercises as well, where participants can develop 

network-level preservation strategies and select 

treatments to complement the preferred overall 

strategy. 

A new course from FHWA’s National Highway 

Institute, meanwhile, offers strategies for incorporating a pavement preservation program into an 

overall pavement-management system so that work 

is coordinated and cost effective. The two-day 

course, “Pavement Preservation: Integrating Pavement Preservation Practices and Pavement Management” (Course No. 131104A), demonstrates how 

pavement-management tools can be used to support project-, network-, and strategic-level decision 

making and details the benefits of including pavement-preservation strategies in the pavement-management process. These benefits include being able 

to better assess the cost effectiveness of preventive 

maintenance activities and determine if pavement 

preservation goals can be met with existing funding 

levels. 

The course is designed for pavement and maintenance engineers who manage pavement preservation programs, as well as planning and programming personnel. 

Additional pavement-preservation courses available from NHI are: 

•	 The Preventive Maintenance Concept (No. 

131054A); 

•	 Selecting Pavements for Preventive Maintenance 

(No. 131058A); and 

•	 Design and Construction of Quality Preventive 

Maintenance Treatments (No. 131103A). 

For states who would like assistance in developing or expanding their pavement-preservation programs, FHWA’s Office of Asset Management has 

launched a Pavement Preservation Technical Assistance Program. The NCPP will work with the individual state department of transportation and the 

local FHWA division office to conduct interviews 

with key personnel and assess pavement-preservation procedures and policies. 

A closeout meeting will be held with the participants from each state to discuss the assessment and 

any recommendations or suggested improvements 

for the future. 

To learn more, visit www.fhwa.dot.gov/ 

infrastructure and click on “Pavement Preservation 

Technical Assistance Review and Evaluation.” 

Information gathered during the assessments 

will also be used to create a database that can track 

27 

Archived
Pavement preservation treatments must be carefully selected and must be applied before the pavement sustains structural damage. 

pavement preservation practices and trends across 

the country. 

Collecting this data nationally will provide information on the expected service life of various 

preservation treatments and on variables that can 

adversely affect treatments, such as application timing, environmental factors, and traffic loads. These 

state evaluations will establish a much needed baseline and will serve as a sound benchmark for states 

seeking improvement. 

Deddens is a system preservation engineer for FHWA’s 

Construction and System Preservation Team. 

Reprinted from Roads & Bridges, August 2005. 

*The FHWA contact for current information on this topic is 

Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

28 

Archived
Anticipation is Sweet 

Research Examines Results of Preventive Maintenance on 

Pavements After 14 Years in Service 

by Larry Galehouse, P.E., P.S., and John O’Doherty, P.E. 

When applied early, preventive maintenance treatments used as part of a sound pavement preservation strategy will cost less than the reconstruction 

and rehabilitation of highways that are allowed to 

deteriorate. Michigan, which has been active in 

implementing pavement preservation programs, 

has experienced as much as a 10:1 return on preventive maintenance investments. 

Network pavement quality improvements also 

have rewarded states with preservation programs. 

Since instituting a pavement preservation program 

in the early 1980s, the Kansas Department of Transportation has seen its good pavements increase 

from less than 50% in 1983 to approximately 95% 

in 2003. Yet, despite advances in materials and clear 

benefits gained over the past 14 years, we still need 

to gain a better understanding of the optimal timings for the application of the various preventive 

maintenance treatments. 

While we all want highways to improve using 

available funding, it takes time for a preservation 

strategy to produce readily observable results. 

Despite the plethora of professional courses, training workshops, seminars, CDs and video programs 

promoting pavement preservation for agencies and 

industry, a lack of good, real-world data tends to 

inhibit the understanding and general acceptance of 

the concept. Here, we want to further document the 

effectiveness of pavement preventive maintenance 

treatments, some of which have far exceeded their 

expected service lives. 

Sections to the test 

The Specific Pavement Study-3 (SPS-3) project 

titled, “Preventive Maintenance Effectiveness of 

Flexible Pavements,” part of the Strategic Highway 

Research Program’s (SHRP) Long Term Pavement 

Performance (LTPP), compared the effectiveness 

and mechanisms for selecting maintenance treatments to preserve and extend flexible pavement 

service life, safety and ride quality. The overall goal 

was to assess the benefits of treating test sections 

rather than scoring the relative performances of 

various treatments. Study factors included climatic 

zone, subgrade type, traffic, initial condition and 

structural adequacy. Treatments tested were slurry 

seal, chip seal, crack seal and thin hot-mix asphalt 

(HMA) overlay. 

SHRP administered the LTPP project for its first 

five years, after which it was managed by the Federal Highway Administration (FHWA). The FHWA’s 

DataPave Internet site contains performance data 

collected on individual projects. The FHWA’s Pavement Division formed Regional Expert Task Groups 

to conduct periodic field performance reviews of 

the treatments. 

Although some of the SPS-3 projects were later 

overlaid, 48% were still operating in 2004 when the 

seven projects had been visited, photographed and 

analyzed for performance after 13 or 14 years of 

service—long past their expected design lives. DataPave data also were analyzed. 

The SPS-3 research sought to define the most 

effective treatment application timings, evaluate 

treatment effectiveness for prolonging pavement 

lives and share information and experience among 

highway agencies and industry. SPS-3 projects comprised five test sections: an untreated control, a thin 

HMA overlay, an emulsion slurry seal, a crack-seal 

section and an emulsion chip seal. Some states also 

tested other sections. Eighty-one SPS-3 sites with 

486 test sections were placed in the U.S. and Canada in 1990 and 1991. All sections were monitored 

for performance by LTPP. 

The Expert Task Groups developed site-specific 

construction specifications and coordinated construction. To reduce variability, the same placement 

crews and supervision were used throughout each of 

29 

Archived
the four LTPP regions for slurry and chip seals. The 

same slurry seal emulsion was used for all projects, as 

was a single chip seal emulsion. Aggregates varied by 

state. The crack sealing materials and crews were the 

same in each region. Thin HMA overlays were provided by local agencies, with a different HMA and 

placement crew at each site. For the seven projects 

described here, the HMA overlay lift thickness varied 

from 0.7 in. in Texas to 1.8 in. in Missouri. 

Under scrutiny 

LTPP and the regional Expert Task Groups evaluated section performances through the first five years. 

Some deteriorated sections were overlaid and abandoned. State monitoring continued on several of the 

remaining sections. Evaluation tools included the 

following: 

•	 Distress surveys using the SHRP P-338 Identification Manual; 

•	 Deflection using a falling-weight deflectometer; 

•	 Ride quality, or longitudinal profile, using the 

K.J. Law-type profilometer; and 

•	 Rut depth using PASCO data and Dipstick. 

After the planned five-year evaluation period, several reports were written, and the Expert Task Groups 

formed the following general conclusions: 

•	 Preventive maintenance treatments generally 

outperformed control sections; 

•	 Treatments applied to good pavements gave 

good performance; 

•	 Traffic and structural adequacy did not appear to 

affect performance; 

•	 Crack seals performed best when cracks were 

pre-routed and provided the most benefit when 

applied to good pavements; 

•	 Slurry seals were best in no-freeze climates, outperformed controls and were most effective on 

good pavements; 

•	 Chip seals performed well except when placed 

over pavements in poor condition in wet-freeze 

zones; 

•	 Thin overlays consistently outperformed 

untreated controls; and 

•	 Generally, preventive maintenance treatments 

exceeded expectations. 

resenting a broad cross section of environmental zones, were constructed in 1990 and evaluated in 

2003 and 2004. The selected projects represent wet, 

no-freeze and wet, freeze zones; southern, northcentral and western regions; and 1990 annual equivalent single-axle loads between 11,000 and 307,000. 

The LTPP DataPave analysis for the seven projects revealed: 

•	 The International Roughness Index showed no 

observable trend; 

•	 Thin HMA overlay sections had slightly better 

overall rut performance than other treatments. 

(This may have been affected by pre-existing rutting in the wheel paths.); 

•	 Chip seals provided the best overall cracking performance. This observation is consistent with a 

Texas DOT report of a study of 14 SPS-3 Texas 

projects; 

•	 Initial cracking tended to be reflective, caused by 

underlying cracks or by thermal forces or both, 

and later by fatigue; 

•	 Initially, cracking in the slurry and chip seals 

diminished, only to resume when the slurry seals 

began to wear off; 

•	 Except for thin overlays, the treatments increased 

initial roughness; and 

•	 Thin overlays produced the smallest changes in 

roughness, while the control and crack seal sections produced the largest increase in roughness. 

Pay more later 

Pavement preservation is a long-term strategy 

enhancing functional pavement performance using 

integrated, cost-effective practices that extend pavement life, improve safety and motorist satisfaction 

while achieving sustainable, manageable condition 

levels for pavement networks. Pavement preservation includes routine and preventive maintenance 

and minor rehabilitation. 

Reconstruction replaces an existing pavement 

structure with an equivalent new pavement structure. Rehabilitation, including restoration treatments and structural overlays, enhances an existing 

pavement’s structure to restore its load capacity. 

Resurfacing applies additional pavement material 

(typically more than 1.5 in.) to provide more structural integrity or improved rideability. The reconstruction, rehabilitation and resurfacing costs in Figure 1 are from FHWA’s “Highway Statistics 2001” 

(the most recent available) publication and do not 

Although the North Atlantic region sections were 

abandoned by the end of the five-year experiment, 

after 14 years, 39 of the original 81 SPS-3 test sections were still operational. The seven projects, rep30 

Archived
Figure 1 

Annualized Cost per Lane Mile 

(Dollars) 

$20,000 

$18,537 Rural 

$18,000 Urban 

Preventive Maintenance Treatments (Rural & Urban) 

$16,000 

$14,626 

$14,000 $13,198 $12,285 

$12,000 

$10,000 $9,962 $9,654 

$8,000 

$6,000 $5,441
 

$4,000
 $3,387 $2,796 $2,581
 

$2,000
 

$0 

Reconstruction Rehabilitation Resurfacing

Average Design Service Life 

25 Yrs 15 Yrs 12.5 Yrs

Thin Overlay 

7.5 Yrs 

Slurry Seal Chip Seal

Average Life Extension

5 Yrs 4.5 Yrs

Crack Seal 

2 Yrs 

Note: 

Reconstruction, Rehabilitation and Resurfacing costs from Highway Statistics - 2001, FHWA 

Preventive Maintenance treatment costs from 2001 data, Michigan DOT 

include adding lanes to increase capacity. The annualized numbers assume a 20- to 30-year (average 25­

year) life for reconstruction, 10- to 20-year (average 

15-year) life for rehabilitation and 10- to 15-year 

(average 12.5-year) life for resurfacing. Costs vary 

regionally. 

SPS-3 project construction costs were atypical. 

Figure 1 exhibits typical preventive maintenance 

costs averaged from 66 projects of the same type 

placed in Michigan in 2001. They include mobilization, traffic control and required warranty bonds. 

They have been annualized for the average life 

extension to the underlying pavement, not the treatment life. Michigan assumed an average 7.5-year life 

extension from thin HMA overlays, 5 years from 

slurry seals, 2 years from crack seals and 4.5 years 

from chip seals. 

Agencies should determine treatment performances for their specific conditions. Figure 1 shows 

potential savings in a program emphasizing preventive maintenance. The annualized cost could be 

$2,600 for a crack seal or $2,800 for a chip seal to 

keep a good road in good condition (distinct from 

extending its useful life) at a mere fraction of the 

reconstruction cost. In fact, a simplified analysis 

shows that lane-mile costs for four slurry seal treatments applied over a 25-year period would be 

approximately $68,000, while without maintenance, 

the reconstruction cost would be $330,000. With 

performance similar to that of the projects examined here, even greater savings could be expected. 

LTPP DataPave website data were used to evaluate the seven SPS-3 projects after 13 or 14 years of 

service. These conclusions are only for the seven 

projects and may not apply to the 52% of SPS-3 

projects no longer in service. 

Significantly, after 14 years, chip seal sections are 

generally performing longer than expected, reducing longitudinal, transverse and fatigue cracking, 

and have been especially effective in sealing and 

protecting center-line joints. DataPave cracking 

results generally mirror the visual surveys. Slurry 

seals are showing signs of wear, but did provide sealing protection for most of their service lives, and 

their underlying pavements were generally in better 

condition than the crack sealed and control sections. Crack sealing results were mixed, confirming 

earlier conclusions by Expert Task Group observers 

31 

Archived
that routed seals perform better, and performance 

also may depend on pretreatment conditions. Conventional thin HMA overlays, ranging in thickness 

from 0.7 to 1.8 in., had the lowest International 

Roughness Indexes and rutting, but were then 

exhibiting fatigue (and other) cracking and some 

potholes. Some state-specific special sections did 

well (most notably the Bonifiber overlay in California), while others did not. 

Despite being in the most severe climate, Michigan’s SPS-3 project performed well, although it was 

in good condition before treatment. The Illinois, 

Michigan and Missouri original pavements were in 

the best condition of the studied sections, and 

inspections confirmed the efficacy of preventive 

treatments. The excellent conditions of the Michigan and other test sections clearly illustrate that preventive maintenance treatments in all climates provide protection and extend service lives when 

appropriately applied. Selection of the best treatment depends upon many factors including initial 

pavement condition, local availability of quality 

materials and construction, local user-delay costs, 

climate and traffic. 

Annualized costs show preventive maintenance 

treatments applied early in a pavement’s life are 

more cost-effective than allowing the pavement to 

deteriorate until it needs resurfacing, rehabilitation 

or reconstruction. A preventive maintenance strategy costs less and raises the overall quality of the road 

network, keeping good roads good. Preventive 

maintenance treatments reviewed here have performed well beyond their design lives, indicating 

even lower possible annualized costs and higher 

pavement quality. Since 1990, when these projects 

were initiated, we have seen many improvements in 

materials, construction techniques, equipment and 

performance-related specifications, and these 

improvements should extend pavement life and 

lower costs even more. 

Galehouse is director of the National Center for Pavement Preservation (NCPP), Okemos, Mich. O’Doherty is in charge of education 

and training at the NCPP. 

Reprinted from Roads & Bridges, June 2005. 

32 

Archived
A Helping Hand in Preserving 

Our Pavement Investment 

State highway agencies seeking to develop, expand, 

or improve their pavement preservation programs 

now have a valuable new resource available to them. 

The Federal Highway Administration’s (FHWA) 

Office of Asset Management has launched a Pavement Preservation Technical Assistance Program to 

work with highway agencies to evaluate their pavement preservation programs. The National Center 

for Pavement Preservation (NCPP) at Michigan 

State University in East Lansing, Michigan, will 

coordinate with the individual State and the local 

FHWA division office to conduct interviews to 

assess procedures, policies, and programs associated 

with pavement preservation. “The goal is to help 

States assess where they are and provide comments 

and recommendations on what they can do to further develop and enhance their pavement preservation programs,” says Tom Deddens of FHWA’s Construction and System Preservation Team. 

Pavement preservation is a network level, longterm strategy that enhances pavement performance 

by using a variety of cost-effective surface treatments that extend pavement life. These treatments 

must be carefully selected and must be applied 

before the pavement sustains structural damage. As 

implementation of pavement preservation programs increases nationwide, however, each highway 

agency faces different challenges in applying pavement preservation treatments and establishing an 

effective preservation program in its State. FHWA’s 

technical assistance program will help agencies 

assess their particular circumstances and address 

challenges that may exist. FHWA and NCPP will 

also benefit by obtaining data to establish a national baseline for pavement preservation practices. 

Each review will include approximately 80 hours 

of program assessment and interviews with key 

highway personnel involved in the development, 

implementation, and management of the State’s 

pavement maintenance, evaluation, and preservation programs. “The intent of the technical assistance will be to assess these components to identify 

both sound engineering practices and those practices that could be refined or improved to provide a 

more effective pavement preservation program,” 

says Deddens. A closeout meeting will be held with 

the participants from each State to discuss observations, make recommendations, and suggest 

enhancements and/or improvements. 

Information gathered during the assessments 

will be used to create a database so that pavement 

preservation practices and trends can be tracked 

nationally. “The database will provide a long-term 

tool for sharing best practices and assessing the success of the preservation program nationwide,” says 

Deddens. “It will also help us examine variables that 

can adversely affect pavement preservation treatments, such as application timing, environmental 

factors, and traffic loads. These results may also 

answer questions regarding the expected service life 

of various treatments.” 

For more information or to schedule a review, 

contact Tom Deddens at FHWA, 202-366-1557 

(email: tom.deddens@fhwa.dot.gov).* 

Reprinted from Focus, June 2005. 


*The FHWA contact for current information on this topic is 


Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

33 

Archived
New Course Offers “How to” for Integrating 

Pavement Preservation and Pavement 

Management 

Are you missing the data needed to determine 

whether your agency’s preventive maintenance 

activities are cost effective? Have you spent maintenance funds on a road scheduled for construction 

work, resulting in wasted money and effort? Or have 

you begun a pavement preservation program without knowing if you can achieve your goals with 

existing funding levels? Find out how to get the data 

you need, incorporate your preventive maintenance 

strategies into your pavement management system 

(PMS) so that work is coordinated and cost effective, and achieve your pavement preservation goals 

by attending the new National Highway Institute 

(NHI) course, “Pavement Preservation: Integrating 

Pavement Preservation Practices and Pavement 

Management” (Course No. 131104A). 

A pavement preservation program uses an integrated, cost-effective set of practices to extend pavement life, improve safety, and meet the expectations 

of motorists. Pavement management systems, meanwhile, aid in 

collecting and analyzing pave­ “Times have changed. 

It is no longer 

about identifying 

roads in need of 

rehabilitation, repair, 

or reconstruction. 

Today we must 

extend our highway 

investments by 

addressing surface 

deterioration and 

functional needs 

to get the most life 

out of our roads.” 

ment data and making planning 

and budgeting decisions. Bringing 

the two together is the focus of 

NHI’s new course. The course 

details how to integrate pavement 

preservation programs into an 

overall pavement management 

process. “Pavement preservation 

programs provide significant benefits to highway agencies, while 

pavement management systems 

provide the data that agencies 

need to measure the benefits. This 

course provides the essential tools 

and techniques to integrate the two,” says Jim Sorenson, Construction and System Preservation Team 

Leader in FHWA’s Office of Asset Management. 

Among the topics covered are the types of management decisions that are made by transportation 

agencies and the data that is needed to support these 

decisions. The course then demonstrates how pavement management tools can be used to support 

project, network, and strategic level decisionmaking, and outlines the benefits of including pavement 

preservation strategies in the pavement management process. 

“Integrating a pavement preservation program 

into an overall pavement management plan can help 

highway agencies develop a more comprehensive 

and coordinated road improvement plan, which 

includes maintenance needs as well as capital 

improvements,” says Katie Zimmerman, President of 

Applied Pavement Technology, Inc., which developed the course and will be teaching it for NHI. “Times have 

changed,” notes Tom Deddens, 

Preservation Engineer in FHWA’s 

Office of Asset Management. “It is 

no longer about identifying roads 

in need of rehabilitation, repair, or 

reconstruction. Today we must 

extend our highway investments 

by addressing surface deterioration and functional needs to get 

the most life out of our roads. This 

is preservation: selecting the right 

road for the right treatment at the 

right time. We need a PMS that 

includes preservation-related distress and maintenance strategies.” 

34 

Archived
The 2-day course is designed for pavement and techniques to consider in order to prolong our system’s pavement life.” 

The new course is the fourth in a series of pavement preservation classes. Other courses in the 

series available from NHI are: 

maintenance engineers who manage pavement 

preservation programs, as well as planning and programming personnel. The course development was 

supported by an expert technical panel that included representatives from Federal, State, and local 

transportation agencies. Industry representatives 

also provided support through the Foundation for 

Pavement Preservation. 

A pilot course was held in Raleigh, North Carolina, in August 2003. Since then, the course has been 

presented in Bal Harbour, Florida, for local and 

State highway agency personnel, and Lincoln, 

Nebraska, for staff of the Nebraska Department of 

Roads. 

“It was a helpful course,” says Gary Brhel of the 

Nebraska Department of Roads. “It gave us some 

tools and processes to use to help us integrate pavement preservation into our pavement management 

system.” Jerry Sudimick of the Florida Turnpike 

Enterprise attended the course held in Florida. “The 

class was very informative,” says Sudimick. “We have 

not implemented a pavement preservation program. However, I will be going back to the Turnpike 

Enterprise with considerably more information and 

•	 The Preventive Maintenance Concept (No. 

131054A) 

•	 Selecting Pavements for Preventive Maintenance 

(No. 131058A) 

•	 Design and Construction of Quality Preventive 

Maintenance Treatments (No. 131103A). 

For more information about the course content, 

contact John Taylor at NHI, 703-235-0524 (email: 

john.taylor@fhwa.dot.gov), or Tom Deddens at 

FHWA, 202-366-1557 (email: tom.deddens@fhwa. 

dot.gov).* Information is also available on the NHI 

Web site at www.nhi.fhwa.dot.gov. To schedule the 

course, contact Danielle Mathis-Lee at NHI, 703­

235-0528 (email: danielle.mathis-lee@fhwa.dot.gov). 

Reprinted from Focus, May 2005. 

*The FHWA contact for current information on this topic is 

Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

35 

Archived
Making High-Volume Roads Last Longer 

by Tom Kuennen 

Preservation techniques for local roads work for high-volume pavements, too— 

but top-flight discipline, designs, and materials are required. 

Crack sealing, chip seals, slurry surfacings, and thin 

overlays are part of a standard pavement preservation “tool box” for low-volume, secondary roads. 

Now, a growing accumulation of research indicates 

these same techniques also work on high-volume 

roads, but with a catch: success demands a disciplined approach to these techniques rather than the 

seat-of-the-pants, intuitive procedures that often 

mark work done on low-volume pavements. 

Where chip seals might have been done by 

agency forces using tried-and-true, “hand-medown” procedures with off-the-shelf binder and 

chips, today’s successful chip seal for high-volume 

roads likely will be designed in a lab based on existing conditions, climate, and traffic loads, with a 

binder that is polymer-modified, and chip attributes that specify shape size, moisture content, and 

placement. 

And, rather than being installed by an agency’s 

general maintenance crew, it may be placed by a 

contractor—or a highly trained agency crew—with 

the quality controls and material suppliers that can 

assure the quality materials demanded for longterm performance. Its performance may be warranted. And in some instances, the preservation 

treatment may be a proprietary product that is 

available only through a dedicated contractor, such 

as an ultra-thin bonded wearing course like Koch’s 

NovaChip. 

