Highway Pavement Performance Improves
Our nation is paved with nearly 2.3 million miles of interstates, freeways, expressways, arterials, collectors, and local highways. Including new highway construction, reconstruction, and routine maintenance, roughly half of all monies spent on highways in the U.S. are spent on pavement.

In 2001, nearly $42 billion was spent on highway pavement construction, according to Bill Buechner, Vice President of Economics & Research with the American Road & Transportation Builders Association (ARTBA).

"What's a highway?" muses Byron Lord, Acting Director of the Federal Highway Administration (FHWA) Office of Pavement Technology. "It's pavement. We can confidently say that in the U.S. we have a paved road from nearly anywhere to everywhere."

But the FHWA is far from resting on its laurels. Lord is on a crusade to prepare pavement systems to meet the challenges of the 21st Century. "Our interstate system is 30-plus years old and a lot of the pavement needs replacement. We have an incredible opportunity now to make vast improvements in the pavement stock in this country."

To this end, the FHWA is, first of all, developing tools to aid decision-makers, designers, builders, and operators-with their participation-so that more durable, longer-lasting pavement materials are developed. The FHWA is also looking at means by which construction quality can be enhanced, and pavement maintenance can more effectively provide a long-lasting, safe, smooth ride.

"Our vision is that pavement systems will be designed, built, and preserved using performance-based specifications," says Lord, who points out that there is no common denominator on pavement performance in the pavement industry today.

Building the Common Denominator
In the past, pavements were typically designed with a 20 or 30-year design life. For highways that have already seen a 100 percent increase in the number of vehicles and a 400 percent increase in freight over the last 30 years-and are projected to see further growth in vehicle miles traveled and ton-miles of freight carried-this is no longer good enough.

The FHWA, in conjunction with the American Association of State Highway and Transportation Officials (AASHTO) and pavement organizations such as the Asphalt Pavement Alliance (APA), the American Concrete Pavement Association (ACPA), and the Concrete Reinforcing Steel Institute (CRSI) are developing "extended life" pavement systems with 40-year, 50-year, or maybe even longer design lives.

Today, more than ever, pavements must provide long lasting, uninterrupted, high levels of service. America's highway users are demanding that we "get in, stay in, get out and stay out." Extended life pavements assure we will "stay out" while continuing to prove safe, reliable transport of goods and people.

According to the APA, "perpetual pavement" is defined as an asphalt pavement designed and built to last longer than 50 years without requiring major structural rehabilitation or reconstruction, and needing only periodic surface renewal in response to distresses confined to the top of the pavement. In other words, the surface may need to be milled up and repaved, but the base layers remain in place over the life of the pavement.

APA is also promoting stone matrix asphalt, a strong stone skeleton held together by a rich asphalt cement, originally developed in Europe, that prov-ides a strong, skid resistant, quiet ride particularly well-suited to roads subject to heavy loads and high traffic volumes.

"The world's premier pavement test track, located at the National Center for Asphalt Technology, has the potential to save taxpayers $1 billion a year in highway costs through practical research," says Mike Acott, President of the National Asphalt Pavement Association.

Concrete pavement is also increasing in popularity, due in part to ACPA's new educational programs and research efforts. "ACPA is making improvements and refinements in every aspect of pavements: materials, design recommendations, and construction," says Valentin Riva, President and CEO of the ACPA.

In the past several years, the concrete pavement industry has substantially refocused its research efforts and currently is leading more than $12.5 million in third-party highway research through a partnership effort with FHWA, TRB, as well as state transportation officials and academia. This effort is being managed by the Innovative Pavement Research Foundation, which is jointly sponsored by concrete industry groups.

CRSI also funds concrete pavement research, focusing their efforts on continuously reinforced concrete pavement (CRCP), which is, simply, concrete pavement that is reinforced with continuous longitudinal steel reinforcing bars that control the width of transverse cracks and hold them closed.

"Many states, like Illinois, Texas, North and South Dakota, Virginia, and others recognize that CRCP provides outstanding long-term value because of its greater durability, longer life expectancy, and minimal maintenance requirements," says Michael Plei, Manager of Transportation with CRSI.

Restore and Preserve, Not Replace
The vast majority-typically over 80 percent-of monies spent on highways goes to rehabilitation and maintenance, according to ARTBA's Bill Buechner. New highways, widenings, and relocations constitute less than 20