As agencies invest more in preservation for highvolume pavements, competition for that market is 

growing. A case in point: Rather than conceding the 

prevention market to chip seal interests, the hot-mix 

asphalt industry has been supporting research into 

thin asphalt overlays and how they fit into a pavement preservation program. 

And, all treatments are benefiting from new 

research that identifies best practices for pavement 

preservation for high-volume roads, and establishes 

valid lifecycle cost-analysis that makes the argument 

for increased budget emphasis on prevention more 

effective. 

New choices 

Conventionally, chip seals and other surface treatments have not been associated with high-volume 

arterial, collector, or interstate-type pavements. 

Instead, with regional exceptions, the preferred 

application is an asphalt overlay, following years of 

minimal care—typically, pothole patching and 

occasional crack sealing. But a variety of surface 

treatments for high-volume roads exists, and 

experts say they have the potential to prolong pavement serviceability at minimal cost. 

“Historically, the agency managers felt that the 

high-type asphalt and concrete pavements always 

needed an additional section of asphalt placed on 

them, and that chip seals, slurry seals, and other 

preservation treatments would not stand up to the 

traffic and loadings of those high-level pavements,” 

said Jim Sorenson, senior construction and maintenance engineer, Federal Highway Administration 

Office of Asset Management. 

“But with the advent of SHRP [Strategic Highway Research Program], 1988-1993, it was clearly 

demonstrated that preservation treatments were 

fully viable for any volume of road,” Sorenson told 

Better Roads. 

“There are the right techniques to use; for example, the chip seal must be properly designed, with 

good embedment and traffic speed held down. But 

on the Tacoma Narrows Bridge, with about 178,000 

ADT [average daily traffic], Washington State DOT 

has been putting chip seals on the deck for years” 

noted Sorenson. “They don’t want to add a lot of 

extra weight but need to keep friction up. Caltrans 

has main-line pavements on I-5 and I-80 where they 

did not think surface treatments would work, but 

the treatment has held up to the traffic.” 

36 

Archived
Such surface treatments can afford to have a 

higher quality aggregate in them, because other 

costs are lower. “As a result, their durability is much 

better,” Sorenson said. “The surfacings are not 

expected to carry the load or provide structural 

value, but to ward off the effects of aging and oxidation that Mother Nature sends. It’s a matter of putting them down right, and they will serve the pavement and traveling community in a very positive 

fashion.” 

Some preservation practitioners think that multiple treatments can preserve the structural soundness, drainage, and overall condition of roads for 

long periods of time. “Don’t think you can only mill 

out and replace,” Sorenson told Better Roads. “You 

may be able to use fog seals, slurry seals or microsurfacing, or chip seals, bettering the pavement performance cost-effectively, because these treatments 

clearly are showing a return on investment.” 

“A lot of people use a one-size-fits-all approach,” 

said Larry Galehouse, P.E., director, National Center 

for Pavement Preservation at Michigan State University. “It’s not cost-effective to do business that 

way. We have to look at what treatment will correct 

the deficiency, for the least cost, for the best performance. Pavement managers have to jump in with 

both feet, and gain this experience. Right now, a lot 

of agencies don’t have the institutional knowledge 

to take on preservation without some intense training. They have to cultivate the knowledge base within the agency, because there is a lot of poor practice 

out there.” 

One of the worst practices is waiting too long— 

that is, waiting for damage to develop—before preventive measures are applied, he said. “You’ve got to 

have a good pavement structure. If the pavement 

structure is sufficient to carry the load, we must 

keep the water out, maintain good skid resistance, 

and provide a smooth ride for the motorist. With 

pavement preservation techniques we will improve 

pavement performance and extend its life.” 

Most preservation actions used on asphalt or 

concrete low-volume roads are also suitable for 

higher-volume roads, Galehouse said.“For example, 

on good PCC pavements we can reseal joints, and 

on HMA, we seal the cracks,” Galehouse told Better 

Roads. “We can seal edges to avoid edge drops 

between the driving lane and shoulder, something 

that’s not done enough. We can microsurface and 

place thin bituminous lifts without concern for 

changing traffic volume.” 

Attention to preservation 

Years of research, publicity, and politicking on 

behalf of pavement preservation in the post-interstate era are beginning to bear fruit as closer attention is being paid to pavement preservation in 

national forums. 

Pavement preservation has been a strong topic of 

research at the annual Transportation Research 

Board meetings since 2000. The Federal Highway 

Administration and American Association of State 

Highway & Transportation Officials are putting 

resources into promoting pavement preservation in 

the context of transportation agency asset management. 

The Foundation for Pavement Preservation was 

founded in 1992 and now is administered out of 

Austin, Texas. And Galehouse’s NCPP, a strong 

resource for pavement managers, marked its first 

year of operation last fall. 

Also driving the interest in prevention practices 

for high-volume roads is a growing emphasis in 

government on asset management. 

The Midwestern Regional University Transportation Center in Madison, Wisconsin defines 

asset management as “a systematic process of operating, maintaining, and upgrading physical assets 

cost-effectively. It combines engineering and mathematical analyses with sound business practice and 

economic theory. Asset-management systems are 

goal-driven and, like the traditional planning 

process, include components for data collection, 

strategy evaluation, program selection, and feedback.” 

The asset management philosophy compels government agencies to borrow private-sector concepts 

of inventory, initial value, and net present value and 

apply them to their pavement system. That, in turn, 

helps them allocate their limited financial resources 

to optimize present and future road-system value. 

Asset management automatically puts the emphasis 

on life-cycle costing and how limited expenditures 

now can ensure optimal value later—and that is the 

very essence of pavement preservation practice. 

However, experts warn, high-level pavement 

preservation programming will only work if the 

bureaucracy of the highway agency supports it, and 

that can be tough in cultures that have traditionally 

focused on construction and renovation, and treated maintenance as an afterthought. 

37 

Archived
FHWA moves forward sion protection, spray-applied sealant for bridge 

parapets and piers, etc.” 

Low-volume roads 

Most pavements in North America and the rest of 

the world carry low traffic volumes, and there is a 

rich history of surface treatments being used in 

their management. 

In a 2005 TRB paper, Maintenance and Rehabilitation of Low-Volume Pavements in Washington 

State, Muench, White, Mahoney, Sivaneswaran, and 

Pierce confirm that “maintenance and rehabilitation 

practices on these roads are vital to their continued 

serviceability.” They also noted that such low-cost 

strategies are vital because “low-volume roads are 

typically managed by agencies with extremely limited resources.” 

The authors researched their state’s 30-year data 

base for low-volume pavement maintenance to 

reach their conclusion. “Records indicate that over 

two-thirds of WSDOT’s low-volume pavements are 

bituminous surface treatments, while almost onethird are hot-mix asphalt surfaced pavements,” they 

said. “These pavements, many of which have lasted 

in excess of 35 years, are in relatively good condition 

and are typically subject only to periodic rehabilitation treatments every 8 to 20 years and responsive 

pothole patching. This evidence suggests that the 

concept of a long-lasting low-volume pavement is 

viable and, in fact, already exists.” 

High-volume roads 

Many of those same practices can be used on highvolume roads as well. For example, chip seals can be 

used on interstate-type highways if done right, 

NCPP’s Galehouse said. 

“There are states that have successfully put chip 

seals on high-volume highways,” Galehouse told 

Better Roads. “They have developed an institutional 

knowledge that lets them be successful. Texas, California and Montana have done them. Trucks will 

take their toll on any treatment, and chip seals are 

no exception. But if a chip seal is done right it can 

stand up to trucks, provided there are no structural 

deficiencies.” 

“There is no magic ADT number or threshold 

for chip seal use,” said Steve Mueller, pavements and 

materials engineer, FHWA Resource Center, Denver. 

“Our new NCHRP Chip Seal Best Practice study 

shows that many countries are using chip seals on 

That pavement preservation deserves highest priority at the state DOTs was borne out last October, 

when the Federal Highway Administration strongly 

affirmed that pavement preservation expenditures 

are desirable and reimbursable under FHWA rules. 

In an October 8, 2004 memo obtained by Better 

Roads, FHWA Associate Administrator King W. Gee 

threw the weight of the FHWA behind pavement 

preservation. 

“Timely preventive maintenance and preservation activities are necessary to ensure proper performance of the transportation infrastructure,” Gee 

told division administrators and field services directors. “Experience has shown that when properly 

applied, preventive maintenance is a cost-effective 

way of extending the service life of highway facilities 

and, therefore, is eligible for Federal-aid funding.” 

And preservation gives states a path to optimizing their pavements for the long-term, he said. “By 

using lower-cost system preservation methods, 

states can improve system conditions, minimize 

road construction impacts on the traveling public, 

and better manage their resources needed for longterm improvements such as reconstruction or 

expansion. Preventive maintenance offers state 

DOTs a way of increasing the return on their infrastructure investment.” 

Eligibility of pavement preservation grew slowly 

during the 1990s, as Congress incrementally broadened the applicability of Federal-aid funding to preventive maintenance activities. “Congress’ acknowledgement of preventive maintenance activities as an 

eligible activity on Federal-aid highways is a logical 

step that reinforces the importance of implementing a continuing preventive maintenance program,” 

Gee said. 

Gee urged FHWA offices to work proactively 

with states to establish a preservation program, likely to include joint repair, seal coats, pavement patching, thin overlays, shoulder repair, restoration of 

drainage systems, and bridge activities such as crack 

sealing, joint repair, seismic retrofit, scour countermeasures, and painting. 

“Many other activities that heretofore have been 

considered routine maintenance may be considered 

Federal-aid eligible on an area-wide or system-wide 

basis as preventive maintenance (i.e., extending the 

service life),” Gee said. “This might include such 

work items as region-wide projects for periodic sign 

face cleaning, cleaning of drainage facilities, corro38 

Archived
high-volume roads, and that’s one of the report’s 

major findings. It’s an outstanding report which will 

advance the pavement preservation industry considerably.” 

Such seals tend to be polymer modified, Mueller 

told Better Roads at the 32nd annual Rocky Mountain Asphalt Conference and Equipment Show in 

February in Denver. “Polymer modification adds to 

the stickiness of the material, and holds the aggregates in on high-speed roadways. Public safety is a 

key issue here, and we certainly don’t want to damage vehicles from chip loss. The fact is that we can 

build chip seals with very low rates of loss, and 

properly designed and constructed chip seals can be 

used on high-volume roadways.” 

That properly designed surface treatments can 

hold up to traffic and weathering is borne out by 

research that now is coming to fruition. At January’s 

TRB meeting, proponents of pavement preservation 

gave an overview of just how well polymer-modified surface treatments can perform in different climates, based on 14 years of field experience. Visual 

surveys, photos, and data mining from the LongTerm Pavement Performance study’s DataPave Web 

site were used to evaluate the condition of seven 

research projects after 13 or 14 years in service. 

Preventive Maintenance Treatment Performance at 

14 Years was authored by NCPP’s Larry Galehouse, 

Helen King, and David R. Leach of Koch Pavement 

Solutions, Jim Moulthrop of Fugro Consultants, and 

Bill Ballou of the Foundation for Pavement Preservation. They concluded, “Perhaps the most compelling conclusion is that, after 14 years, the chip seal 

sections are generally giving longer than expected 

performance; reducing longitudinal, transverse, and 

fatigue cracking; and they are especially effective in 

sealing and protecting the centerline joints.” 

The slurry seals are showing signs of wear, but 

did provide sealing protection for most of their 

service life, and the pavements protected by the slurry seals are generally in better condition than the 

sections that were just crack sealed and the control 

sections, they said. “The results on the crack sealing 

sections are mixed, confirming earlier conclusions 

by ETG [expert task group] observers that the routed seals give better performance, and their performance may also depend upon the road condition 

before treatment,” they said. 

The contention that surface treatments will keep 

a top-flight road in top-flight condition also was 

borne out by the data. “The Michigan SPS-3 project, 

in the most severe climate, is among the best in 

overall condition,” they said. “It was also one of the 

projects in the best condition before treatment. The 

Illinois, Michigan, and Missouri original pavements 

were in the best condition of the sections studied for 

this report, and the photos and surveys show that 

the preventive treatments have kept them in the best 

condition. 

“The excellent condition of the Michigan SPS-3 

project and some of the other test sections clearly 

illustrates that preventive maintenance treatments 

in all climates do provide protection and extension 

of service lives when appropriately applied,” they 

said. 

Chip seal best practice 

That the best-designed chip seals can be used on 

high-volume pavements is illustrated in a new survey and practice presented in January at TRB. The 

paper, Chip Seal Program Excellence in the United 

States, by Dr. Doug Gransberg, P.E., University of 

Oklahoma-Norman, describes a survey of public 

highway and road agencies that use chip seals as part 

of their roadway maintenance program; the paper 

will become a part of the new NCHRP Synthesis 

Report 35-02 mentioned by the FHWA’s Mueller, 

Chip Seal Best Practices, (see For More Information 

sidebar). 

The survey was conducted to identify best practices in chip seal design and construction. “The 

study found that successful chip seal programs had 

much in common,” Gransberg said. “The major 

findings were that they used chip seals as a preventive maintenance tool applying it to roads before 

distress levels were classified as moderate. It also 

found that they require their contractors to use the 

latest technology and exploit advances in material 

science such as the use of modified binders. Additionally, most of these case study programs use chip 

seals on both high- and low-volume roads.” 

Chip seals date to the 1920s, Gransberg said. 

“These early uses were predominantly as wearing 

courses in the construction of low-volume gravel 

roads,” he said. “In the past 75 years, chip seals have 

evolved into maintenance treatments that can be 

successful on both low- and high-volume pavements. The popularity of chip seals is a direct result 

of their low initial costs in comparison with thin 

asphalt overlays, and other factors influencing treatment selection, where the structural capacity of the 

existing pavement is sufficient to sustain its existing 

loads.” 

39 

Archived
Among those agencies reporting excellent chip 

seal performance were Arkansas State Highway and 

Transportation Department; Colorado DOT; Idaho 

Transportation Department; Nevada, Oklahoma, 

Texas and Washington State DOTs; and the cities of 

Austin and Lubbock, Texas. 

“The most striking factor [is that] they use chip 

seals as a preventive maintenance tool by following 

a specific PM cycle,” Gransberg said. 

Research Gransberg uncovered in Texas shows 

that the design of a chip seal is paramount for performance. “One group followed formal design procedures...or local empirically developed procedures 

and utilized some form of input parameters, based 

on observed surface conditions, to calculate the rates 

of binder and aggregate application,” he wrote. “The 

other saw chip seal as a commodity and merely 

ordered an estimated amount of material and specified application rates based on past experience.” 

The carefully designed chip seals significantly 

outperformed their more casually placed counterparts. “Only one of the excellent case studies did not 

formally design its chip seals, and those that did utilized a procedure that has been in use for an average 

of 21 years,” said Gransberg. 

All use modified binders, with polymers and 

crumb rubber being the most common modifiers, he 

said. “They all select roads whose distress level is 

rated at moderate or less and whose structural crosssection is rated as fair or better, using some type of 

pavement condition rating as the trigger point to 

consider the selection of chip seal to extend the life of 

the pavement,” Gransberg said. “This further reinforces the use of this treatment as a PM technique 

rather than a repair method...these programs also 

follow-up to maintain their seals with routine crack 

sealing, and sometimes fog sealing, to maintain the 

integrity of the asphalt membrane for the life of the 

seal.” 

Gransberg found: 

•	 Chip seals should be viewed as a preventive 

maintenance tool to be applied on a regular 

cycle, and in doing so, reinforce the pavement 

preservation benefits of the technology. 

•	 Chip seals can be successfully used on high-volume roads if the agency’s policy is to install it on 

roads before pavement distress becomes severe 

or the structural integrity of the underlying 

pavement is breached. 

•	 Both hot asphalt cement and emulsified asphalt 

binders can be used successfully on high-volume 

roads; binders modified by polymers or crumb 

rubber seem to reinforce success. 

•	 In-house maintenance forces should be used to 

install chips seals in areas where the greatest care 

must be taken to achieve a successful product. 

•	 Requiring chip seal contractors to use state-ofthe-art equipment and to control the rolling 

operation enhances chip seal success. 

•	 Chip seal success requires an aggressive QC testing program combined with careful on-site 

inspections. 

Cracks come first 

In its Roadway Maintenance Surface Treatment 

Strategies (Recommended Guidelines), Caltrans 

says much the same thing for both contracted maintenance and that done by state forces. “Experience 

has shown when proper preparation has been done 

in areas scheduled for surface treatments (either by 

contract or by state forces), the life of the surface 

treatments can be greatly extended and helped in 

reducing lifecycle cost,” the California DOT said. “It 

is critical that all necessary preparation work such as 

crack filling, pothole repair, patching, leveling, 

digouts, etc., be done prior to surface treatments 

being placed.” 

Caltrans calls crack filling and sealing “our first 

line of defense in roadway maintenance.” The 

agency recommends cracks 0.25 inch or wider be 

filled or sealed before rainfall seasons or before the 

application of maintenance surface treatments such 

as fog seals, sand seals, slurry seals, chip seals, or 

maintenance overlays. 

“Cracks should be cleaned before filling or sealing,” the agency says. “When moisture is present or 

suspected, it is recommended that hot compressed 

air (hot lance) be used to prepare cracks immediately before filling or sealing materials are applied. 

All cracks should be squeegeed during filling and 

sealing (if product is left above the surface) to save 

materials, prevent road noise, improve ride quality, 

prevent bleeding or masking through future surface 

treatments, and prevent compaction problems on 

future overlays.” 

Caltrans also says crack fillers should be placed 

several months before future surface treatments, 

depending on local climatic conditions, to assure 

sufficient cure time for various crack-filling products. 

Premium crack-sealing products should be considered, Caltrans says. “Crack-sealing operations 

40 

Archived
can be very labor intensive,” the agency advises. “A 

value engineering study which involved seven states 

(including California) concluded that 66% of the 

total cost for these projects was for labor, 22% for 

equipment, and 12% for materials. Therefore, it 

may be more cost-effective to use a more expensive 

product that will last longer.” 

Polymer modifiers key 

Gransberg’s findings of the desirability of polymermodified binder in high-volume roadway chip seals 

was illustrated several years ago in South Dakota, 

which has had mixed success in surface sealing 

high-volume, high-speed roadways such as interstates. 

“Chip seals and sand seals have been the treatments of choice [in South Dakota] but they have 

been less successful on high-volume/high-speed 

roadways,” the FHWA said. “Chip retention is the 

major problem associated with these failures. The 

high number of broken windshields caused by loose 

chips has resulted in multiple claims on an individual project.” 

So a project was undertaken to investigate the 

use of chip seals for high-speed applications and to 

make recommendations to improve their performance. An extensive literature review was conducted 

to develop an understanding of the latest practices 

and experiences. Interviews were conducted within 

the South Dakota DOT to investigate chip seal practices and to determine areas for improvement. 

Finally, test sections were constructed to evaluate 

the performance of standard and modified chip seal 

designs. The test sections consisted of 12 chip seal 

designs and included two aggregate types (quartzite 

and natural aggregate) and alternate chip seal 

designs with new gradations and other modifications and enhancements. 

Recommendations were articulated in a January 

2002 Transportation Research Board presentation, 

Evaluation of Chip Seals on High-Speed Roadways. 

Authors Daris Ormesher, P.E., South Dakota DOT 

Office of Research; and Monty J. Wade, P.E., and 

David G. Peshkin, P.E., Applied Pavement Technology, Inc., said polymer-modified binders are the key 

to successful chip seals on South Dakota’s interstatetype, high-speed pavements. Performance can be 

enhanced through special considerations, such as 

the use of polymer-modified emulsions, precoated 

aggregates, or a fog seal cover. 

They recommended use of a polymer-modified 

emulsion to obtain better adhesion, especially on 

high-volume roadways, and the use of a fog seal 

over the chip seal to help with retention. 

Projects should be designed on a specific, individual project basis, and a higher emulsion application rate to achieve greater aggregate embedment 

should be considered, the authors said. 

They also concluded that a tighter and more gapgraded aggregate gradation should be developed to 

ensure uniformity and provide a single layer of 

chips, and that the amount of fines (material passing the 0.075-mm [No. 200] sieve) in the chips 

should be limited. Testing should limit the amount 

of flat and elongated particles in the aggregate, and 

also should determine adhesion between the aggregate chips and the emulsion. 

The authors said a surfaced pavement should be 

swept two hours after chip seal placement, and 

before opening to traffic; in the meantime, if used, 

the pilot vehicle should be run on the chip seal to 

assist chip embedment and orientation. An embedment check to ensure adequate embedment of the 

aggregate should be considered. And a choke stone 

layer of small chips over the chip seal to lock in the 

larger aggregate particles might be beneficial. 

Microsurfacing vs. slurry seals 

A major western contractor says high-performance 

microsurfacing is a superior choice for high-volume 

pavements. 

“On interstates we recommend microsurfacing, 

because you can get traffic back on it quickly,” said 

Brett Hone, project manager, Intermountain Slurry 

Seal, Salt Lake City, Utah. “Microsurfacing allows 

the contractor the capability to fill ruts by placing 

the aggregate more than one stone thick, then turn 

80,000-pound trucks back on to the filled ruts within one hour. The degree of heavy truck-caused rutting is the key factor over whether microsurfacing or 

chip seals would be used.” 

Hone said chip seals still have applications for 

interstates. “We’re still using chip seals on interstates 

and fog-sealing them after three days,” Hone told 

Better Roads. “With the proper application they’re a 

good solution; Utah DOT uses them every year. 

When you fog-seal the chip seal, it does a great job 

of holding the chip down, and gives the gray chips a 

black color for snow melt, and high contrast for 

striping.” 

For main arterial roads around town, Hone recommends slurry seals as a cost-effective maintenance product. “You would want to use a latex- or 

41 

Archived
polymer-modified Type III slurry seal,” he says, 

“because it has better bonding capabilities and the 

coarser Type III aggregate gives you a more aggressive surface for keeping skid numbers up high. And 

Type III slurry will cure out in less than four hours 

in the summer, which lets you get traffic back on it 

quickly. There is a little more downtime that way, 

but the cost savings compared to microsurfacing is 

half as much.” 

Intermountain has done fog-sealed chip seal 

projects with quarry-sourced 0.375-inch chips on I70 and I-15 in Utah, and reports that they last four 

to five years. “After three years, on some applications, they will apply a rejuvenator sealant, prior to 

placing another wear surface down three years after 

that,” Hone said. 

For either microsurfacing or chip seal, the highway has to be in good condition. “The highway will 

have to be structurally sound,” Hone told Better 

Roads. “Microsurfacing can fill in ruts, so long as 

you are confident the pavement has stabilized and is 

not subject to plastic deformation. My advice to 

states is to sit back and look at their wallet a little 

closer, and see where the money is going out the 

door. If they can maintain an asphalt surface by utilizing surface treatments in lieu of putting an overlay on top, they will be money ahead, because they 

can do twice as many lane miles with surface treatments. The key, though, is getting on them relatively quick, before they have oxidized and gotten brittle, and all the cracking has taken place.” 

Does joint sealing work? 

Pavement joint and crack sealants are designed to 

protect pavement by minimizing water infiltration 

and by preventing the accumulation of debris. 

“Crack sealing is an effective technique for maintaining flexible [hot-mix asphalt] pavements,” said 

the Transportation Research Board’s forward-looking state-of-the-industry forecast on the occasion of 

the Millennium. “Research has indicated that, in 

conjunction with maintenance techniques such as 

slurry seals and chip seals, crack sealing will extend 

the life of a flexible pavement.” 

The practice of sealing joints in rigid pavements 

has been subject to controversy. Research conducted 

by the Wisconsin DOT indicated sealing joints in 

concrete highway pavements was not cost effective. 

“Anecdotal information supports this finding,” the 

TRB panel found, adding “other information seems 

to show that joint sealant materials are vital to the 

protection of the pavement and that unsealed pavements deteriorate rapidly.” 

The challenge was thrown down at the 1996 

Spring Convention of the American Concrete Institute in Sacramento, and subsequently was articulated in The Effect of PCC Joint Sealing on Total Pavement Performance, a paper by Steve F. Shober and 

Terry S. Rutkowski of the Wisconsin DOT. 

Their research indicated that long-term pavement performance was not significantly affected by 

joint sealing, or its omission, and was not worth the 

expenditure of precious state maintenance funds. 

“WisDOT believes the burden of proof has shifted,” Shober and Rutkowski wrote. “No longer can 

anyone tout the merits of keeping water and incompressibles out of [pavement contraction] joints. 

Now, the burden is on researchers to prove through 

total pavement performance analysis that sealing 

PCC joints somehow enhances performance 

enough to be cost effective.” In a subsequent paper 

they found that asphaltic concrete (HMA) crack 

sealing was cost-effective in some cases, especially in 

improving winter ride. 

Realizing their findings constituted heresy to an 

establishment that maintained pavement joint sealing was intuitively valid, Shober and Rutkowski 

summoned up a scientific fallacy of the past. 

“Centuries ago, the concept of a spherical earth 

was viewed as preposterous,” they wrote. “Wisconsin’s research has posed a position that may be 

viewed similarly, that is: total highway pavement 

performance is not significantly affected by joint 

sealing or lack thereof. The challenge awaits others 

to provide compelling research on this issue.” 

Into the fray stepped New York State DOT’s outspoken innovative projects engineer John Bugler, 

and Burgess & Niple’s engineer Martin P. Burke, Jr. 

In their 2002 TRB paper, The Long-Term Performance of Unsealed Jointed Concrete Pavements, 

Bugler and Burke said Shober and Rutkowski had 

not used a long-enough time frame. 

“[I]t appears that WisDOT observations of test 

pavement performance were based on the mistaken 

assumption that the performance of pavements 

during their first 10 years of service was somehow 

indicative of their long-term performance,” Bugler 

and Burke said. “Such an assumption entirely neglects the characteristics of the pavement growth/ 

pressure phenomenon that typically becomes more 

destructive with pavement age. It also neglects the 

adverse long-term accumulative effects of surface 

and subsurface water movement on pavement 

42 

Archived
pumping and step-faulting, especially for pavements without dowels serving heavy truck traffic.” 

Unsealed pavement joints did not provide longterm cost-effective pavement performance, their 

research indicated. “As a result,” Bugler and Burke 

said, “the use of unsealed pavement joints has been 

discontinued by many major users familiar with the 

long-term performance of such applications.” 

But joint sealing had to be done right, they said. 

“Care must be taken in choosing high quality 

sealant material, the type and size of sealant for the 

chosen pavement joint and panel characteristics, as 

well as effective installation and inspection procedures, and periodic sealant repair and replacement 

practices.” 

New Pavement Preservation Boss at FHWA 

Tom Deddens, P.E., joined the FHWA’s Office of 

Asset Management as pavement preservation and 

construction engineer in February. He will manage 

the pavement preservation program, as well as the 

program manager moving the FHWA‘s interests in 

performance specifications. 

Deddens has 30 years’ experience in the industry. 

He worked more than 10 years in the U.S. Army 

Corps of Engineers, and has since worked in the private sector for several consultants, and in industry 

as a district engineer for the Asphalt Institute. With 

the Asphalt Institute, he provided technical assistance and training opportunities to the states of 

Arkansas, Illinois, Kansas, Missouri, and Nebraska, 

including maintenance of hot-mix asphalt pavements, rehabilitation of pavements using HMA, 

advanced Superpave mix design, and construction 

of asphalt pavements. 

Deddens is a qualified National Highway Institute instructor, having taught its course in Pavement 

Preservation: Selecting Pavements for Preventive 

Maintenance. He holds a bachelor of science degree 

(1975) from the University of Missouri-Rolla, and a 

master of science degree (1985) from the University 

of Kansas. He is a registered professional engineer in 

Kansas and Missouri, and has been professionally 

active in the Association of Asphalt Paving Technologists and American Public Works Association. 

FHWA’S List of Preservation Methods 

Asphalt pavements: 

•	 Crack sealing. 

•	 Patching. 

•	 Fog seals (a combination of mixing-type emulsion and approximately 50% water, used to seal 

shoulders and patches). 

•	 Rejuvenation (application of a rejuvenator agent 

in a procedure similar to fog sealing). 

•	 Sandwich seals (application of asphalt emulsion 

and a large aggregate, followed by a second application of asphalt emulsion that is in turn covered 

with smaller aggregate and compacted). 

•	 Sand seals (application of liquid asphalt or emulsions, covered with fine aggregate or sand, to 

improve skid resistance, prevent oxidation, and 

to seal against water infiltration). 

•	 Chip seals (surface treatment in which the pavement is sprayed with asphalt emulsion and then 

immediately covered with aggregate and rolled). 

•	 Slurry seals (an application of mixing-type 

asphaltic emulsion, sometimes with additives, 

mineral aggregate, and proportioned water, 

mixed and spread on clean pavement free of dirt 

and loose gravel). 

•	 Microsurfacing (polymer modified asphalt 

emulsion, mineral aggregate, mineral filler, 

water, and other additives, properly proportioned, mixed, and spread on a pavement). 

•	 Cape seals (application of slurry seal to a newly 

constructed surface treatment or chip seal). 

•	 Thin and ultrathin hot-mix asphalt overlays 

(single-lift surface course, generally with a thickness of 1.5 inch or less). 

Concrete pavements: 

•	 Patching. 

•	 Joint sealing. 

•	 Joint and spall repairs. 

•	 Load transfer retrofit. 

•	 White topping (similar to a thin HMA overlay, 

but using a fast-curing, high-durability concrete 

mix). 

For More Information 

More information about high-performance pavement preventive maintenance is available from a 

variety of sources. Begin with these: 

43 

Archived
Chip Seal Best Practices. The long-awaited National 

Cooperative Highway Research Program synthesis of best practice, NCHRP 35-02: Chip Seal Best 

Practices, should be available this spring. Visit 

this link to see if it has been announced: 

http://trb.org/news/blurb_browse.asp?id=5. 

Alternatively, locate it with a Google search by 

inputting: “NCHRP 35-02.” 

NCHRP Report 523. Optimal Timing of Pavement 

Preventive Maintenance Treatment Applications 

describes a methodology for determining the 

optimal timing for the application of preventive 

maintenance treatments to flexible and rigid 

pavements. NCHRP Report 523 also presents the 

methodology in the form of a Microsoft Excel 

Visual Basic Application, called OPTime. It may 

be downloaded (at no charge) at http://trb.org/ 

news/blurb_detail.asp?id=4306. 

A Pavement Preservation Strategy. Wisconsin’s carefully formulated philosophy on pavement preservation can be downloaded at www.dot. 

wisconsin.gov/library/research/docs/finalreports/ 

tau-finalreports/pavpreserv.pdf. 

Transportation Asset Management. Asset management is getting much play and new tools exist for 

pavement managers. Visit the Transportation 

Asset Management Web site of the Midwest 

Regional University Transportation Center of the 

University of Wisconsin-Madison, at www. 

mrutc.org/assetmgmt/index.htm. 

Capital Preventive Maintenance. The same center 

offers a strategy for getting support for preventive maintenance in your agency structure. Read 

Capital Preventive Maintenance, Project 03-01, 

February 2004 at www.mrutc.org/research/0301/ 

03-01final.pdf. 

Asset Management. There’s more on asset management at the American Association of State Highway & Transportation Officials Web site. Visit 

http://assetmanagement.transportation.org/tam 

/aashto.nsf/home. 

The Great Unsealing. Steve Shober’s controversial 

report on unsealed concrete pavement joints, 

The Great Unsealing, can be downloaded at 

www.dot.wisconsin.gov/library/research/docs/ 

finalreports/tau-finalreports/unsealing.pdf. Find 

many other useful WisDOT reports at www. 

dot.wisconsin.gov/library/research/reports/ 

pavements.htm. 

The Case for Joint Sealing. Burke and Bugler’s 

response to Steve Shober’s critique of PCC joint 

sealing, The Long-Term Performance of Unsealed 

Jointed Concrete Pavements, can be downloaded 

at http://irc.nrc-cnrc.gc.ca/fulltext/trb/02-2394. 

pdf. 

Hot or Cold. Read about Texas’ experience with hotpoured vs. cold-poured sealants in Field Performance of Hot Pour Sealants and Cold Pour 

Sealants, by Yetkin Yildirim, Ph.D., and Ahmed 

Qatan, BSc., University of Texas-Austin, at 

http://irc.nrc-cnrc.gc.ca/uir/ur/trb/docs/ColdpourVsHot-pourinTX_paper001215.pdf. 

Federal Highway Administration. The FHWA supports pavement preservation; visit its Web site at 

www.fhwa.dot.gov/preservation. 

Caltrans’ Pavement Maintenance Manual. California’s approach to prevention can be downloaded at www.dot.ca.gov/hq/maint/manual/ 

maintman.htm. 

National Center for Pavement Preservation. Visit this 

new group’s site at www.pavementpreservation. 

org/. 

International Slurry Surfacing Association. Browse 

their resources at www.slurry.org. 

Asphalt Emulsion Manufacturers Association. 

Information on emulsions used in chip and slurry seals, both conventional and polymer-modified, may be downloaded at www.aema.org. 

Reprinted from Better Roads, April 2005. Better Roads can be 

visited online at www.BetterRoads.com. 

44 

Archived
A Giant Leap Forward for 

Pavement Preservation 

In October 2003, the National Center for Pavement 

Preservation (NCPP) in Okemos, Michigan, was 

dedicated with the goal of taking pavement preservation to a higher level across the United States. 

More than a year later, the center’s initiatives in support of that goal range from developing new training courses to launching State pooled-fund consortiums to providing one-on-one outreach services to 

highway agencies. “NCPP’s establishment was the 

culmination of a lot of hard work by several organizations and is a milestone signifying a high level of 

cooperation between government and industry to 

benefit the taxpayer,” says Larry Galehouse, NCPP 

Director. “It will lead to better performing roads at 

lower cost.” 

“For pavement preservation, it’s been a giant leap 

forward,” says King Gee, Associate Administrator 

for Infrastructure at the Federal Highway Administration (FHWA). 

The center was founded by Michigan State University, the Foundation for Pavement Preservation, 

and FHWA to lead and coordinate collaborative 

efforts among government, industry, and academia 

to advance pavement preservation. Pavement 

preservation is a program employing a network 

level, long-term strategy that enhances pavement 

performance by using a set of cost-effective practices that extend pavement life. Practices must 

be carefully selected and must be applied before 

the pavement sustains structural damage. “Keeping good roads in good condition has been the 

philosophy that gives a high rate of return for 

the preservation investment,” says Jim Sorenson 

of FHWA. 

The Midwest Pavement Preservation Partnership met November 30–December 1, 2004, in East Lansing, MI. 

45 

Archived
To bolster training efforts nationwide, 

NCPP is offering a new 2-day course for State 

and local agencies, “Pavement Preservation: 

Applied Asset Management.” This course is 

designed to provide transportation officials, 

managers, and practitioners with a comprehensive understanding of pavement preservation. The course covers the components of 

preservation, benefits of undertaking a pavement preservation program, and asset management principles and how they can be used 

to manage highway pavements. Also covered 

are data inventories, pavement distress identification and analysis, network and project 

level management, and pavement preservation strategies. The workshop also features 

hands-on group exercises, where attendees 

can develop network level preservation strategies and select treatments to complement the 

preferred overall strategy. 

A pilot for the course was held in Lansing, 

Michigan, in December 2004. “The pilot was 

very successful, with a lot of interest expressed 

by participants and a lot of positive feedback,” 

says John O’Doherty of NCPP. The Michigan Asset 

Management Council has already scheduled three 

more sessions of the course. 

Additional courses being developed include ones 

on chip seals and ultra-thin hot-mix asphalt overlays 

for practitioners. NCPP also intends to develop a 

course on a variety of treatment activities and one 

on network management for planners and managers. “Education on pavement preservation is needed on several different levels,” notes O’Doherty. “You 

need it for both those in the field doing the work and 

those planning strategies at the network level.” 

Outreach is another important part of NCPP’s 

work. “At the invitation of a State or local agency 

that wants to start a pavement preservation program, we can visit their agency, do a detailed assessment of their pavement practices, and advise them 

on ways to initiate or improve their pavement 

preservation efforts,” says O’Doherty. The center is 

currently working with several State departments of 

transportation to develop preventive maintenance 

guidelines for their agencies and help establish or 

refine pavement preservation programs. 

NCPP is also facilitating State partnerships to 

address pavement preservation issues. With NCPP’s 

help, Midwestern States have formed the new Midwest Pavement Preservation Partnership. This is a 

pooled-fund effort to bring together local and State 

highway agency representatives, contractors, suppliers, and members of academia to share their pavement preservation knowledge and identify and 

sponsor needed research. Additional partnerships 

for the Southeastern, Northeastern, and Western 

States are now being planned. States may join a 

regional partnership through the NCPP at a cost of 

$5,000 per year. 

For more information on NCPP’s resources, 

scheduling the 2-day pavement preservation 

course for your State or region, or joining a regional Pavement Preservation Partnership, contact 

Larry Galehouse at 517-432-8220 (fax: 517­

432-8223; email: galehou3@msu.edu), or visit 

www.pavementpreservation.org. For additional 

information on pavement preservation or technical support, contact Tom Deddens of FHWA’s 

Construction and System Preservation Team, 

202-366-1557 (fax: 202-366-9981; email: tom. 

deddens@fhwa.dot.gov).* 

Reprinted from Focus, March 2005.
 

*The FHWA contact for current information on this topic is 


Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

46 

Archived
Preservation Partnership Promotes 

Preemptive Practice 

by Greg Udelhofen 

Convincing transportation agencies, legislators and 

taxpayers that a “worst first” approach to maintaining the quality and safety of road structures 

throughout the country proved to be an underlying 

theme of presentations and discussions at the recent 

Midwestern Pavement Preservation Partnership 

conference held in East Lansing, MI. Sponsored by 

the National Center for Pavement Preservation, 

MPPP’s mission is to provide pavement preservation 

practitioners (public agencies, contractors, suppliers, 

academia, local and federal government officials) an 

ongoing regional forum to publicize and share information that promotes the benefits of pavement 

preservation. With insufficient funding available to 

address all infrastructure needs, whether it’s new 

construction or maintaining existing roadways, 

preservation plays a vital role in not only maintaining the quality and safety of good road structures, 

but also helps to maximize available funding for 

maintenance, reconstruction and new construction. 

Preservation proponents promote cost-effective 

solutions, both long- and short-range programs, by 

providing “the right fix at the right time in the right 

place.” 

King W. Gee, associate administrator for the Federal Highway Administration’s Office of Infrastructure, told MPPP attendees that managing the 

nation’s 3.9 million miles of roads will require a 

continued preservation approach. In fact, Gee 

issued a Preservation Maintenance Eligibility memorandum (Oct. 8, 2004) to all FHWA directors of 

field services, division administrators and Federal 

Lands Highway Division engineers stating: “The 

FHWA supports increased flexibility for using federal-aid funding for cost-effective preventive maintenance.” The FHWA recognizes that “timely preventive maintenance and preservation activities are 

necessary to ensure proper performance of the 

transportation infrastructure.” 

The memorandum states: “By using lower-cost 

system preservation methods, states can improve 

system conditions, minimize road construction 

impacts on the traveling public, and better manage 

their resources needed for long-term improvements, such as reconstruction or expansion. Preventive maintenance offers state DOTs a way of increasing the return on their infrastructure investment.” 

The American Association of State Highway and 

Transportation Officials (AASHTO) defines preventive maintenance “as the planned strategy of costeffective treatments to an existing roadway system 

and its appurtenances that preserves the system, 

retards future deterioration, and maintains or 

improves the functional condition of the system 

without increasing the structural capacity.” 

According to Gee, the system preservation 

approach is a necessary part of the infrastructure 

solution because it extends the service life of roadways, maximizing the investment, while buying 

some time for long-term solutions. He acknowledged Kansas DOT’s 20-year preservation approach 

and how it has improved the quality of roads 

throughout the state. 

A preservation model 

Jon Rice, P.E., managing director of Kent County 

Road Commission (Grand Rapids, MI), presented 

the approach his agency is taking to implement a 

preservation program that will eventually achieve 

higher levels of system conditions by 2015. 

The Commission implemented its preservation 

program for all county roads in 1999. It also implemented a software program to analyze pavement 

conditions to determine when a preservation 

approach will provide the most value to the life cycle 

of a road. With five years of data collection, Rice 

said that if a road goes from fair condition to very 

poor condition, it will cost four to five times more 

to bring that structure back to fair condition. 

47 

Archived
While Kent County’s road maintenance budget 

has remained constant over the past five years, an 

increase in preservation funds has been made to 

eliminate major rehabilitation expenditures. As the 

Commission evaluates major expansion, construction and reconstruction projects, it also evaluates 

whether or not adequate investments are being 

made to preserve the overall system. On an annual 

basis, it assesses existing and projected conditions of 

its roadways, and forecasts the system’s level impact 

of alternative investment scenarios. 

In 2003, 59 percent of Kent County’s road system 

was in good (maintain) condition, with 27 percent 

in fair condition (requiring preservation) and 14 

percent in poor condition (requiring reconstruction). 

Rice and other preservation proponents know 

that for every $1 spent on preservation to maintain 

a road in fair condition, the investment can jump to 

$4 or $5 if the road is allowed to deteriorate to a 

poor condition; and they also know the drop from 

fair to poor condition happens quickly. 

Rice and the Kent County Road Commission’s 

preservation approach is to apply appropriate 

preservation treatments to roadways that are in 

good or fair condition to preserve the quality of the 

structures, as well as extend the life cycle of the 

structures. Preservation practices currently used in 

Kent County include crack sealing and patching, 

microsurfacing, chip seal, and thin hot mix asphalt 

overlays. 

Since implementing a preservation program, the 

Commission shifted investment dollars from construction/expansion to preservation, and overall 

road conditions have improved significantly. In 

1999, 29 percent of the county’s road system 

required reconstructive work. In 2003, only 13 percent of the county’s system was designated as a 

reconstruction candidate. By 2008, Rice projects 

that only 2 percent of the system will require reconstruction. But what’s more significant about the 

preservation approach being used is that approximately 80 percent of the county’s road system will 

be in good condition and remain in good condition 

for years to come. 

‘Best practices’ 

Currently eight of the proposed 13 Midwestern 

states that were invited to join MPPP have made the 

commitment to do so, and representatives from 

their respective road agencies briefed MPPP conference attendees on their current preservation efforts. 

Some have extensive preservation programs, like 

that of Kansas, while others are in their infancy in 

implementing a preservation approach. 

Minnesota spent $32 million on pavement maintenance in 2004, covering 2,900 lane miles (10 percent of its system) with preservation surface treatments like chip seal and microsurfacing. Michigan 

has established a warranty program to monitor and 

police pavement maintenance contractors working 

on state-funded preservation projects. 

Kansas’ 20-year-old pavement management program continues to evolve as preservation proponents strive to put 72 percent of the state’s road system in good condition. Kansas’ preventive maintenance program is “ride oriented,” which means if a 

preventive maintenance action can improve the ride 

for motorists, then it’s approved. 

Montana’s annual $40 to $50 million preservation budget is let to projects that comply with the 

48 

Archived
state’s DOT’s Guidelines for Nomination and 

Development of Pavement Projects. 

Indiana utilizes its Pavement Management 

Groups to provide a systematic way of recommending, reviewing and approving proposed preservation projects. While the state’s pavement preservation program still requires a lot of work in getting 

local, district and central DOT offices to agree on 

what, when and where the approach makes sense, a 

substantial portion of the state highway construction budget is earmarked for pavement maintenance/preservation. 

North Dakota, on the other hand, is just starting 

to develop an investment strategy that will support 

a preventive maintenance program as a good investment in preserving the state’s infrastructure assets. 

Missouri is still operating in a reactive “worst first” 

mode in maintaining its road system. The DOT is 

currently trying to educate the public, as well as 

internal customers, on the benefits of initiating a 

preventive pavement maintenance program. 

Illinois DOT recently initiated its pavement 

preservation approach by approving 27 project 

locations (three per each of its nine districts) to 

begin evaluating how preservation techniques like 

microsurfacing, chip sealing and slurry sealing 

extend the life cycle of its roads. 

Moving forward 

Through the Transportation Pooled Fund Program 

(TPF), MPPP hopes to develop national protocols 

for pavement preservation and publish those protocols as AASHTO standards to improve the overall 

quality and treatment performance. 

According to Larry Galehouse, NCPP director, 

“two overwhelming issues” were designated as top 

priority by MPPP members. First, MPPP directed 

the NCPP to post on its web site various state specifications regarding preventive maintenance preservation techniques. The hope is to establish some 

standardized preservation practices that will eventually become uniformly accepted by road agencies 

throughout the Midwest and eventually the country. 

Also, once funding has been released from TPF, 

which is sponsored by FHWA, AASHTO and the 

Transportation Research Board, the NCPP will 

begin to collect data on preservation research that 

various states have conducted to this point. The 

intent is to identify duplication of research efforts to 

better identify what type of research needs to be 

done. 

The MPPP will continue to meet on an annual 

basis to discuss and exchange information on sound 

preservation practices, as well as provide training to 

implement successful preservation programs. 

Two other preservation partnerships, one in the 

Northeast and one in the Southeast, are in a formation stage, and Galehouse anticipates the synergies 

to be gained by additional regional groups will benefit the overall objectives of all involved in pavement 

preservation. 

For more information on MPPP, contact 

Larry Galehouse at the National Center for Pavement Preservation, 517-432-8220 or www. 

pavementpreservation.org. 

Reprinted from the Asphalt Contractor, January 2005. 

49 

Archived
DC Streets: Innovation Yields Results
 

In July 2000, the District of Columbia embarked on 

the first urban, performance-based asset management project in the United States, known as “DC 

Streets.” Under the $70 million, 5-year initiative, the 

District of Columbia Department of Transportation 

(DDOT) and the Federal Highway Administration 

(FHWA) contracted with VMS, Inc., to preserve and 

maintain approximately 121 km (75 mi) of roadway 

that make up the District’s portion of the National 

Highway System (NHS). Also included in the contract is the maintenance of such assets as tunnels, 

bridges, curbs, gutters, sidewalks, and retaining 

walls. As the initiative wraps up its fifth and final 

year, stakeholders are reviewing both the successes 

and the lessons learned. 

According to Edward Sheldahl, project delivery 

team leader for FHWA’s DC division office, the contract’s big advantage is that it covers all of the assets 

of the District’s portion of the NHS, which carries 

the bulk of DC traffic. “Before this contract, maintenance of these roadways was the responsibility of 

the city, and suffered because the resources weren’t 

there. Because this contract qualifies for Federal aid, 

it is 80 percent funded by the Federal Government, 

with a 20 percent local match,” says Sheldahl. A 

major highlight of the program, adds Sheldahl, was 

the rehabilitation of two very heavily used tunnels 

in downtown DC that was undertaken as one of the 

initiative’s first priorities. He also notes that the contract ensured the timely repair and replacement of 

peripheral assets such as lighting and guardrails. 

For Rich Herlich, president of VMS, Inc., the 

nature of the initiative itself was the biggest success 

of the project. “This kind of outcome-based contract relies on close cooperation between public and 

private partners,” he says. “We as the contractor 

were given great freedom to choose how to conduct 

routine and preventive maintenance. Overall, the 

process went well.” 

One example of innovation in action was the 

widespread use of spray-injection mobile pothole 

patcher technology for the first time in the District. 

The mobile pothole patcher machines can be used 

to quickly and efficiently fill potholes, minimizing 

the inconvenience to drivers and the exposure of 

work crews to traffic. VMS believed in the technology and used it on the NHS roads. After seeing the 

positive results in terms of fewer driver complaints, 

DDOT has now accepted the technology. “It was 

controversial at first, but that’s the great thing about 

this type of contract,” Herlich explains. “The contractor is free to do innovative things, and if it doesn’t work, we fix it.” 

Simon Rennie, DDOT project manager for DC 

Streets, notes that change can be difficult in public 

agencies, and welcomes the injection of innovation 

that this type of contract allows. According to 

Rennie, the greatest advantage to such a contract is 

the ability to address unforeseen maintenance 

without the need for an additional appropriation 

process and the corresponding delay. For example, 

when Hurricane Isabel struck the District in September 2003, resulting in downed trees and submerged highways, Rennie had already consulted 

with VMS to arrange standby crews to address the 

damage. As a result, the roadways were restored 

within 72 hours, a feat that Rennie does not believe 

would have been possible before the DC Streets initiative was in place. 

Rennie places a high value on this responsiveness 

to emergencies and citizen complaints. “Now, when 

someone calls our office with a report of an asset 

needing repair, I can call VMS, report the problem, 

get the schedule for when it will be fixed, and call 

the citizen back and tell them when the problem will 

be addressed, all in a short time,” he says. 

Despite its successes, the DC Streets program has 

not been without a few lessons learned on how to do 

a better job in future initiatives. According to Mark 

Robinson, program manager for Science Applica50 

Archived
Work performed under the DC Streets contract has included snow removal and clearing trees and other debris 

after Hurricane Isabel hit the city in September 2003. 

tions International Corp. (SAIC), which provided 

management consulting services for the DC Streets 

initiative, the contract has been a success, but some 

of the actual contract language should be adjusted 

in future contracts of this nature. 

“Because this was the first time that such a contract was drafted for an urban area, some of the 

demands it stipulates were not achievable with reasonable effort,” says Robinson. “For example, a few 

of the maintenance categories are still not up to par 

because there is not a well defined line between 

what is rehabilitation, which is covered in the contract, and what is reconstruction, which is not. So 

some actions required to satisfy the performance 

standards fall outside the scope of the contract. 

We’ve resolved these issues through a combination 

of general partnering agreements and item-by-item 

negotiations. Because this is a hybrid of a construction and a services contract, we need to better define 

the rehabilitation/reconstruction criteria in the 

future.” 

Herlich agrees that criteria and definitions need 

to be clarified in future agreements. “Some of the 

standards were contradictory,” he notes. “For example, there is a standard for curb conditions. In some 

cases, tree roots have displaced the curb slabs, and 

the only way to fix this is to remove the trees. But 

another standard says that these trees should be preserved. We resolved the conflict through mediation 

and consultation, and kept the trees.” 

Rennie would like to see language in future contracts tying the meeting of performance standards 

to the incremental payment of the contract. Currently, VMS receives a monthly 

payment regardless of asset conditions. He would also like to see a 

greater sampling of assets to determine if performance standards 

have been met. The current sampling percentage is 10 percent. 

Looking beyond the contract’s completion in 

July 2005, Sheldahl expects the District to opt for 

smaller, follow-on asset management contracts 

focusing on specific types of assets, such as tunnels 

or bridges. He expects to see four to five such contracts, addressing the most vital components of the 

NHS, and possibly expanding to other District 

arteries that are not a part of the NHS. However, 

funding may not be available to issue contracts for 

all of the components of the DC Streets program. 

VMS would pursue a contract similar to DC Streets 

in the future without question, says Herlich, and 

might pursue smaller contracts if they make sense 

for the company. 

“Performance-based contracts, when closely 

monitored, are definitely a good way to go,” adds 

Rennie. 

For more information about the DC Streets initiative, contact Edward Sheldahl at FHWA, 202-219­

3514 (email: edward.sheldahl@fhwa.dot.gov), 

Simon Rennie at DDOT, 202-671-4666 (cell: 202­

438-8607; email: Simon.Rennie@dc.gov), or Mark 

Robinson at SAIC, 703-676-2384 (email: MARK. 

D.ROBINSON@saic.com). 

Reprinted from Focus, December 2004. 

51 

Archived
Preferential Treatment 

by Katie Zimmerman, P.E., and David Peshkin, P.E. 

Today’s transportation agencies face challenges that 

are vastly different than those faced by the previous 

generation. On the one hand, improvements in 

technology have resulted in dramatic changes in the 

tools that are available today for construction, 

design and program development activities. On the 

other hand, public agency staffing and budgets are 

being slashed, there is more competition for available resources and there is growing demand for 

greater accountability for the decisions that are 

made. 

One of the keys to success in this volatile environment lies in being able to make better use of 

technology so that decisions are made faster, recommendations are backed up with factual information 

and trade-offs between investment options can be 

easily evaluated. 

Another key to success is to change the way 

transportation agencies do business. In today’s environment, that means increasing the use of low-cost 

preventive maintenance treatments early in a pavement’s life cycle to slow the rate of pavement deterioration and defer the need for more costly rehabilitation actions. 

Treatment picking 

The selection of an appropriate preventive maintenance treatment for a given set of conditions begins 

with the identification of the treatments to include 

in the program. Agencies vary in their selection of 

treatments, but most agencies include the types of 

treatments listed in Table 1 in their preventive 

maintenance program. Some agencies expand the 

definition of preventive maintenance treatments 

to include cold in-place recycling or hot in-place 

recycling for flexible pavements, and various patching and full-depth repair strategies for rigid pavements. 

Once feasible treatments are identified, then the 

following considerations can be used to determine 

the most appropriate treatment for each situation: 

•	 The purpose of the treatment, including an 

assessment of the pavement conditions that the 

treatment is meant to prevent or correct. For 

example, if moisture is getting into the underlying pavement layers, the purpose is to seal the 

surface. In some cases, there may be more than 

one purpose for applying a treatment, such as 

both sealing the surface and restoring surface 

friction; 

•	 The applicability of each treatment to address 

existing distress, after considering the type, 

severity and extent of distress, current and projected traffic levels and environmental conditions. In some parts of the country it’s appropriate to consider other factors such as the amount 

of snow plowing that is done each winter, the use 

of studded tires or chains, the availability of contractors and the amount of time available for 

lane closures to complete the work; 

•	 Construction considerations, which might 

include the complexity of the construction of the 

treatment, the need for specialized equipment, 

the local availability of qualified contractors and 

the need for specialized materials; 

•	 Performance and cost, which determine the costeffectiveness of the feasible options. In some 

cases, preventive maintenance treatments are 

feasible under a given set of circumstances, but 

are not effective in terms of the level of performance that can be expected. Treatment performance and cost should be considered together to 

differentiate between feasible alternatives for 

reaching similar objectives. Comparing the ratio 

of expected life divided by treatment cost is a 

52 

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quick and easy approach for comparing these Table 1. Types of preventive maintenance techniques. 

variables; and 

•	 Customer satisfaction, which may include characteristics that are important to the traveling 

public, such as noise, smoothness, safety and 

traffic disruptions. 

A decision matrix for taking these factors into 

account in selecting the most appropriate preventive maintenance treatment to match specific project attributes is illustrated in FHWA Publication No. 

FHWA-IR-00-027, Selecting a Preventive Maintenance Treatment for Flexible Pavements (August 

2000) and in the “Participant’s Workbook” for 

National Highway Institute (NHI) Course No. 

1311058, Pavement Preservation: Selecting Pavements for Preventive Maintenance. 

The matrix is fully customizable so that an 

agency can consider whatever considerations are 

most important for the specific project being analyzed. These considerations are included in the table 

as rating factors. A weight is assigned to each rating 

factor to represent the relative importance of each 

in selecting the appropriate treatment. 

For example, if an agency decides that traffic disruption is the most important consideration, it is 

assigned the highest weight among all of the rating 

factors. 

The weights must add up to 100. The final step is 

to score each of the feasible treatments on each rating factor. The product of the scores and weights are 

Bituminous-Surfaced Pavements Concrete-Surfaced Pavements 

Thin hot-mix overlays Crack and joint sealing 

(less than 1.5 to 2 in.) Diamond grinding 

Crack treatments Diamond grooving 

Microsurfacing Undersealing 

Chip seals Load transfer restoration 

Fog seals Maintenance of drainage features 

Slurry seals 

Ultrathin friction course 

Maintenance of drainage features 

Table 2. The effectiveness of preventive maintenance. 

Distress Type Characteristics 

Fatigue Cracking Low severity only; preventive maintenance is not 

appropriate for med-high severity fatigue cracks. 

Longitudinal & Transverse 

Cracking 

Low and medium severities only; a chip seal is 

not appropriate for pavements with wide cracks. 

Bleeding Any amount of bleeding can be addressed with 

a chip seal, but it is most effective on smaller 

quantities. 

Raveling A chip seal is an appropriate treatment for a 

pavement with raveling present. 

Rutting Rutting should not be addressed with a surface 

treatment. summed for each feasible treatment strategy, and 

the treatment with the highest total score is identified as the most appropriate treatment for the given 

conditions. 

To ensure the timely application of the selected 

treatment, many transportation agencies have 

developed pavement preservation guides that provide agency personnel with useful information for 

selecting the appropriate treatment to address a 

given set of conditions. Typically, the guides include 

information on the most commonly observed distress types and their severities, as well as recommendations for preventive maintenance treatments 

that address the specific distress. For example, Table 

2 provides guidance on the types and amount of 

distress that can be reasonably addressed by a chip 

seal. In this example, roads with conditions outside 

the indicated ranges would not be viewed as good 

chip seal candidates. 

An agency’s guidelines should be reviewed regularly to determine whether changes in the agency’s 

practices or policies are influencing the types of 

treatments being considered or the conditions 

under which they are considered. Since industry is 

constantly developing new approaches to pavement 

preservation, new treatments also should be considered for inclusion in the guidelines. 

Seeking advice 

Agencies that have developed guidelines for the use 

of preventive maintenance treatments usually base 

them on observations that have been made by engineers and technicians in the field. But how can an 

agency develop these guidelines if they haven’t used 

the treatments before or if the treatments have only 

been applied as bandages on failed pavements? In 

these situations, an agency must rely on informa53 

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tion published by other agencies with similar conditions, or seek other sources of information on treatment performance. 

One of the most difficult issues to address is the 

appropriate timing for applying preventive maintenance treatments. In many cases, applying a treatment to a new pavement surface is probably using 

preventive maintenance too soon, while waiting 

until the end of the pavement’s life to apply a treatment is too late. However, finding the right time— 

when the treatment is effective and it is not a waste 

of money—is a significant challenge. 

Some agencies have begun monitoring preventive maintenance test sections as one way of determining the effect of treatment timing on performance. 

The Arizona Department of Transportation, for 

example, has constructed test sections with varying 

surface thickness to represent pavements at different 

points in a pavement life cycle (the idea is that the 

thinner roads will deteriorate faster than thicker 

sections so they represent a pavement later in its life 

cycle). Preventive maintenance treatments have 

been applied to these sections and the performance 

of the treatments is being monitored so that guidelines on treatment timing can be developed. 

Nationally, a study conducted under the National Cooperative Highway Research Program 

(NCHRP) found that there is little guidance available to agencies regarding the optimal time to apply 

preventive maintenance treatments. Because of the 

lack of available information on this topic, the study 

focused on the development of a tool that could be 

used to identify the window during which the greatest improvement in pavement condition is realized 

for the lowest cost. 

In concept, the methodology for identifying the 

optimal timing is relatively simple. However, the 

application of the methodology can be complex 

without appropriate tools. A spreadsheet tool was 

developed to assist agencies with analyzing their 

preventive maintenance-related data. As part of the 

study it was tested in several state highway agencies. 

One of the agencies included in the study was the 

Kansas Department of Transportation (KDOT). 

KDOT is in the process of developing prediction 

models that reflect the influence of preventive 

maintenance treatments for its pavement management system. Using KDOT’s transverse crack models, the NCHRP tool (referred to as OPTime) was 

used to determine the optimal time to rout and seal 

cracks on a flexible pavement. The analysis showed 

that under the conditions modeled, it was most 

cost-effective to rout and seal cracks when the pavement is 11 years old. 

Another example using data from the North 

Carolina Department of Transportation found that 

a seal coat was most cost-effective when applied 

nine years after resurfacing or reconstruction. It is 

worth noting that these results are very dependent 

on the inputs used in the analysis and should not be 

used by other agencies without modification. 

Seeking a management position 

Fundamental to applying the right treatment at the 

right time is the ability to forecast when the conditions are appropriate for applying a preventive 

maintenance treatment and making sure that the 

resources are available to construct the treatment 

then. A pavement management system can assist 

with these analyses as long as the preventive maintenance treatments are included in the treatments 

being considered. 

Pavement management systems have been used 

for years to help agencies identify and prioritize 

pavement improvement needs, determine funding 

levels needed to meet certain pavement condition 

objectives and to project network conditions under 

various funding scenarios. In recent years, some 

agencies have used their pavement management 

systems to demonstrate the cost-effectiveness of 

preventive maintenance programs as a way of securing the funding needed to jump-start their preservation programs. As agencies increasingly consider 

the use of preventive maintenance treatments as a 

pavement preservation strategy, challenges are 

emerging associated with the integration of preventive maintenance treatments into a pavement management system. For the most part, these difficulties 

are arising because the pavement management system was originally structured to focus primarily on 

rehabilitation and reconstruction activities. 

The inclusion of preventive maintenance treatments requires agencies to re-evaluate their pavement management procedures to ensure that the 

factors that trigger the use of preventive maintenance treatments are incorporated into the pavement condition survey procedures and are available 

in the database, that the performance of a preventive maintenance treatment can be effectively modeled and that treatments that have been constructed 

are reflected in the database and in future analyses. 

These activities are not always as easy as they appear. 

54 

Archived
For instance, fog seals may be considered to 

address pavements that have cracking, low friction 

numbers or oxidation. Most pavement management 

condition surveys do not include friction or oxidation, so these treatment triggers are not available in 

the pavement management database to trigger the 

use of a fog seal. 

Other features that might be important to trigger 

preventive maintenance treatments include fine 

cracking or the differentiation between sealed and 

unsealed cracks. 

Perhaps more complicated is the modeling of 

preventive maintenance treatments in a pavement 

management system. To appropriately match feasible treatments with pavement conditions, the pavement management system must be able to predict 

the changes in pavement condition with time. This 

implies that the performance of pavement sections 

can be differentiated when preventive maintenance 

treatments are applied so that the benefit associated 

with the treatment can be calculated. It also requires 

that rules exist to identify the appropriate performance curve for each pavement section. If an agency’s 

pavement management system includes only 

asphalt and concrete surface types, for example, it 

will be difficult for that agency to identify different 

performance models for each of its preventive 

maintenance treatments. 

Although the integration of preventive maintenance treatments into an agency’s pavement management system may not be as simple as it first 

appears, there are steps that an agency can take to 

improve its consideration of preventive maintenance treatments in its pavement management system. An agency can start by establishing a single 

treatment in its decision trees that represents the 

broad category of preventive maintenance treatments and is triggered on roads that are in good 

condition. Over time, more sophisticated models 

can be developed. 

our stewardship of our transportation infrastructures. More and more highway agencies are using 

preventive maintenance as a way to face these constraints head-on. 

When properly used—that is, when an appropriate treatment is used on a pavement that is in good 

condition—preventive maintenance helps to extend 

the life of the pavement structure, delaying the need 

for more extensive and costly rehabilitation and 

improving other desirable characteristics, such as 

safety and smoothness. 

There are several factors that are key to successful preventive maintenance programs. These 

include identifying the mix of treatments that will 

provide the desired benefits for your pavements and 

developing guidelines for when those treatments 

should be used to obtain the greatest benefit. A 

recently completed NCHRP project on the optimal 

timing of preventive maintenance treatments offers 

guidance on these topics. A spreadsheet tool also is 

available to help in the analysis of treatment timing. 

It’s also important to remember that pavement 

management tools and systems can be extremely 

valuable in the successful implementation of preventive maintenance practices. The integration of 

preventive maintenance into a working pavement 

management system can help to identify pavements 

which are good preventive maintenance candidates 

and monitor their performance once the treatments 

have been applied. Pavement management systems 

also can be used to identify preventive maintenance 

funding needs and to illustrate cost-effectiveness. 

The use of preventive maintenance treatments is 

an integral part of a cost-effective pavement preservation program. Employing preventive maintenance treatments effectively enables an agency to do 

more with less, thereby making cost-effective use of 

the available resources as part of a coordinated program to improve the serviceability of its road network. 

Zimmerman is president of Applied Pavement Technology, Facing success Champaign, Ill. Peshkin is vice president of AP Tech, Chicago. 

Even in the face of increasing constraints, such as Reprinted from Roads & Bridges, June 2004. smaller budgets, reductions in staff and greater 

accountability, there are opportunities to improve 

55 

Archived
Pavement Preservation Resources 

Offer “How-To” Guidance 

Learn more about pavement preservation practices 

that are working nationwide by consulting the many 

new resources, ranging from guidance checklists to 

CDs, available from the Federal Highway Administration (FHWA). 

Two new CDs produced by FHWA and the Foundation for Pavement Preservation (FP2) look at 

pavement preservation in action across the country. The first CD, Pavement Preservation 2: State of 

the Practice, contains policies, guidance, and technical information from California, Delaware, 

Michigan, Minnesota, Montana, North Carolina, 

Ohio, and South Dakota. The CD provides a 

range of information, from guidelines for 

statewide preservation programs to examples of 

innovative funding approaches. Also included are 

“how-to” technical manuals and details on training courses, videos, fact sheets, and other useful 

resources. 

National Pavement Preservation Forum II: Investing in the Future (Publication No. FHWA-IF-03­

019), meanwhile, includes papers and presentations 

from the 2001 Forum hosted by the California 

Department of Transportation and FP2 in San 

Diego, California. The CD covers such topics as introducing new pavement preservation products and 

techniques, establishing partnerships, integrating 

pavement preservation into pavement management 

systems, and performing education and outreach. 

For step-by-step guidance on the use of innovative pavement preventive maintenance processes, 

turn to FHWA’s and FP2’s 

series of pavement preservation checklists. Topics Pavement Preservation Online Resources 

FHWA—www.fhwa.dot.gov/preservation 

Foundation for Pavement Preservation—www.fp2.org 

National Center for Pavement Preservation— 

www.pavementpreservation.org 

56 

in the series to date are: 

• Crack Seal Application 

(Publication No. 

FHWA-IF-02-005) 

•	 Chip Seal Application (Publication No. FHWAIF-02-046) 

•	 Thin Hot-Mix Asphalt Overlay (Publication 

No. FHWA-IF-02-049) 

•	 Fog Seal Application (Publication No. FHWAIF-03-001) 

•	 Microsurfacing Application (Publication No. 

FHWA-IF-03-002) 

•	 Joint Sealing of Portland Cement Concrete Pavements (Publication No. FHWA-IF-03-003) 

The checklists take users through such steps as 

project review, material checks, surface preparation, 

equipment inspections, weather requirements, and 

common problems and solutions. 

For information on the scope of pavement 

preservation activities underway in States from California to Michigan to North Carolina, consult 

FHWA’s Pavement Preservation Compendium (Publication No. FHWA-IF-03-21), which presents articles, 

papers, and other reference material on accomplishments to date and future needs. The Compendium 

also highlights the importance of taking research on 

innovative and effective system preservation technologies to a higher level. To date, research has 

lagged behind the demand for knowledge. 

To obtain copies of the CDs, checklists, or Compendium, contact Steve Mueller in FHWA’s Office 

of Asset Management, 202-366-1557 (email: steve. 

mueller@fhwa.dot.gov),* the National Center for 

Pavement Preservation at 517-432-8220 (email: 

hahnp@egr.msu.edu), or your local FHWA Division 

Office. For additional information on pavement 

preservation, visit the Web sites listed in the sidebar. 

Reprinted from Focus, March 2004. 


*The FHWA contact for copies of resources or current information
 

on this topic is Joe Gregory, 202-366-1557 (email: joseph. 

gregory@dot.gov). 

Archived
Resources for a Better Future 

by Jim Sorenson 

With more than $1.75 trillion invested in the technical assistance and work with highway agencies 

nation’s highway system, preserving that investment and others on meeting training and education needs. 

is one of today’s key challenges facing both state and The center’s resources include a technical library of 

local highway agencies across the country. To meet national studies, specifications and treatment procethat challenge, agencies can now call upon a range dures. The center is now providing technical services 

of new pavement preservation resources. Pavement to several state and local agencies. To learn more 

preservation is applied asset management. It is the about the NCPP and the assistance it can provide 

planned strategy of treating pavements at the opti- look online at www.pavementpreservation.org. 

mum time to maximize their useful life, enhancing Two new CDs available from FHWA and FP2 

pavement longevity while lowering lifetime costs. also provide a wealth of information on pavement 

Preserving our pavements also results in increased preservation practices that are working nationwide. 

safety and higher user satisfaction. The first CD, Pavement Preservation 2: State of the 

Preservation treatments are not the right fix for Practice, presents policies, guidance and technical 

every road at any time. Treatments must be careful- information from California, Delaware, Michigan, 

ly selected and must be applied when the pavement Minnesota, Montana, North Carolina, Ohio and 

is still in relatively good condition, that is with no South Dakota. This information ranges from guidestructural damage. Pavement preservation treat- lines for statewide preservation programs to examments are generally lower-cost surface improve- ples of innovative funding approaches. The second 

ments and they offer little or no structural enhance- CD, National Pavement Preservation Forum II: 

ment. They do, however, rejuvenate the roadway Investing in the Future, contains papers and presensurface by addressing the effects of environmental tations from the 2001 forum hosted by the Califoraging and minor surface defects 

before the road deteriorates further and requires rehabilitation or 

reconstruction, which is much 

more costly and time consuming. 

A significant new resource for 

highway agencies is the National 

Center for Pavement Preservation 

(NCPP), which was dedicated at 

Michigan State University in Okemos, Mich., in October 2003. 

Founded by MSU, the Foundation 

for Pavement Preservation (FP2) 

and the Federal Highway Administration (FHWA), the center will 

coordinate, administer and conduct fundamental and applied 

research on pavement preservation. It also will provide hands-on 

nia Transportation Department 

and FP2 in San Diego. The forum 

Pavement 

preservation is 

applied asset 

management. It is 

the planned strategy 

of treating pavements 

at the optimum time 

to maximize their 

useful life, enhancing 

pavement longevity 

while lowering 

lifetime costs. 

was conducted over a pair of twoday sessions, drawing nearly 200 

participants to each session. The 

documents on the CD cover such 

topics as introducing new pavement preservation products and 

techniques, establishing partnerships, integrating pavement 

preservation into pavement management systems and performing 

education and outreach. 

To learn more about the many 

facets of pavement preservation 

activities under way in the U.S. 

today, consult FHWA’s Pavement 

Preservation Compendium, which 

presents a range of articles and 

57 

Archived
other reference material on accomplishments to date • Fog seal application; 

• 	Microsurfacing application; and 

• 	 Joint sealing of portland cement concrete 

pavements. 

To obtain copies of the CDs, checklists or com

pendium, contact Steve Mueller at FHWA, 202/366

1557; e-mail: steve.mueller@fhwa.dot.gov.* 

Sorenson is a senior highway engineer in FHWA’s Office of 

Asset Management. 

Reprinted from Roads & Bridges, February 2004. 

*The FHWA contact for current information on this topic is 

Joe Gregory, 202-366-1557 (email: joseph.gregory@dot.gov). 

and future needs. One such need is to take research 

into effective system preservation technologies to a 

higher level. In this program area, research has not 

kept up with the demand for knowledge. 

Also available from FHWA and its industry partner, FP2, are a series of pavement preservation 

checklists that provide step-by-step guidance on the 

use of innovative pavement preventive maintenance 

processes. Topics covered in the series to date are: 

• 	 Crack seal application; 

• 	 Chip seal application; 

• 	 Thin hot-mix asphalt overlay; 

­

­

58 

Archived
Application of a preventive 

Condition maintenance treatment 

Rehabilitation 

Trigger 

Length of time rehabilitation
 

is deferred
 

Time or Traffic 

Deferred need for 

rehabilitation 

Original need for 

rehabilitation 

The Seven Stallers 

by Katie Zimmerman, P.E. and David Peshkin, P.E. 

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 objective basis; 

•	 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 these 

programs. 

Figure 1. Use of 

preventive maintenance treatments 

to defer the need 

for rehabilitation. 

59 

Archived
 

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 condition. 

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 

Figure 2. Impact of 

two preservation 

strategies on 

overall network 

conditions. 

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 shown 

below: 

•	 Crack filling or crack sealing; 

•	 Joint resealing; 

•	 Surface treatments such as fog seals, sand seals 

and chip seals; 

•	 Slurry seals and microsurfacing; 

•	 Thin hot-mix asphalt (HMA) overlays; 

•	 Diamond grinding; 

•	 Undersealing; 

•	 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 

86 

84 

82 

80 

78 

76 

74 

72 

70 

0 5 10 15 20

Year 

Pavement Condition 

Rating

Average Pavement Condition Over Time 

Worst First Pavement Preservation With Preventive Maintenance 

60 

Archived
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 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. 

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 provided. 

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. 

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 

Figure 3. 

Expenditure 

stream diagram 

for Strategy A. 

Figure 4. 

Expenditure 

stream diagram 

for Strategy B. 

$400,000 

Initial Cost 

$80,000 

Periodic Costs 

Annual Maintenance Costs of $500 

Time (years) 

$40,000 

Salvage 

Initial Cost 

$12,000 Periodic Costs Annual Maintenance Costs of $800 

Time (years) 

61 

Archived
 

 

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. 

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. 

Decision-makers will never support this 

type of program. 

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 maintenance department. 

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 

Figure 5. Present worth values associated with 

each strategy. 

Present Worth of Strategy A 

PW (initial) =$400,000 

PW (routine maintenance) =$ 6,567 

PW (treatment 1) =$ 58,455 

PW (treatment 2) =$ 42,713 

PW (salvage value) =$ -18,255 

Total PW =$489,480 

Present Worth of Strategy B 

PW (initial) =$400,000 

PW (routine maintenance) =$ 10,507 

PW (all four treatments) =$ 32,928 

PW (salvage value) =$ 00 

Total PW =$443,435 

62 

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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 roads. 

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. 

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. 

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. 

Support groups 

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, 

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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 www.nhi.fhwa. 

dot.gov. 

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 www.pavementpreservation.org. 

Reprinted from Roads & Bridges, December 2003. 

64 

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National Center for Pavement Preservation 

Opens in Michigan 

A new era for pavement preservation in the United 

States began on October 17, when the National 

Center for Pavement Preservation (NCPP) was dedicated at Michigan State University (MSU) in Okemos, Michigan. “The National Center for Pavement 

Preservation is a first and the only one in the world,” 

said Bill Ballou, president of the Foundation for 

Pavement Preservation (FP2). “Over the coming 

years, this center will have the opportunity to reach 

each transportation owner agency with technical 

support for pavement preservation programs.” 

The center was founded by MSU, FP2, and the 

Federal Highway Administration (FHWA) to lead 

and coordinate collaborative efforts among government, industry, and academia to advance pavement 

preservation. Pavement preservation is a planned 

strategy of treating pavements at the optimum time 

to maximize their useful life, enhancing pavement 

longevity while lowering lifetime costs. The key to 

successful pavement preservation efforts is applying 

the right treatment to the right pavement at the 

right time. Treatments must be carefully selected 

and must be applied when the pavement is still in 

good condition, i.e., with no structural damage. 

“The Nation’s highways are valued at more than 

$1.75 trillion. As responsible stewards of the highway system, present and future generations cannot 

allow this investment to deteriorate,” said King W. 

Gee, FHWA Associate Administrator for Infrastructure, at the dedication. “The FHWA has undertaken 

a greater focus on preservation philosophy to 

address the significant deterioration that has been 

occurring to the Nation’s infrastructure. Preservation extends highway service life and provides 

smoother, safer, and more reliable roads.” 

The center will coordinate and 

administer fundamental and applied 

research on pavement preservation. It 

will also provide hands-on technical 

assistance and work with highway agencies 

and others on meeting training and education 

needs. The center’s resources include a technical 

library of national studies, specifications, and treatment procedures. 

“The opening of the NCPP brings together the 

resources for national level research and development in the preservation area,” said Jim Sorenson, 

senior construction and system preservation engiParticipating in the October 17, 2003, ribbon cutting for the National Center for Pavement 

Preservation are, from left, Center Advisory Board chair James S. Moulthrop, Fugro-BRE, 

Inc.; King W. Gee, Associate Administrator for Infrastructure, FHWA; Lou Anna K. Simon, 

Provost and Vice President of Academic Affairs, MSU; David Porteous, MSU Board of 

Trustees; Bill Ballou, President, FP2; Rep. Rick Johnson, Michigan Speaker of the House; 

Ronald Harichandran, Chair, Department of Civil and Environmental Engineering, MSU; 

and Janie Fouke, Dean, College of Engineering, MSU. 

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“The National Center 

for Pavement 

Preservation is 

a first and the only 

one in the world. 

Over the coming 

years, this center will 

have the opportunity 

to reach each 

transportation owner 

agency with technical 

support for pavement 

preservation 

programs.” 

neer in FHWA’s Office of Asset Management. The center has the long-term 

potential to help highway agencies at all levels support their pavement infrastructure investment, noted NCPP Director Larry Galehouse. “We will assist 

agencies in becoming more proactive and less reactive when addressing pavement needs, resulting in greater cost savings and satisfaction for the motorist,” 

said Galehouse. 

A Center Advisory Board will serve as a link between the NCPP and the 

pavement preservation community and will help determine priorities and 

direction for the center. For a list of board members, see sidebar. 

For more information about the center and the assistance it can provide, 

contact Larry Galehouse at NCPP, 517-432-8220 (fax: 517-432-8223; email: 

ncpp@egr.msu.edu) or visit www.pavementpreservation.org. 

Reprinted from Focus, November 2003. 

National Center for Pavement Preservation Advisory Board 

•	 James S. Moulthrop, Senior Engineer, Fugro-BRE, Inc. (Chair) 

•	 King W. Gee, Associate Administrator for Infrastructure, FHWA 

•	 Gloria Jeff, Director, Michigan Department of Transportation 

•	 Rick Johnson, Speaker of the House, Michigan Legislature 

•	 Mike Buckingham, President, Strawser, Inc. 

•	 Gerry Eller, Principal, GLE Services 

•	 Jon Epps, Engineering Services Manager, Granite Construction, Inc. 

•	 Ronald Harichandran, Chair, 

Department of Civil and Environmental Engineering, MSU 

•	 Jean-Claude Roffe, Executive Manager, SIR/COLAS 

•	 Bill Temple, Chief Engineer, Louisiana Department of Transportation and Development 

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Principles of Pavement Preservation 

Definitions, Benefits, Issues, and Barriers 

by Larry Galehouse, James S. Moulthrop, and R. Gary Hicks 

Americans are accustomed to easy mobility on safe, 

smooth, and well-maintained roads. These same 

roads play a critical role in the nation’s economy, 

bolstering agriculture, industry, commerce, and 

recreation. 

During the 1990s, the nation’s highways experienced a 29 percent increase in use, and growth is 

expected in the next 10 years. Large commercial 

truck traffic increased by nearly 40 percent, with 

growth projected to continue at more than 3 percent per year during the next 20 years. In addition, 

more than 95 percent of personal travel is by automobile. 

Increasing the capacity of highways, therefore, is 

important in meeting the nation’s needs. But can 

the United States finance future highway capacity 

while addressing the needs of the current system? 

Yes—by developing a strategic plan that includes 

pavement preservation. 

Economical Alternative 

Pavement preservation gives highway agencies an 

economical alternative for addressing pavement 

needs. Moreover, with pavement preservation, highway agencies gain the ability to improve pavement 

conditions and extend pavement life and performance without increasing expenditures. The focus is 

on preserving the pavement asset while maximizing 

the economic efficiency of the investment. Pavement preservation provides greater value to the 

highway system and improves the satisfaction of 

highway users. 

Pavement preservation is not about a single 

treatment, nor is it a one-size-fits-all philosophy. 

Instead, pavement preservation must be tailored to 

each highway agency’s system needs in the most 

cost-effective manner. This involves using a variety 

of treatments and pavement repairs to extend pavement life. 

According to the Federal Highway Administration (FHWA), the United States maintains nearly 

3.95 million miles of public roads.1 Table 1 shows 

highway mileage by agency ownership. The problem facing highway agencies is that many roads are 

wearing out because of increased traffic, environment effects, and a lack of proper maintenance. 

Every highway agency must deal with the effects 

of regional environments on pavement performance, in addition to the effects of traffic. Pavement 

sections originally projected to last many years can 

accumulate distress at an accelerated rate and fail 

prematurely. Most highway agencies experience and 

understand this problem but are daunted when 

budget allocations do not keep pace with the needs 

of highway pavement upkeep. 

Toolbox Approach 

In the past, many maintenance practices have not 

been effective, because they were applied reactively 

to roads in poor condition instead of proactively to 

roads still in good condition. Succinctly stated, the 

correct approach to preventive maintenance is to 

“place the right treatment on the right road at the 

right time.” 

Preservation became a topic in the early 1990s, 

when highway agencies examined effective mainteTable 1. Public highway ownership by miles. 

Jurisdiction Miles (Thousands) Percentage 

Federal 118 3.0 

States 775 19.6 

Local 3,055 77.4 

Total 3,948 100.0 

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Archived
nance practices. The preservation 

concept—whether for pavements 

or for bridges—is a departure 

from traditional approaches, 

which wait until deficiencies are 

evident and until reconstruction 

or major rehabilitation are the only 

means to correct the problem. 

Preservation, however, addresses minor deficiencies early, before 

the defects become major problems, and extends the life of the 

asset at a relatively low cost. A 

strong preservation program is 

essential to asset management. 

Because preservation activities 

include so many kinds of treatments, agencies should build 

their own preservation toolboxes 

to serve their particular needs. 

Just as a mechanic’s toolbox contains many different tools, each 

designed for a specific job, a 

preservation toolbox should 

include a host of treatments to 

address specific conditions. 

No treatment will be suitable for every location. 

For example, a chip seal may be a long-lasting, costeffective surface treatment in a rural area, but not 

in a large urban area. Conversely, concrete ultrathin 

whitetopping may be cost-effective in a large urban 

area, but not in a rural area. Similarly, performance 

and cost-effectiveness should be evaluated in the 

context of the areas in which the preservation treatments are applied. 

Definition of Terms 

A clear presentation of pavement preservation in 

the United States requires the development and 

adoption of standard definitions: 

Asset Management 

FHWA and the American Association of State 

Highway and Transportation Officials (AASHTO) 

define asset management as a systematic process of 

maintaining, upgrading, and operating physical 

assets cost-effectively.2 Asset management combines engineering principles with sound business 

practices and economic theory and provides tools 

to facilitate an organized, logical approach to deciPavement 

preservation gives 

highway agencies 

an economical 

alternative for 

addressing pavement 

needs. Moreover, 

with pavement 

preservation, highway 

agencies gain the 

ability to improve 

pavement conditions 

and extend pavement 

life and performance 

without increasing 

expenditures. 

sion-making. Asset management 

provides a framework for both 

short- and long-range planning. 

Asset management is important to state and local governments because of the Governmental Accounting Standards Board’s 

(GASB) Policy Statement 34, 

“Basic Financial Statements for 

State and Local Governments,” 

issued in June 1999. GASB 34 

encourages government agencies 

to promote asset management 

practices and to report the value of 

capital assets such as utilities, roadways, and other infrastructure.3 

The value and maintenance of 

these assets eventually affects the 

bond ratings of government agencies, which in turn affect the government’s ability to borrow the 

money to repair and replace the 

investments. The objective of an 

asset management program, 

therefore, is to 

•	 Consider various investment strategies, 

•	 Provide a more rational decision process, and 

•	 Improve the overall condition of the highway 

system at a lower cost. 

Preventive Maintenance 

According to AASHTO, preventive maintenance is a 

planned strategy of cost-effective treatments that 

preserves and maintains or improves a roadway system and its appurtenances and retards deterioration, but without substantially increasing structural 

capacity.3 Preventive maintenance is a tool for pavement preservation—nonstructural treatments are 

applied early in the life of a pavement to prevent 

deterioration. In other words, preventive maintenance applies the right treatment to the right pavement at the right time. 

Pavement Preservation 

Pavement preservation is the sum of all the activities 

to provide and maintain serviceable roadways, 

including corrective and preventive maintenance, as 

well as minor rehabilitation. The strategy does not 

include new pavements or pavements that require 

major rehabilitation or reconstruction. 

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Archived
Optimal Timing 

Pavement Condition

Preventive
 

Trigger
 

Rehabilitation 

Original Pavement

Trigger 

Time/Traffic

A pavement preservation program aims at preserving investment in the pavement network, 

extending pavement life, enhancing pavement performance, ensuring cost-effectiveness, and reducing 

user delays. In short, the goal is to meet customer 

needs. 

Reactive Maintenance 

Reactive maintenance comprises activities that 

respond to conditions beyond an agency’s control— 

–activities such as pothole patching, rut filling, or 

unplugging drainage facilities. Reactive maintenance, therefore, is unscheduled; sometimes immediate response is necessary, to avoid serious consequences. 

Emergency Maintenance 

Extreme conditions, when life and property are at 

risk, require emergency maintenance. Examples 

include washouts, rigid pavement blowups (the 

shattering or upward buckling of concrete slabs 

along a joint), and rockslides or earthslides. 

Establishing Values 

Understanding the costs and benefits of pavement 

preservation is important because the nation’s highway system has matured—that is, the system has 

begun to deteriorate. Preservation requires a customer-focused program to provide and maintain 

serviceable roadways cost-effectively, encompassing 

preventive and corrective maintenance, as well as 

minor rehabilitation (Figure 1). 

The concept is gaining acceptance—initiatives 

in the business arena also are focusing on asset 

preservation, like the GASB policy emphasizing the 

preservation of infrastructure. GASB establishes 

requirements for the annual financial reports of 

state and local governments. Since June 1999, 

GASB 34 has required state and local agencies to 

provide more specific information in annual financial statements, following the model of the reports 

by private-sector companies and governmental 

utilities. 

GASB recommends that state, county, and city 

government agencies apply historical costs to establish values for the transportation infrastructure. 

Agencies must identify the annual cost of maintaining and preserving the infrastructure assets 

at—or above—an established condition level. Pavement preservation, therefore, becomes integral to 

investment decision-making at highway agencies. 

Describing the Benefits 

The benefits of implementing a pavement preservation program are not immediate and dramatic but 

accrue over time. Roads that generally are in good 

condition do not register a major change in condition rating after a treatment is applied—the rating 

continues as good. What is important, however, is 

the condition rating several years later—roads that 

receive preservation treatments are in better condition than those left without treatments. 

A comparison of the project life-cycle costs of 

identical pavement sections with and without treatments illustrates the benefits of pavement preservation. In the example of a traditional alternative, 

shown in Table 2, a highway is constructed for 

$508,000 per lane-mile to last 25 years without any 

Figure 1. Pavement 

preservation 

concept. 

69 

Archived
Table 2. Traditional alternative: Project life cycle cost. 

ACTIVITY D.I. 

(Before) 

D.I. 

(After) 

AGE LIFE EXTENDED 

(Years) 

R.S.L. 

(Years) 

COST 

(Lane-Mile) COMMENTS 

New Construction 0 0 25 $508,000 

$ 21,000 

Construction cost 

User cost 

Major 

Construction 51 0 25 25 $490,000 

$ 19,000 

Construction cost 

User cost 

Total $998,000 

$ 40,000 

Construction cost 

User cost 

D.I. = distress index, a measure of pavement condition. Scale values: 0 = no distress, 50 = reconstruction required. 

R.S.L. = remaining service life, the remaining time in which a pavement can be preserved. 

Table 3. Preservation alternative: Project life cycle cost. 

ACTIVITY D.I. 

(Before) 

D.I. 

(After) 

AGE LIFE EXTENDED 

(Years) 

R.S.L. 

(Years) 

COST 

(Lane-Mile) COMMENTS 

New Construction 0 0 25 $508,000 

$21,000 

Construction cost 

User cost 

First Preservation 11 6 5 2 22 $15,000 

$350 

Construction cost 

User cost 

Second Preservation 21 0 10 8 25 $39,500 

$350 

Construction cost 

User cost 

Third Preservation 16 8 14 1 22 $15,000 

$350 

Construction cost 

User cost 

Fourth Preservation 33 0 20 5 21 $55,500 

$700 

Construction cost 

User cost 

Fifth Preservation 14 7 25 2 18 $15,000 

$350 

Construction cost 

User cost 

Total $648,000 

$23,100 

Construction cost 

User cost 

D.I. = distress index, a measure of pavement condition. Scale values: 0 = no distress, 50 = reconstruction required. 

R.S.L. = remaining service life, the remaining time in which a pavement can be preserved. 

preservation activity. After 25 years, the highway 

must be completely reconstructed at a cost of 

$490,000 per lane-mile. 

In the preservation alternative, shown in Table 3, 

a highway is constructed with a 25-year design life, 

also at a cost of $508,000 per lane-mile. After 5 

years, the first short-term preservation action is performed for $15,000 per lane-mile, extending the 

pavement life 2 years. A second preservation is 

applied 10 years after initial construction—a different treatment that costs $39,500 per lane-mile but 

that extends the pavement life an additional 8 years. 

A third preservation is applied in Year 14, a fourth in 

Year 20, and another in Year 25. 

The preservation alternative offers potential savings in construction. In the traditional alternative, 

the pavement must be completely reconstructed 

after 25 years at a cost of $490,000 per lane-mile to 

extend the expected service life another 25 years. In 

contrast, preservation treatments cost $140,000 per 

lane-mile over 25 years and extend the expected 

service life another 18 years. Moreover, if the deterioration rate does not accelerate, pavement preservation can continue for more cycles, assuming that the 

pavement was designed and constructed properly. 

Considering the user costs shown in the tables, 

additional savings will accrue. As shown in Figure 2, 

substantial savings can accrue with a well-planned 

pavement preservation program. 

70 

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PCI 

100 

20 

Excellent 

Good 

Fair 

Poor 

Very Poor 

Failed 

0 5 10 15 20 

75% of Life 

40% Drop in Quality Spending $1 on 

preservation here... 

...eliminates or delays 

spending $6 to $10 

on rehabilitation or 

reconstruction here. 40% Drop in Quality 

12% of Life 

Figure 2. 

Determine 

needs 

Provide framework 

for 

treatment selection 

Develop analysis procedure 

Establish program guidelines 

Provide a feedback loop to determine effectiveness 

Essentials for Success 

Pavement preservation is not a maintenance program, but an agency program. Almost every part of 

an agency should be involved. Success depends on 

support and input from staff in planning, finance, 

design, construction, materials, and maintenance. 

Two other essentials for an effective program are 

long-term commitment from agency leadership and 

a dedicated annual budget. 

Pavement option 

curve (example). 

(PCI = Pavement 

Condition Index.) 

Figure 3. Pavement 

preservation 

process. 

Agency personnel must address many critical 

issues before implementing a pavement preservation program. For example, terminology must be 

defined clearly and concepts such as cost-effectiveness, optimal timing, and pavement performance 

should be understood. Integrating pavement management with pavement preservation, to maximize 

the benefits to the highway network, also is imperative. In addition, agency personnel should be 

instructed about each preservation treatment and 

its appropriate use. 

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Archived
After preparing the groundwork, the next step is 

to tailor a program that meets agency needs. People 

with a thorough understanding of pavement engineering should develop preservation guidelines that 

relate to various pavement conditions, the purpose 

and limitations of each treatment, and the expected 

performance. The guidelines will assist in treatment 

selection and program assessment. 

A good preservation program should establish 

continual monitoring to assure effective feedback 

for improvement of the guidelines. A process model 

is shown in Figure 3. 

Issues and Barriers 

Several issues and barriers may arise as an agency 

develops and implements a pavement preservation 

program. The issues and barriers, however, vary for 

each group involved. 

Institutional Changes 

Some of the issues and barriers from the transportation agency point of view may include the following: 

•	 Identifying a champion for the program. Like any 

new effort or program within an agency, pavement preservation needs a champion. Without a 

champion to promote the importance and benefits, the new effort will not succeed. 

•	 Dealing with the paradigm shift from worst-first to 

best-first. One of the biggest obstacles is convincing agency personnel to move from the triedand-true practice of fixing the worst pavement 

problems first to fixing good pavements while 

the bad ones continue to deteriorate. 

•	 Gaining commitment from the top management. 

The program’s success requires top management 

commitment. This includes a commitment for 

dedicated funding and for the resources needed 

to collect information on the effectiveness of preventive maintenance treatments. Pavement 

preservation projects will not warrant ribboncutting ceremonies—unless the top management recognizes the program’s importance. 

•	 Showing early benefits. Pavement management 

systems that can show the early effects of the preventive maintenance treatments on extending 

life or on reducing life-cycle costs are essential. 

•	 Selecting the right treatment for the right pavement at the right time. Failure can result if the 

correct treatment is not used. For a new program, a single failure can overshadow hundreds 

of successes. The right treatment must be applied 

to the pavement in a timely manner. 

Marketplace Pressures 

The issues and barriers for industry groups mostly 

involve reluctance to disturb the status quo and 

include the following: 

•	 Competition between the suppliers of maintenance 

and rehabilitation treatments. With the shift from 

the traditional rehabilitation programs of pavement overlays applied every 10 to 20 years to 

pavement preservation programs using new or 

different treatments, resistance can be expected 

from the suppliers of traditional rehabilitation 

materials. For example, hot-mix suppliers will 

resist new cold-mix treatments because of the 

likely loss in market share. 

•	 Competition between various suppliers of maintenance treatments. When markets have been 

established for certain types of treatments and a 

new treatment type is being introduced, industry 

often works to block the new products, whether 

for technical reasons or for business reasons, 

again to avoid loss of market share. 

•	 Political lobbying to prevent use of new maintenance treatments. In some cases, industry will 

rely on political lobbying to prevent new technologies from entering the market. Again the 

reasons may be technical but more likely are 

related to the effect on the market if an agency 

adopts the new technology. 

•	 Establishing the benefits of new technologies or 

treatments. Suppliers often introduce new technologies without adequate evidence of the benefits. The supplier must provide the agency with 

detailed documentation of the product’s benefits 

and performance. 

Convincing the Public 

The introduction of preservation programs also 

affects the traveling public—the ultimate customer—raising a different set of issues and barriers: 

72 

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•	 Understanding the shift from repairing the worst 

pavements first to the best pavements first. The 

public does not understand why agencies would 

be working on good roads but letting the bad 

roads deteriorate. Most of the public understands the importance of maintaining a car or a 

house to prevent major repairs. Pavement preservation engineers should be able to explain the 

value of preventive maintenance treatments now 

compared with the cost of major repairs later. 

•	 Understanding the effects of the various maintenance and rehabilitation strategies on delays and 

vehicle costs. Primary benefits of pavement 

preservation include the potential for reducing 

traffic delays by using faster repair techniques 

and for reducing user costs by maintaining pavement networks in better condition. Although 

widely acclaimed, these benefits still lack the documentation of national studies. 

•	 Understanding safety issues. Increased safety for 

the traveling public and for workers in the work 

zone are other potential benefits from keeping 

roads in good condition through pavement 

preservation treatments; these benefits also need 

to be documented and communicated. 

References 

1.	 Status of the Nation’s Highways, Bridges, and 

Transit: 2002 Conditions and Performance Report. 

Federal Highway Administration, U.S. Department of Transportation, 2003. 

2.	 Asset Management Primer. FHWA-IF-00-010, 

Office of Asset Management, Federal Highway 

Administration, U.S. Department of Transportation, December 1999. 

3.	 Pavement Preservation: A Strategic Plan for the 

Future. FHWA-SA-99-015, Federal Highway 

Administration, U.S. Department of Transportation, 1999. 

4.	 Primer: GASB 34. FHWA-IF-00-010, Office of 

Asset Management, Federal Highway Administration, U.S. Department of Transportation, 

November 2000. 

Galehouse is Director, National Center for Pavement Preservation, 

Michigan State University, Okemos; Moulthrop is Senior Consultant, Fugro-BRE, Austin, Texas; and Hicks is Principal, MACTEC, 

Sacramento, California. 

From TR News, September–October 2003, pp. 4–15. Copyright, 

Transportation Research Board (TRB), National Research Council, 

Washington, D.C. Reprinted with permission of TRB. 

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Preserving Pavements and Budgets 

California’s Strategies Leverage Limited Funds 

by Susan Massey and Pattie Pool 

Pavement preservation is a priority in California, 

which is spending nearly $1 billion in 2003 to keep 

its highway system—the most heavily traveled in the 

nation—in working order. An effective pavement 

preservation program protects the taxpayer investment and improves user perceptions. Pavement 

preservation on the 50,000 lane-miles of California 

highways includes a range of preventive maintenance (PM) techniques applied to pavements in 

good condition. 

PM strategies for flexible pavements include seal 

coats such as chip seals, slurry seals, microsurfacing, 

thin overlays, and crack sealing. PM treatments for 

concrete pavements include crack and joint sealing, 

dowel bar retrofit, partial depth slab repairs, and 

diamond grinding for smoothness and improved 

pavement texture. 

These treatments reduce the amount of water 

infiltrating the pavement, slow the rate of deterioration, or correct surface roughness. Timely application can maintain or extend a pavement’s service life 

another 5 to 10 years before a significant maintenance effort. 

Retiring Distressed Lane-Miles 

When resources are scarce, a policy of funding the 

worst pavement rehabilitation projects first will not 

retire enough distressed lane-miles to maintain a 

healthy state highway system. PM has restored more 

lane-miles at less cost per lane-mile than a rehabilitation-only program would have accomplished. 

The 2003-2004 state fiscal year budget for pavement rehabilitation was nearly $300 million. To 

include some pavement preservation projects in 

that budget, a statewide rating system was used to 

allow projects normally covered in the Capital Preventive Maintenance (CAPM) program to compete 

with the worst roadway rehabilitation projects. 

Through the CAPM program, the California 

Department of Transportation (Caltrans) addresses 

projects in the category between maintenance contracts and full rehabilitation. 

The option that targeted only the worst pavement rehabilitation projects would have retired only 

326 lane-miles of distressed pavement. But the 

option that included the CAPM projects would 

retire more than 1,200 distressed lane-miles with 

the same budget, underscoring the effectiveness of 

pavement preservation. A mixed program of rehabilitation and preservation would include such 

strategies as preventive maintenance contracts, 

CAPM projects, nonconventional asphalt concrete 

treatments, and warranties to help maintain the 

state highway system through the budget crisis. 

Budgeting for PM 

Caltrans set a budget goal of $100 million annually for preventive maintenance: $50 million for 

state-funded maintenance projects and $50 million for federally funded CAPM projects. After several budget reductions in the 2002-2003 state fiscal 

year, Caltrans was able to secure $38 million for 

PM, adding service life to 1,635 lane-miles of pavement. 

In the same state fiscal year, the pavement rehabilitation budget was $340 million, with approximately $30 million from CAPM program funds. 

Approximately 300 lane-miles were rehabilitated at a 

cost of less than $80,000 per lane-mile. In short, PM 

enabled Caltrans to leverage the reduced funds to 

restore more lane-miles than with dedicated funds. 

Typical preventive treatments include modified 

binder (rubberized and polymer-modified), asphalt 

overlays, chip seals, slurry seals, microsurfacing, thin 

bonded wearing course, and recycled materials. 

According to the 2002 Pavement Condition Survey, candidate projects for PM represent approximately 15,000 of the 50,000 total lane-miles in the 

state highway system—that is, about 30 percent of 

the roads are already in good condition. The goal is 

74 

Archived
to treat one-fifth of all PM locations in the first year, 

establishing a 5-year cycle for PM. 

Budget cuts in the 2002-2003 state fiscal year, 

however, allowed allocations for only 60 percent of 

the targeted lane-miles. Nonetheless, earmarking 

part of the budget for PM has made it possible to 

keep up the overall condition of the state highways 

despite the rate of pavement deterioration. 

Caltrans determined that for every $1 spent on 

PM, $3 can be saved on CAPM, $6 on rehabilitation, 

and $20 on reconstruction, if the treatment is 

applied at the right time. Reconstruction in urban 

areas has been more expensive than expected— 

instead of the originally estimated $500,000 per 

lane-mile, costs have exceeded $2 million per lanemile. 

The primary savings for PM comes from a 

reduction in the time spent on design and construction. Before PM, Caltrans performed as much corrective maintenance as the budget allowed, until full 

rehabilitation or reconstruction was necessary. PM 

projects, which involve pavement only, require less 

design time and can be delivered faster. Pavement 

surfaces are renovated with thinner treatments, contributing to faster production. Fewer construction 

working days reduce the disruption to the traveling 

public. 

tractor must meet the performance requirements in 

the specifications. 

In this way, the contractor assumes more responsibility for the materials and workmanship and 

must ensure a high-quality product free from 

defects for one year. Responsibility is placed on the 

contractor, not on the contracting agency. 

When the nonconventional treatments were 

new, the warranty reduced the risk to the state if the 

performance criteria were not met. If there was a 

failure, the contractor had to come back and make 

repairs. A one-year warranty for performance covers such defects as rutting, potholes, raveling, flushing, streaking, and delamination; the financial 

impact on the Caltrans maintenance budget is minimal. 

Although the California state budget is uncertain, the Caltrans Offices of Roadway Rehabilitation 

and Roadway Maintenance will continue to use 

pavement preservation and to dedicate funds to 

cost-effective PM treatments. Caltrans has relied on 

a combination of PM contracts, CAPM projects, 

nonconventional asphalt concrete treatments, and 

warranty projects to make the pavement budget go 

farther. Simple and more cost-effective PM treatments will maintain the highway system at a higher 

level of service, despite a reduced budget for maintenance and rehabilitation. 

Warranties 

The one-year warranty provided another incentive 

for trying nonconventional asphalt concrete products for pavement preservation. The purpose of the 

warranty is to protect the pavement from failure 

during the first year after construction. The conMassey is Supervising Transportation Engineer, Caltrans Office of 

Roadway Rehabilitation; Pool is Transportation Engineering Technician, Caltrans Pavement Management, Sacramento. 

From TR News, September–October 2003, pp. 4–15. Copyright, 

Transportation Research Board (TRB), National Research Council, 

Washington, D.C. Reprinted with permission of TRB. 

75 

Archived
Looking at Long-Term Results 

Performance of Test Section After 13 Years 

by Gary Hildebrand and Scott Dmytrow 

To evaluate the “preventive maintenance effectiveness of flexible pavement treatments,” the Strategic 

Highway Research Program placed sections for Specific Pavement Studies 3 (SPS-3) throughout the 

United States and Canada in the late 1980s and early 

1990s. Each SPS-3 project included test sections that 

received different treatments. The project test sites 

were in four climate zones; exhaustive information 

was recorded at construction; and performance data 

were captured periodically by the Long-Term Pavement Performance team and stored in the DataPave 

software. 

After 13 years, what conclusions can be drawn? 

What is the effectiveness of the preventive maintenance treatments? Following is a report on one SPS3 project in California,1 observed on May 23, 2003. 

History 

A brief history of the California SPS-3 project is as 

follows: 

•	 Circa 1980: Roadway was paved. 

•	 1985: Conventional chip seal was applied. 

•	 1990: SPS-3 maintenance test section was constructed. 

•	 1990 to 2000: No maintenance was performed 

except that crack seal was applied to test and control sections. 

•	 2000: Entire roadway was crack-sealed by a Caltrans maintenance crew. 

Treatments and Conditions 

Different preventive maintenance strategies were 

applied to 11 segments of the test section in 1990. 

One segment was routed and crack sealed, one was 

slurry sealed, five had different chip seals applied, 

and four received different overlays of hot-mix 

asphalt (HMA). The control section received no 

preventive maintenance. 

After 13 years, the segment with rout and crack 

seal was only in marginally better condition than 

the control section. The entire rout-and-crack-seal 

test section had to be crack-sealed during the first 

few years (circa 1992) and again in 2000 to fix adhesion problems. Ride quality on the rout-and-crackseal section is similar to that on the control section. 

In addition, part of this test section has deteriorated 

badly, possibly because of an underlying condition. 

The slurry seal has performed well, with no 

delaminating (i.e., separation from the surface) or 

raveling (i.e., loss of aggregate from the surface)— 

the roadway remains protected. Most of the cracks 

seem to have reflected through the slurry but have 

been crack-sealed, preventing moisture intrusion 

and base damage. 

Overall, the five different chip seals have performed well, with minimal raveling, bleeding (i.e., a 

layer of asphalt binder migrating to the surface), or 

flushing (i.e., minor bleeding of binder). Some chip 

seals, however, had more reflective cracking than 

others. 

The four HMA overlays also have performed 

well, although reflective cracking has occurred in 

the two sections with conventional HMA overlays. 

The fiber and asphalt rubber HMA overlays, however, appear to have an increased resistance to reflective cracking. 

In contrast to the 11 test segments, the control or 

“do nothing” section is in very poor condition. The 

ride quality is bad and the section is in need of more 

than preventive maintenance. The crack filler 

appears to be the only thing keeping this section 

intact. 

Between each test section is an unofficial control 

section. Each of these is also in very poor condition 

and will require more than preventive maintenance. 

76 

Archived
Evaluation 

With the exception of the rout- This site shows that 

a pavement placed 

in 1980 can be 

maintained for more 

than 30 years in a 

condition acceptable 

to the general public 

—and to taxpayers— 

at the cost of a few 

PM treatments.

and-crack-seal section, all of the 

maintenance strategies are performing well. The treatments have 

extended the life of the pavement 

and have kept the roadway in a 

condition acceptable to the 

motoring public. Each of the 

maintained sections could gain 

extended life with the application 

of another maintenance treatment. 

The slurry and seal coat sections require a thin blanket or leveling course to restore ride quality. The thin overlay sections could 

benefit from either a slurry seal or another seal coat, 

because the ride quality generally is good. To obtain 

long-term service from the rout-and-crack-seal or 

control sections, extensive and costly rehabilitation 

strategies may be necessary. 

The treatments applied to this test section 

demonstrate the benefits of PM for roads in good 

condition. When the SPS-3 strategies were applied 

in 1990, the 1985 chip seal was in good shape, the 

ride quality was good, and the distress consisted of 

transverse and longitudinal cracks approximately 

one-quarter inch wide. After 13 years, almost all of 

the PM-treated sections are still serviceable. 

The test site is a very low-volume roadway in a non-freezethaw area. Achieving the same

magnitude of success elsewhere

with any of these strategies, therefore, requires comparable traffic

and weather conditions. 

The test sections prove the viability of PM treatments. Another

PM treatment on the test sections

could extend the life of this roadway another 5 to 10 years. This

site shows that a pavement placed

in 1980 can be maintained for

more than 30 years in a condition

acceptable to the general public—

and to taxpayers—at the cost of a

few PM treatments. 

For more information contact Gary Hildebrand,

Telfer-Windsor Fuel Co., P.O. Box 38, Windsor,

CA 95492 (telephone: 916-354-9760; e-mail:

ghildbrand@telferoil.com). 

1 06A300; GPS Section 061253; Butte County, California; State Route 32;

PM 15.96-18.71; average annual daily traffic: 2,900 vehicles. 

Hildebrand is Pavement Preservation Specialist, Telfer-Windsor 

Fuel Company, Windsor, California; Dmytrow is Technical 

Marketer, Koch Pavement Solutions, Sacramento, California. 

From TR News, September-October 2003, pp. 4-15. Copyright, 

Transportation Research Board (TRB), National Research Council, 

Washington, D.C. Reprinted with permission of TRB. 

77 

Archived
Protecting Roads in the Desert 

Chip Sealing over Fabric Retards Reflective Surface Cracks 

by Lita Davis 

The county of San Diego, California, like many 

other public agencies, is always looking for costeffective ways to maintain roads. Innovation and 

creativity are necessary because the funding often 

does not increase from year to year, although the 

maintenance needs and costs continue to escalate. 

The county of San Diego maintains approximately 

2,000 centerline-miles of public roads in the unincorporated area of San Diego. The county includes 

coastal areas, inland valleys, mountains, and desert 

valleys. 

The county Department of Public Works (DPW) 

follows a preventive maintenance system that 

applies surface treatments to extend the life of structurally sound roadways. The surface treatments in 

the DPW “toolbox” are chip seal, fog seal, slurry 

seal, cape seal, thin lift overlay, and chip seal over 

fabric. 

Chip Seal over Fabric 

In Borrego Springs, the desert 

area of San Diego County, the 

adverse climate and rainfall conditions generate many large surface cracks in the asphalt roadways. Elevations at Borrego 

Springs range from mean sea level 

to 1,830 meters (6,000 feet), with 

ambient temperatures from freezing in the winter to 57 ̊C (135 ̊F) 

in the summer. Rainfall is short in 

duration, but forceful, and is 

associated with flash floods. 

Crack sealing was a common 

maintenance method for desert 

roads, but the cost of addressing 

the large quantities of surface 

cracks did not leave sufficient 

The county 

Department of Public 

Works (DPW) follows 

a preventive 

maintenance system 

that applies surface 

treatments to extend 

the life of structurally 

sound roadways. The 

surface treatments in 

the DPW “toolbox” 

are chip seal, fog 

seal, slurry seal, 

cape seal, thin lift 

overlay, and chip seal 

over fabric. 

funds to apply the final surface treatments to the 

road. In 1987, DPW developed test sections on 

Yaqui Pass Road to evaluate the performance of several surface treatments. The goal was to find a treatment to retard reflective surface cracks under desert 

conditions. 

The following surface treatments were applied 

and evaluated: 

•	 Chip seal with latex emulsion; 

•	 Slow-curing, 2-inch road mix; 

•	 Chip seal with ground rubber and paving asphalt 

binder; 

•	 Chip seal with latex emulsion over pavement 

reinforcing fabric; and 

•	 Chip seal with latex emulsion on recycled asphalt 

surface. 

All of the treatments sealed the 

road surface well, but only chip 

seal over fabric eliminated reflective surface cracks. Moreover, a 

30-year life-cycle cost analysis 

showed that the annual cost was 

one-half that of chip sealing with 

crack sealing. 

Chip sealing over fabric, therefore, has become the standard surface treatment for heavily cracked 

roads in the desert area of San 

Diego County. Material specifications and application procedures 

are as follows. 

Fabric Properties 

The requirements for the pavement-reinforcing fabric follow the 

California Department of Transportation’s standard specifica78 

Archived
tions: fabric manufactured from polyester, polypropylene, or polypropylene-nylon material. The 

fabric is nonwoven and is heat-treated on one side. 

Fabric Placement 

The roads are prepared by cleaning the surface, 

removing pavement markers, and placing protective 

covers on public improvements such as valve cans 

(which provide access to underground utilities), 

survey monument covers, and storm-drain inlets. 

Liquid paving asphalt (AR8000) is the binder for the 

fabric, applied between 290 ̊F and 350 ̊F at a rate of 

0.25 to 0.30 gallon per square yard. 

After placement, the fabric is lightly sanded and 

then seated with pneumatic rollers into the underlying paving asphalt, until the pavement texture is 

replicated on the fabric surface. On low-speed roads 

(35 mph or less), the sanded fabric is exposed to 

traffic for 5 to 10 days before the chip seal is applied. 

On high-speed roads (40 mph or more), the fabric 

and chip seal are placed on the same day. 

Chip Seal Placement 

When the fabric is properly saturated, the chip seal 

is applied at the same rate as on an asphalt surface. 

If the fabric is not saturated, the chip seal emulsion 

must be increased to allow for absorption by the 

fabric and to leave enough emulsion to bind the 

chips. If the fabric is oversaturated, the emulsion 

must be reduced. 

Product Performance 

The 1987 test section on Yaqui Pass Road is still 

functioning. The fabric spans the surface cracks, so 

that crack sealing or crack filling have not been necessary. 

For more information contact Lita Davis, Project Manager and Resident Engineer, County of 

San Diego, Department of Public Works, 5469 

Kearny Villa Road, Suite 201, San Diego, CA 92123 

(telephone: 858-874-4067; e-mail: Lita.Davis@ 

sdcounty.ca.gov). 

The author is Project Manager and Resident Engineer, Department 

of Public Works, County of San Diego, California. 

From TR News, September-October 2003, pp. 4-15. Copyright, 

Transportation Research Board (TRB), National Research Council, 

Washington, D.C. Reprinted with permission of TRB. 

79 

Archived
Research Frontiers in Pavement Preservation 

by Roger M. Larson, Larry Scofield, and James B. Sorenson 

In the past, the major emphasis in the area of pavement was on structural design—project specifications addressed the issues of material quality. Today, 

material properties are being tied directly to structural design and distresses. The surface characteristics that contribute to good functional performance, 

however, often are ignored until problems develop. 

Surface characteristics have gained significance 

with the shift of focus from new construction and 

major rehabilitation to pavement preservation. But 

despite the increasing use of preservation treatments on pavement sections in good structural condition, many state highway agencies still have no 

specifications for the improved functional performance of the pavements. 

Functional performance is determined by how 

well the pavement serves the user. Until now, riding 

comfort—a concept developed in 1957—had been 

the dominant concern. Today the greater need is to 

improve other important functional surface characteristics of pavements. 

Highway User Surveys 

In May 1996, a national survey identified highway 

user concerns. Safety was first, followed by pavement condition, and then traffic flow. Highway 

users wanted an increased focus on the quality of 

roadway surfaces. 

A follow-up infrastructure survey in 2000 found 

that highway users rated improvements to traffic 

flow, safety, and pavement condition as the highest 

priorities. The survey also discovered overall 

increases in dissatisfaction with safety and with 

pavement condition. These are findings that professional engineers can address. 

The results again supported greater consideration of the functional characteristics of pavements. 

In terms of safety, concerns include pavement 

markings, friction in wet weather, and clearing accidents more quickly. Pavements need more durable 

surfaces, a smoother and quieter ride, and better 

surface appearance. 

Longer-Lasting Pavements 

Good highway drainage is fundamental to increase 

surface durability by eliminating or minimizing 

potholes and extending service life. A good cross 

slope is important for surface drainage, improving 

ride quality, improving wet weather friction, and 

reducing splash and spray. Cross-slope deficiencies 

should be corrected as part of any pavement preservation project. 

Because durability affects all other pavement 

characteristics, higher-quality materials and better 

workmanship are necessary for cost-effective construction and preservation. Greater attention to 

materials and workmanship would reduce deterioration and minimize rutting. With current staff 

reductions at many highway agencies, increased use 

of warranties, guarantees, or performance-related 

specifications can help ensure more durable pavement surfaces for highway users. Improved guidelines and incentives for obtaining desirable—not 

minimal—levels of critical surface characteristics 

are necessary. 

Periodic distress surveys are a means of evaluating surface durability—lack of distress indicates 

durability. Established warning levels of texture and 

friction can identify potentially hazardous locations 

before significant numbers of crashes occur. Costeffective corrective actions can be undertaken as 

appropriate. 

Ride Comfort 

Most highway users can relate to ride comfort as a 

criterion for pavements. Several recent publications 

have addressed the research under way to improve 

80 

Archived
guidance for pavement smoothness. Improvements 

are needed in the measurement and evaluation of 

overall smoothness, the detection of bumps, and the 

identification of roughness that would increase 

dynamic loading impacts from trucks. 

Texture, Safety, and Noise 

Pavement texture is often overlooked in project 

specifications. Many state highway agencies have no 

requirements for texture or friction on paved 

asphalt surfaces. 

Specifying friction above minimum levels can 

raise liability concerns. However, considerable evidence shows that higher levels of texture and friction significantly reduce fatalities and injuries—and 

the resulting traffic delays—and can be cost-effective for congested routes and for work zones. 

Improved guidance on the desirable macrotexture 

to reduce splash and spray and hydroplaning and on 

the microtexture to increase friction at low and high 

speeds is needed. National Cooperative Highway 

Research Program Project 1-43, Guide for Pavement 

Friction, is under way to address this concern. 

Safety in work zones—reducing deaths, 

injuries, and traffic delays—also was a concern for 

highway users. In 2002, 1,083 highway workers and 

users were killed in highway work zones. This critical area has few guidelines on texture or friction 

characteristics, particularly in work zone transitions, which involve lane changing, slowing, or 

stopping. The demand for friction, therefore, is 

greater than it is in typical roadway operations. 

Increasing the texture or friction would have a significant effect in reducing the stopping distance, 

which would be expected to reduce crashes in 

highway work zones. 

Safety Plans 

The American Association of State Highway and 

Transportation Officials (AASHTO) has developed 

a comprehensive Strategic Highway Safety Plan to 

reduce highway fatalities by 5,000 to 7,000 annually. 

Eight or more states are piloting an Integrated Safety Management Process to help implement the plan. 

Most of the emphasis in safety-related pavement 

research has been on wet-weather crashes—however, up to 86 percent of all crashes occur on dry roadways. The assumption has been that friction on dry 

roadways was adequate; however, friction has a significant effect on stopping distance, which can be 

expected to reduce crashes from roadway departures and intersections. 

The Federal Highway Administration (FHWA) 

also has set safety goals for the next 10 years, including the following performance measures: 

•	 20 percent reduction in fatalities, 

•	 20 percent reduction in injuries, 

•	 50 percent reduction in truck-related fatalities, 

and 

•	 10 percent reduction in fatalities at intersections 

and in roadway departures by 2007. 

The prevention of all wet-weather crashes would 

not achieve these goals. Therefore, a comprehensive 

program is necessary. Research indicates that up to 

70 percent of wet-weather crashes could be prevented with improved texture and friction. A recent 

study in New York reported that at 40 intersections 

with high crash rates and low friction values, accidents were reduced an average of 61 percent after 

the approaches were given a more skid-resistant 

surface. 

More than 3 million crashes occurred at intersections in 2002, causing nearly 9,000 deaths and 1.5 

million injuries. Since wet-weather crashes represent about 14 percent of all crashes, improved skid 

resistance could result in a 10 percent reduction in 

fatal and serious injuries from crashes and also 

could reduce travel delays. 

Performance Measures 

The effect of increased texture and friction on 

reducing crashes on dry roadways also must be considered, however. None of the AASHTO or FHWA 

goals specifically target the expected overall benefit 

of increased texture and friction on reducing fatalities, injuries, and the resulting traffic delays; pavement skid resistance, however, is among the topics 

under roadway departure. 

Corresponding performance measures are needed—for example, average macrotexture depths that 

can be measured continuously at highway speeds— 

to help monitor whether texture and friction levels 

on the network are increasing as a result of construction or preservation activities. An analysis of 

friction and texture versus average crash rate by 

major roadway classifications would demonstrate 

more clearly the benefit of increased texture and 

friction on reducing fatalities and serious injuries. 

The lack of an accident reduction goal linked to 

increased texture and friction and a corresponding 

81 

Archived
performance measure to monitor progress is a deficiency to be addressed. 

Texture also affects noise. Reduced tire-pavement 

noise levels will benefit highway users, as well as 

adjacent property owners. Specifying desirable 

noise levels has received little emphasis even in 

noise-sensitive projects in urban areas. Therefore, 

completed projects have had large variations in 

noise levels, and the monitoring of noise levels on 

constructed projects has been limited. 

The Arizona Department of Transportation 

(DOT) has one of the most comprehensive studies 

under way to evaluate pavement texture characteristics—both friction and noise—on representative 

surface types in approximately 200 pavement 

preservation test sections. A goal is to develop 

ranges of texture–and the resulting friction and 

noise levels–for a variety of preservation treatments. 

In addition, both Arizona and California DOTs are 

pursuing quieter pavement surfaces to reduce noise 

at the source. 

Surface Appearance 

Specifications for a uniform, pleasing surface 

appearance have received little attention. The 

FHWA Federal Lands Division, however, has made 

this a major issue on the projects it administers for 

the National Park Service. Spot grinding to remove 

bumps can produce differential friction–differences 

in textures changing the skid resistance–and also 

can cause a nonuniform appearance. Surface repairs 

such as partial lane patches also affect both friction 

and appearance. Specifications should not reward 

corrective measures that result in poor appearance 

or that contribute to differential friction, which may 

increase skidding crashes. 

Traffic markings are particularly important for 

visibility at night and in poor weather. Sixty percent 

of roadway departure crashes occur during dark or 

reduced-light conditions. Excluding alcohol-related 

crashes, the nighttime crash rate is about twice the 

daytime rate. Improved durability in traffic markings is required–also important is that the markings 

do not increase the risk of skidding, particularly for 

motorcycles. 

Rumble strips are being used successfully to 

warn drivers that the vehicle is departing from the 

roadway or crossing into an area with a potential for 

a head-on crash. These low-cost treatments have 

been effective in reducing crashes. 

Evaluation Technologies 

Technological advances have facilitated data collection and data analysis. In many cases, results are 

available in real time and presentable in either 

graphical or statistical formats for pavement management, maintenance management, or safety management systems. 

These powerful tools can guide engineering decisions that extend the service life of highways and 

increase highway user satisfaction. Obtaining the 

greatest benefit for the highway agency, however, 

requires increased integration of all management 

systems. 

New high-speed, nondestructive evaluation 

techniques are available or are in development that 

will help differentiate structural and functional 

pavement problems. A rolling-wheel deflectometer 

is in development that will allow continuous highspeed evaluation of the structural strength of 

asphalt pavements by monitoring pavement deflections. The instrument also would help distinguish 

top-down environmental cracking versus bottomup structural fatigue cracking. In Texas and other 

states, ground-penetrating radar is being used to 

locate structural problems in pavements. 

Advances in laser technology allow the measurement of a pavement surface macrotexture at highway speeds. This could minimize the need and 

expense for network-level friction testing. Laser sensors and the newly developed scanning lasers can 

improve evaluation of rutting, aggregate polishing, 

bleeding, surface raveling, and aggregate segregation 

of mixes at relatively low cost. 

These tools can improve decision-making for 

pavement preservation. The techniques will help to 

improve the surface durability and will reduce the 

need for frequent, routine, or reactive pavement 

maintenance. 

Portable devices, such as the circular track (or 

texture) meter and the dynamic friction tester, are 

available to evaluate pavement texture and friction 

values and to develop an international friction 

index. These stationary devices require lane closures 

for testing but allow a relatively quick comparison 

of surfaces. Arizona DOT, the National Center for 

Asphalt Technology, and others are using the equipment in studies. 

82 

Archived
Performance and Ride 

The FHWA Office of Asset Management has initiated a project that uses pavement management systems to evaluate the performance of Superpave 

mixes. Many states have adopted the Superpave system and need to verify that the forecast 

benefits–including improved safety, durability, and 

longer service lives–are being achieved. 

These evaluations should substantiate improvements to safety and to surface durability–two of the 

major concerns of highway users. FHWA’s emphasis 

on pavement preservation also should lead to 

improved surface durability and should minimize 

the amount of routine or reactive maintenance of 

pavement surfaces. 

The FHWA Pavement Smoothness Initiative has 

made significant changes in evaluating ride comfort–for example, adopting the International 

Roughness Index (IRI) as the standard measurement unit and using the lightweight laser profiler to 

monitor construction quality and to provide an initial value for monitoring long-term performance. A 

new effort is under way to develop bump specifications, including grinds or repairs, and to ensure that 

roughness does not cause dynamic loading by 

trucks that would increase the rate of structural 

damage to the pavement. 

The FAA guidelines for airport runways are a 

best-practice example that could be modified to 

address various highway pavement classes. The FAA 

guidelines address friction and texture for new construction and for maintenance activities, including 

desirable friction and texture for new surfaces, 

maintenance threshold levels, and minimum 

acceptable levels. 

Texture affects both noise and friction and 

should not be considered independently. Texture 

and friction should be addressed specifically to 

reduce the current, unacceptable levels of 43,000 

fatalities and 2.9 million injuries annually in highway crashes and to minimize the resulting traffic 

delays. 

Refining the Tools 

Technological advances are providing the tools to 

assist practitioners in developing more cost-effective pavement preservation strategies. The new 

technologies should enable researchers to develop 

cost-effective pavement guidelines that contribute 

to reducing fatalities and serious injuries and that 

also reduce noise impacts for highway users and 

adjoining property owners. Additional research 

must refine these tools further and introduce the 

advances into widespread use. 

Addressing Texture 

Few specifications address texture or friction. Texture is important to the friction and noise properties of the pavement surface. The few states that 

have guidelines typically address the minimum, not 

the desirable, values. No state has requirements that 

address the maximum or desirable noise levels for 

the various surface types. 

Larson is Senior Engineer, Applied Pavement Technology, Inc., 

Springfield, Virginia; Scofield is Research Engineer, Arizona Department of Transportation, Phoenix; and Sorenson is Construction and 

System Preservation Team Leader, Federal Highway Administration, 

Washington, D.C. 

From TR News, September–October 2003, pp. 22-25. Copyright, 

Transportation Research Board (TRB), National Research Council, 

Washington, D.C. Reprinted with permission of TRB. 

83 

Archived
Investing in the Future of Roads 

by Jim Sorenson 

The goal of “Keeping good roads good” is behind a 

growing number of pavement preservation programs nationwide. Information on what states, 

industry and others have accomplished can now be 

found on a new CD available from the Federal 

Highway Administration (FHWA), National Pavement Preservation Forum II: Investing in the Future 

(Publication No. FHWA-IF-03-019). 

The CD contains presentations and papers from 

the National Pavement Preservation Forum II, 

which was held in San Diego, Calif., in November 

2001. The conference gave participants an opportunity to share success stories, detail challenges and 

discuss the future of pavement preservation. The 

event, which was a follow-up to the 1998 Forum for 

the Future, was sponsored by the Foundation for 

Pavement Preservation, FHWA and the California 

Department of Transportation (Caltrans). 

"Keeping good roads good" involves the timely 

application of carefully selected treatments to maintain or extend a pavement’s service life. These treatments may include various types of surface seals, 

thin lift overlays and crack sealing for asphalt pavements. Treatments for concrete pavements might 

include crack and joint sealing, diamond grinding 

and retrofit dowel bars. The key is to apply the treatments when the pavement is still in good condition, 

with no structural damage. Placing a treatment too 

late will result in poor performance, while applying 

treatments too early can cause other pavement 

problems and use up funds before they are needed. 

Applying the right treatment to the right road at the 

right time allows highway agencies to get the most 

out of their maintenance dollars. 

Conference participants stressed the importance 

of education and awareness as vehicles for promoting pavement preservation. Other keys to success 

cited by forum participants were: 

•	 Adequate dedicated funds; 

•	 Effective marketing of preventive maintenance; 

•	 Support from management; 

•	 Legislative support; 

•	 Training and buy-in of workers; and 

•	 Public awareness of the financial benefits of 

preventive maintenance. 

Conference co-sponsor Caltrans began its pavement preservation efforts in 1992 and now issues an 

annual Pavement Condition Report, which it uses to 

determine high-priority needs. The agency also 

developed 10-year pavement goals, which were 

implemented in 1998. These goals include reducing 

the backlog of distressed lane miles from 14,000 to 

5,000 by 2008. Preventive maintenance work completed to date has included applying a 1.2-in. 

asphalt rubber overlay to 150 lane miles of I-5 in 

Fresno. The work, which was performed by the 

Granite Co., had to be completed in 65 days and 

come with a one-year warranty. The overlay 

"improved the ride dramatically and extended the 

pavement life by 10 additional years," said conference co-chair Larry Orcutt of Caltrans. 

Forum participants noted that training is fundamental to spreading the word about pavement 

preservation. 

In response to state and industry needs, FHWA 

has developed a series of pavement preservation 

training courses. Two courses are currently being 

offered to highway agencies through FHWA’s 

National Highway Institute (NHI), while two more 

are expected to be available by fall 2003. Pavement 

Preservation: The Preventive Maintenance Concept 

is targeted toward highway agency decision makers, 

management, senior maintenance staff and others 

who have the ability to create and fund department 

programs and initiatives. Selecting Pavements for 

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Preventive Maintenance targets engineers and field 

supervisors who make decisions about which roads 

receive treatment and when. Still under development are courses on Design and Construction of 

Quality Preventive Maintenance Treatments and 

Pavement Preservation: Integrating Pavement 

Preservation Practices and Pavement Management. 

Also important to the success of pavement 

preservation programs is documenting the benefits 

of preventive maintenance. As forum participants 

noted, data must be accurate and it also should be 

accesssible. 

To obtain a copy of the Forum II CD, contact 

Steve Mueller at FHWA, 202/366-1557; fax: 202/ 

366-9981; e-mail: steve.mueller@fhwa.dot.gov.* 

Pavement preservation treatments for asphalt 

pavements can include slurry seals, which are 

shown here. 

Sorenson is a senior highway engineer in FHWA’s Office of 

Asset Management. He can be reached at 202/366-1333; 

fax: 202/366-9981; e-mail: james.sorenson@fhwa.dot.gov. 

Reprinted from Roads & Bridges, August 2003. 

*The FHWA contact for copies of resources or current information 

on this topic is Joe Gregory, 202-366-1557 (email: joseph. 

gregory@dot.gov). 

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When Prevention Is the Cure 

by Tom Kuennen 

A current pavement inventory, identification of 

conditions, and correct timing of pavement preservation applications are the secrets to successful 

preservation of hot-mix asphalt driving surfaces, 

according to a growing body of experts and 

research. 

Naturally, government agencies want to keep citizens happy by providing as large an inventory of 

smooth streets as possible. But state, city, and county road agencies alike have to remember that maintenance techniques applied to pavements that are 

completely deteriorated beyond a certain point are a 

waste of money. 

A “worst-first” pavement maintenance philosophy tosses scarce public funding at pavements that 

should be allowed to fail first, then be reconstructed 

in an orderly, programmatic manner. 

Asphalt pavements will perform well and deteriorate very slowly through the first eight to 10 years 

of their lives, then fail rapidly as an assortment of 

ills does them in. 

The best way, experts say, to spend scarce maintenance funds is to determine where the pavement is 

in its life-cycle “curve,” and apply preventive maintenance techniques just before the period of rapid 

deterioration sets in. 

Unfortunately, the public agencies responsible 

for pavements ultimately must answer to elected 

officials. It takes guts for a public works supervisor 

to insist to a mayor or aldermen that the municipality will get the best use of funds by allowing a street 

to fall apart before rebuilding, despite what the voters say. 

Support for preservation 

Experts agree pavement preservation is best executed in the framework of a pavement management 

system that will enable a road agency to identify 

pavement condition throughout its road inventory. 

Not only will such a system help allocate where 

funds are best spent, but it will also provide a database to prove the long-term benefits of pavement 

preservation and justify additional preservation 

spending. 

“The key is to have a good pavement management system that will allow you to track the condition of your pavements over time,” says Mark 

Buncher, Ph.D., P.E., director of field engineering 

for The Asphalt Institute. “The best preventive 

maintenance practice will be indicated by the pavement history in a pavement management system.” 

Today, programmed pavement preservation is 

gaining major support from some heavy hitters in 

the road and bridge community. 

•	 The Federal Highway Administration delivers 

pavement preservation guidance and moral support through its Office of Asset Management. 

•	 The Foundation for Pavement Preservation, a 

public/private venture, is funding and managing 

research into pavement preservation materials, 

techniques, training, and best practices—and 

publicizing best practices via outreach to governments and contractors. (visit at http://fp2.org). 

•	 The American Association of State Highway & 

Transportation Officials recently launched a 

web site devoted to agency asset management 

and pavement preservation (visit at http:// 

assetmanagement.transportation.org/ ). 

•	 The pending GASB 34 accounting regulations 

now being adopted from coast to coast are compelling municipal and county governments to 

reconsider their philosophy toward the transportation infrastructure they possess, counting it 

as an asset that must be nurtured and maintained, rather than just a network of streets and 

highways that wears out and must be fixed. 

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A new way of thinking makers—to be cognizant of the investments we’re 

The theme of asset management supporting pavement preservation is driving the new emphasis on 

preventive maintenance for the local and state 

transportation infrastructures of the 21st century. 

“Pavement preservation is at the core of all 

future highway programs,” says Bill Ballou, president of the Foundation for Pavement Preservation. 

“Without asset and system management, we can’t 

maintain highway systems cost-effectively. We want 

pavement preservation to be a routine undertaking 

for road agencies.” 

“Pavement preservation is more than just a collective set of specific pavement maintenance techniques,” said FHWA’s Office of Asset Management 

Construction and System Preservation Team leader 

Jim Sorenson at last year’s annual meeting of the 

International Slurry Surfacing Association. “It is a 

way of thinking and the guiding force behind an 

agency’s financial planning and proper asset management.” 

And that leads to challenges in asphalt pavement 

preservation and maintenance, Sorenson said at an 

FP2 conference in 2000. “The vast majority (about 

94%) of U.S. pavements are made of asphalt,” he 

said. “The balance of the pavements in the highservice corridors are of portland cement concrete. 

We make choices, and we need the competition 

between the industries. But the mainstay of our 

pavements is black, and that’s where we need to 

place much of our preservation focus.” 

Sorenson adheres to the classic definition of 

pavement preservation—application of the right 

treatment, to the right road, at the right time. “We 

have to get the best bang for the buck out of those 

asphalt pavements,” Sorenson said. “That means we 

have to do at least something at the right time.” And 

to be able to respond at the right time requires planning and budgeting, he said. 

Asset management 

Since 2000, the FHWA has promoted transportation 

infrastructure asset management as a best practice 

for state and local road and bridge owners. Asset 

management is a philosophy borrowed from the 

private sector, now being applied to government 

agency-owned transportation infrastructure. 

“Asset management is a business process that’s 

being introduced into the highway community to 

allow agency top management—our policy decision 

making in our highway system,” Sorenson says. 

“Highways are a big business, and every dollar 

that we invest in the highway system must get a high 

rate of return. And in the United States, in the postwar era, we can show those returns in the way our 

economy has stabilized and developed.” 

For more information and tools to use, visit the 

FHWA’s Office of Asset Management at www.fhwa. 

dot.gov/infrastructure/asstmgmt/index.htm. 

Foundation for preservation 

Research and educational support of long-lived 

pavements through preventive maintenance is being 

undertaken by the public/private-funded Foundation for Pavement Preservation. 

Commonly known as FP2 (“FP squared”), the 

foundation is the nation’s leading proponent of 

pavement preservation. Like FHWA’s Sorenson, the 

foundation believes that proper pavement preservation means application of the right treatment, to the 

right road, at the right time, and communicates this 

principle to the top management levels of government agencies, as well as to field personnel. 

FP2 funds and conducts research, coordinates 

development of educational courses and programs, 

sponsors symposia and workshops, issues external 

publications, and identifies research problem statements for future work. 

Established in 1992, FP2 is facilitating change in 

the transportation infrastructure community, 

Sorenson says, by providing resources to advance 

knowledge for improved asset management for 

maintaining and preserving highway pavements. 

“We are closely monitoring how reauthorization 

will support pavement preservation,” says FP2’s 

Ballou. “While we are not a lobbying group, we are 

acutely aware of the need to include pavement 

preservation research funding, as well as system 

preservation funding itself.” 

In 2001, FP2 began high-level talks with the 

FHWA and the American Association of State Highway & Transportation Officials to readdress pavement preservation research and policy needs, and to 

establish a focus for a national program. And last 

February, FP2 brought FHWA, AASHTO, and private sector stakeholders together into a “Strategic 

Partnership in Pavement Preservation Research” 

initiative to identify common ground as TEA-3 

approaches. “We discussed reauthorization and how 

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we could participate and what our best options 

were,” Ballou says. 

Sealer/binder research 

Ongoing research on surface sealants and rejuvenators being coordinated by FP2 likely will pay big dividends in the near and long term. 

Sealers have been used in approximately twothirds of the states, the foundation reports. Rejuvenators are formulated to penetrate into the pavement and enhance the properties of the asphalt 

binder of the existing pavement. 

To explore which treatments will work best 

under which climatic conditions, the FHWA contracted with FP2 in February 2001 to evaluate the 

effectiveness of spray-applied emulsified sealer/ 

binders and rejuvenators. 

This was a unique approach as it brought together a partnership between industry and the FHWA. 

Although the FHWA provides the significant share 

of research funding, the pavement preservation 

industry also contributes to this effort through the 

foundation. FP2 conducts the research through its 

partners and contractors. 

As part of this research, a workshop and field 

application of test sections was conducted in early 

autumn 2002 in southern Minnesota. 

Preservation through maintenance 

Preventive maintenance is a means to achieving 

pavement preservation. 

“Preventive maintenance applies lower-cost 

treatments to retard a highway’s deterioration, 

maintain or improve the functional condition, and 

extend the pavement’s service life,” says retired 

Michigan DOT pavement preservation engineer 

Larry Galehouse, P.E., L.S. 

“With various short-term treatments, preventive 

maintenance can extend pavement life an average of 

5 to 10 years,” Galehouse says. “Applied to the right 

road, at the right time—when the pavements are 

mostly in good condition—preventive maintenance 

can improve the network condition significantly at 

a lower unit cost.” 

Beginning in 1992, Galehouse’s work at the 

Michigan DOT provided hard evidence that preventive maintenance is a wise investment. According 

to a study undertaken by the DOT and confirmed 

by an independent consultant, in the long run 

Michigan’s preventive maintenance strategy is more 

than six times as cost-effective as rehabilitation and 

reconstruction projects in providing acceptable 

driving surfaces. 

In Michigan, surface treatments for flexible pavement surfaces include microsurfacing, chip seals, 

slurry seals, crack sealing, 0.75-inch overlays of 

ultrathin hot-mix asphalt, and 1.5-inch hot-mix 

asphalt overlays, Galehouse says. 

Ills of asphalt pavements 

Such procedures mitigate the degenerative problems 

that hot-mix asphalt pavements endure. Some 

asphalt pavement ills—like raveling—indicate the 

need for immediate pavement preventive maintenance. Others, like alligator cracking, indicate a pavement that has deteriorated too far, or a subbase that 

requires repair lest good money be thrown after bad. 

•	 Raveling is the separation of the surface aggregate from the asphalt binder. As aggregate moves 

out of the mix, the surface becomes rougher in 

texture. Aggregate that has “raveled” out of the 

matrix can be found in gutters and close to drain 

inlets. The cause usually is oxidation by sun and 

weather, as the asphalt binder is broken down by 

the elements. This can begin early in a pavement’s life. Surface treatments are indicated. 

•	 Bleeding, also known as flushing, is the exuding 

of binder onto pavement surface; it’s caused by 

excessive amounts of liquid asphalt binder in 

mix or low air void content (densification) 

caused by excessive traffic, and appears during 

hot weather. A seal coat can help, or overlay of an 

open-graded friction course. 

•	 Rutting is longitudinal deformation of pavement; it’s caused by high levels of repeated stress 

being applied to the subgrade below the asphalt 

course, or by an asphalt mix without enough 

shear strength to resist repeated heavy loads. 

Some say rutting can’t be fixed by preventive 

maintenance treatments other than cold mill and 

overlay, or hot in-place surface recycling; others 

say an asphalt thin surfacing or microsurfacing 

will satisfactorily fill ruts while leaving a new 

driving surface. 

•	 Corrugation or “washboarding” is a transverse 

deformation of pavement, and can be caused by 

poor compaction technique or a shifting of the 

subgrade. It can’t be fixed by preventive maintenance methods. 

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•	 Fatigue, or alligator cracking, is interconnected 

cracking with a pattern resembling the hide of an 

alligator. Its primary cause is attributed to base 

failure, or heavy traffic loading combined with 

partial base failure, so it can’t be cured with a 

preventive maintenance treatment. However, 

mild cases of alligatoring with minimal base 

involvement can be treated with seal surfacing. 

New look at fatigue cracking 

This spring a contract was pending for new research 

into fatigue cracking, as proposed by the National 

Cooperative Highway Research Program. Project 1­

42, Top-Down Fatigue Cracking of Hot-Mix 

Asphalt Layers, would be a two-year, $400,000 project that will take another look at why fatigue cracking happens. 

Until recently, load-associated fatigue cracking of 

hot-mix asphalt pavements that occur in the wheel 

path have been thought to always initiate at the bottom of the HMA layer and propagate to the surface, 

NCHRP says. 

But new studies indicate that load-related fatigue 

cracks can also be initiated at the surface of the 

pavement and propagate downward through the 

HMA layer, NCHRP says. These studies say environmental conditions, tire-to-pavement interaction, mixture characteristics, pavement structure, 

and construction practices are among the factors 

that influence the occurrence of this cracking. 

Research proposed by NCHRP would identify 

mechanisms that govern the initiation and propagation of top-down fatigue cracking, identify or develop methods of lab-testing HMA mixes for susceptibility to surface cracking, determine factors associated with top-down fatigue cracking, and identify 

predictive models. 

Preservation techniques 

A variety of techniques and materials can be used to 

preserve a pavement—if it is at the right stage in its 

life. These include chip seals, fog seals, cape seals, 

slurry seals, microsurfacing, and thin-lift hot-mix 

asphalt overlays. But before spending money on an 

application, the engineer must determine if the 

treatment will actually prolong pavement life. 

“There are lots of different tools in the tool box 

to choose from,” the Asphalt Institute’s Buncher 

says. “The pavement owner will have to choose the 

best solution for the funds that are available.” 

For example, most fatigue or alligator cracking 

indicates a failed subgrade following years of weathering and traffic loads. The existing fatigued asphalt 

and base must be milled or dug out, then rebuilt 

prior to placement of a treatment or new lift of 

asphalt. 

Rutted asphalt may be treated by a thin-lift HMA 

overlay, or by microsurfacing. But a chip seal or 

slurry seal will do little to improve the riding surface, much less prolong pavement life. 

Simple raveling, on the other hand, may be treated by a number of surfacing solutions, including the 

family of surface seals. 

“The application of slurry seal will significantly 

extend the life of existing pavements by protecting 

the under-surface from damage caused by water 

seepage,” says the International Slurry Surfacing 

Association. “Improved surface performance is an 

added bonus. A pavement maintenance program 

using slurry seal will not only help to protect your 

pavement, it will help to protect your paving investment.” 

Simple pavement seals 

There are four approaches to pavement sealing in 

common use today. 

The classic chip seal is an inexpensive solution 

for an oxidized or raveling asphalt pavement. An 

asphalt chip seal, also referred to as a seal coat or a 

bituminous surface treatment, consists of sequential 

applications of asphalt and stone chips, applied 

either singly or in layers, to build up a structure that 

can approach 1-inch thick, according to the National Highway Institute’s course of instruction, Techniques for Pavement Rehabilitation. 

Rubberized asphalt chip seals are a special type of 

chip seal in which rubber (ground-rubber tires) is 

blended with the asphalt cement. “This application 

has been used both as a SAM (stress-absorbing 

membrane) and a SAMI (stress-absorbing membrane interlayer) to help reduce reflection cracking, 

but it has also been used without overlays,” NHI 

says. 

Fog seals are very light applications of an emulsion to the pavement surface with no aggregate, 

according to NHI. “These applications seal the surface and provide a small amount of rejuvenation, 

depending on the type of emulsion used and the 

condition of the existing pavement surface,” NHI 

says. 

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Cape seals are a combination of chip seal and 

slurry surfacing or seal. “For paved roads, the chip 

seal is applied first and, between four and 10 days 

later, the slurry seal is applied,” NHI says. For unsurfaced roads, an application of penetration oil (MC70 or SC-70) is applied first as a prime coat, followed about two days later by a chip seal and about 

two weeks later by a slurry seal. 

Slurry surfacings 

A slurry surfacing, also known as a slurry seal, is a 

mixture of aggregates dispersed in asphalt and 

applied in a slurry state. 

“Slurry seal is a mixture of an asphaltic oil and 

water (emulsion) and crushed rock aggregate that is 

spread over the street at about one-fourth-inch 

thickness,” says the City of Austin (Texas) Street and 

Bridge Division. “The slurry ‘cures’ when the water 

evaporates, leaving only the asphalt to coat the 

crushed rock.” 

Afterward, the asphalt acts as a binder to hold the 

slurry together and bond to the existing pavement. 

The slurry seal protects the existing street surface 

from the effects of aging and oxidizing and increases the skid resistance. 

“Slurry seals typically include some crack sealing 

on cracks 0.1875-inch and larger,” Austin says. “Prep 

work may also include a minor amount of level-up 

and surface replacement areas depending upon conditions; however, slurry seal is typically used on 

streets that are in good to excellent condition.” 

“Slurry surfacings are designed in a lab, are proportioned by the slurry machine, and laid down and 

cured so the asphalt-to-aggregate ratio is maintained at the optimum value to assure uniform 

aggregate coating and adhesion,” says Jeff Reed, 

president, Valley Slurry Seal Co., Sacramento. 

Such surfaces use very large fractions of fines 

material, giving a very high surface area and a lot of 

microstructure, leading to a sandpaper surface and 

a high skid resistance, while maintaining a smooth 

finish, Reed says. 

Microsurfacing evolved from slurry 

Microsurfacing is a more advanced extension of 

the slurry-surfacing concept. Microsurfacing is 

described as a polymer-modified, cold-mix paving 

system that can remedy a broad range of problems 

on today’s streets, highways, and airfields. 

Like slurry seal, microsurfacing begins as a mixture of dense-graded aggregate, asphalt emulsion, 

water, and mineral fillers, says the International 

Slurry Seal Association, but microsurfacing has 

added capabilities, thanks to the use of advanced 

polymers and other modern additives. 

Introduced in the United States in 1980, microsurfacing is made and applied to existing pavements 

by a specialized machine which carries all components, mixes them on-site, and spreads the mixture 

onto the road surface. These materials are continuously and accurately measured, and then thoroughly combined in the microsurfacer’s mixer. 

As the machine moves forward, the mixture is 

continuously fed into a full-width “surfacing” box, 

which spreads the width of a traffic lane in a single 

pass, the ISSA says. Also, specially engineered “rut” 

boxes—designed to deliver the largest aggregate 

particles into the deepest part of the rut to give 

maximum stability in the wheel path—may be used 

to fill ruts. Edges of the microsurface mat are automatically feathered. 

Thin surfacings 

The next step up from microsurfacing is a fullblown hot-mix asphalt thin surfacing. This consists 

of a single layer of hot-mix asphalt (minimum of 1­

inch thick, but often 2-inches thick) used to level, 

waterproof, and restore the original street shape and 

ride. 

Thin overlays for pavement maintenance got a 

big boost this year when the results of a National 

Cooperative Highway Research Project were 

revealed at the 82nd meeting of the Transportation 

Research Board in Washington in January. 

There, a paper on NCHRP Project 20-50 

(03/04)—LTPP Data Analysis: Effectiveness of Maintenance and Rehabilitation Options—assessed the 

relative performance of different pavement maintenance and rehab treatments, including the influence 

of pretreatment condition and other factors on 

treatment effectiveness. 

The study was executed by Kathleen T. Hall and 

Carlos E. Correa, both with ProTech Engineering, 

Inc., and Amy L. Simpson, now with PCS-Law. Data 

used in the study were drawn from the Long-Term 

Pavement Performance Studies SPS-3 experiment. 

“In terms of roughness, rutting, and fatigue 

cracking, the most effective of the maintenance 

treatments in the SPS-3 core experiment has been 

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the thin overlay treatment, followed by the chip seal treatment, 

and then the slurry seal treatment,” they write. “The thin overlay treatment was the only one of 

the four SPS-3 maintenance treatments to produce an initial (albeit 

small) reduction in roughness, 

and the only one of the four to 

have a significant effect on longterm roughness, relative to the 

control sections.” 

For rougher pavements, however, there was some evidence that 

chip seals and slurry seals also had 

some effect on long-term roughness, rutting, and cracking, rela­

“Preventive 


maintenance applies
 

lower-cost treatments
 

to retard a highway’s
 

deterioration, maintain
 

or improve the 


functional condition,
 

and extend the 


pavement’s 


service life.”
 

effect on initial and long-term 

condition levels, and is not meant 

to imply anything with regard to 

the relative cost-effectiveness of 

the different treatments. “The 

most effective treatment is not 

always the most cost-effective 

treatment,” the authors warn. 

Options are vast 

The options available to pavement 

engineers to help preserve pavements are vast, sophisticated, and 

are getting better. But perhaps the 

engineers’ biggest challenge will 

be to move forward and apply 

tive to the control sections. “Slurry seals and crack 

seals did not have any significant effect on longterm roughness, rutting, or fatigue cracking,” the 

authors reported. 

It should be kept in mind that the term effectiveness, as used in this paper, refers to the magnitude of 

true pavement preservation principles to the infrastructure under their control. Fortunately, support 

is building for pavement preservation, and they 

won’t be alone. 

Reprinted from Better Roads, June 2003. Better Roads can be visited online at www.BetterRoads.com. 

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Memorandum 

Subject: ACTION: Pavement Preservation Definitions 

Date: September 12, 2005 

From: David R. Geiger, P.E. 

Director, Office of Asset Management 

Reply to Attn. of: HIAM-20 

To: Associate Administrators 

Directors of Field Services 

Resource Center Director and Operations Manager 

Division Administrators 

Federal Lands Highway Division Engineers 

As a follow-up to our Preventive Maintenance memorandum of October 8, 2004, it has come to our 

attention that there are differences about how pavement preservation terminology is being interpreted 

among local and State transportation agencies (STAs). This can cause inconsistency relating to how the 

preservation programs are applied and their effectiveness measured. Based on those questions and a 

review of literature, we are issuing this guidance to provide clarification to pavement preservation definitions. 

Pavement preservation represents a proactive approach in maintaining our existing highways. It enables 

STAs to reduce costly, time consuming rehabilitation and reconstruction projects and the associated 

traffic disruptions. With timely preservation we can provide the traveling public with improved safety 

and mobility, reduced congestion, and smoother, longer lasting pavements. This is the true goal of pavement preservation, a goal in which the FHWA, through its partnership with States, local agencies, industry organizations, and other interested stakeholders, is committed to achieve. 

A Pavement Preservation program consists primarily of three components: preventive maintenance, 

minor rehabilitation (non structural), and some routine maintenance activities as seen in figure 1. 

Routine 

Maintenance 

Minor 

Rehabilitation 

Preventive 

Maintenance 

Pavement 

Preservation 

Figure 1. Components of pavement preservation. 

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An effective pavement preservation program can benefit STAs by preserving investment on the NHS 

and other Federal-aid roadways, enhancing pavement performance, ensuring cost-effectiveness, 

extending pavement life, reducing user delays, and providing improved safety and mobility. 

It is FHWA’s goal to support the development and conduct of effective pavement preservation programs. As indicated above, pavement preservation is a combination of different strategies which, 

when taken together, achieve a single goal. It is useful to clarify the distinctions between the various 

types of maintenance activities, especially in the sense of why they would or would not be considered preservation. 

For a treatment to be considered pavement preservation, one must consider its intended purpose. 

As shown in Table 1 below, the distinctive characteristics of pavement preservation activities are that 

they restore the function of the existing system and extend its service life, not increase its capacity 

or strength. 

Definitions for Pavement Maintenance Terminology 

Pavement Preservation is “a program employing a network level, long-term strategy that enhances 

pavement performance by using an integrated, cost-effective set of practices that extend pavement 

life, improve safety and meet motorist expectations.” 

Source: FHWA Pavement Preservation Expert Task Group 

An effective pavement preservation program will address pavements while they are still in good condition and before the onset of serious damage. By applying a cost-effective treatment at the right 

time, the pavement is restored almost to its original condition. The cumulative effect of systematic, 

successive preservation treatments is to postpone costly rehabilitation and reconstruction. During 

the life of a pavement, the cumulative discount value of the series of pavement preservation treatments is substantially less than the discounted value of the more extensive, higher cost of reconstruction and generally more economical than the cost of major rehabilitation. Additionally, perTable 1. Pavement preservation guidelines. 

Increase Increase Reduce Restore 

Type of Activity Capacity Strength Aging Serviceability 

New Construction X X X X 

Reconstruction X X X X 

Major (Heavy) 

Rehabilitation X X X 

Structural Overlay X X X 

Pavement 

Minor (Light) Rehabilitation X X 

Preventive Maintenance X X 

Preservation 

Routine Maintenance X 

Corrective (Reactive) Maintenance X 

Catastrophic Maintenance X 

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forming a series of successive pavement preservation treatments during the life of a pavement is less 

disruptive to uniform traffic flow than the long closures normally associated with reconstruction 

projects. 

Preventive Maintenance is “a planned strategy of cost-effective treatments to an existing roadway 

system and its appurtenances that preserves the system, retards future deterioration, and maintains 

or improves the functional condition of the system (without significantly increasing the structural 

capacity).” 

Source: AASHTO Standing Committee on Highways, 1997 

Preventive maintenance is typically applied to pavements in good condition having significant 

remaining service life. As a major component of pavement preservation, preventive maintenance is 

a strategy of extending the service life by applying cost-effective treatments to the surface or nearsurface of structurally sound pavements. Examples of preventive treatments include asphalt crack 

sealing, chip sealing, slurry or micro-surfacing, thin and ultra-thin hot-mix asphalt overlay, concrete 

joint sealing, diamond grinding, dowel-bar retrofit, and isolated, partial and/or full-depth concrete 

repairs to restore functionality of the slab; e.g., edge spalls, or corner breaks. 

Pavement Rehabilitation consists of “structural enhancements that extend the service life of an 

existing pavement and/or improve its load carrying capacity. Rehabilitation techniques include 

restoration treatments and structural overlays.” 

Source: AASHTO Highway Subcommittee on Maintenance 

Rehabilitation projects extend the life of existing pavement structures either by restoring existing 

structural capacity through the elimination of age-related, environmental cracking of embrittled 

pavement surface or by increasing pavement thickness to strengthen existing pavement sections to 

accommodate existing or projected traffic loading conditions. Two sub-categories result from these 

distinctions, which are directly related to the restoration or increase of structural capacity. 

Minor rehabilitation consists of non-structural enhancements made to the existing pavement 

sections to eliminate age-related, top-down surface cracking that develop in flexible pavements due to environmental exposure. Because of the non-structural nature of minor rehabilitation techniques, these types of rehabilitation techniques are placed in the category of 

pavement preservation. 

Major rehabilitation “consists of structural enhancements that both extend the service life of 

an existing pavement and/or improve its load-carrying capability.” 

Source: AASHTO Highway Subcommittee on Maintenance Definition 

Routine Maintenance “consists of work that is planned and performed on a routine basis to maintain and preserve the condition of the highway system or to respond to specific conditions and 

events that restore the highway system to an adequate level of service.” 

Source: AASHTO Highway Subcommittee on Maintenance 

Routine maintenance consists of day-to-day activities that are scheduled by maintenance personnel 

to maintain and preserve the condition of the highway system at a satisfactory level of service. 

Examples of pavement-related routine maintenance activities include cleaning of roadside ditches 

and structures, maintenance of pavement markings and crack filling, pothole patching and isolated 

overlays. Crack filling is another routine maintenance activity which consists of placing a generally, 

bituminous material into “non-working” cracks to substantially reduce water infiltration and rein94 

Archived
force adjacent top-down cracks. Depending on the timing of application, the nature of the distress, 

and the type of activity, certain routine maintenance activities may be classified as preservation. 

Routine Maintenance activities are often “in-house” or agency-performed and are not normally eligible for Federal-aid funding. 

Other activities in pavement repair are an important aspect of a STA’s construction and maintenance program, although they are outside the realm of pavement preservation: 

Corrective Maintenance activities are performed in response to the development of a deficiency or deficiencies that negatively impact the safe, efficient operations of the facility and future 

integrity of the pavement section. Corrective maintenance activities are generally reactive, not 

proactive, and performed to restore a pavement to an acceptable level of service due to unforeseen conditions. Activities such as pothole repair, patching of localized pavement deterioration, e.g. edge failures and/or grade separations along the shoulders, are considered examples 

of corrective maintenance of flexible pavements. Examples for rigid pavements might consist 

of joint replacement or full width and depth slab replacement at isolated locations. 

Catastrophic Maintenance describes work activities generally necessary to return a roadway 

facility back to a minimum level of service while a permanent restoration is being designed 

and scheduled. Examples of situations requiring catastrophic pavement maintenance activities include concrete pavement blow-ups, road washouts, avalanches, or rockslides. 

Pavement Reconstruction is the replacement of the entire existing pavement structure by the 

placement of the equivalent or increased pavement structure. Reconstruction usually requires 

the complete removal and replacement of the existing pavement structure. Reconstruction 

may utilize either new or recycled materials incorporated into the materials used for the 

reconstruction of the complete pavement section. Reconstruction is required when a pavement has either failed or has become functionally obsolete. 

If you need technical support or further guidance in the pavement preservation area, please contact 

Christopher Newman in the FHWA Office of Asset Management at (202) 366-2023 or via e-mail at 

Christopher.Newman@fhwa.dot.gov. 

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Resources
 

To learn more about pavement preservation, visit FHWA’s Transportation System 

Preservation Web site at www.fhwa.dot.gov/preservation. Resources on the site include 

fact sheets, a checklist series with details on pavement preservation applications and 

techniques, and information on research studies. 

Information is also available on the National Center for Pavement Preservation’s Web 

site at www.pavementpreservation.org, and from the Foundation for Pavement Preservation at www.fp2.org. An additional resource is the American Association of State 

Highway and Transportation Officials’ Transportation System Preservation Technical 

Services Program, which can be visited online at www.tsp2.org. 

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d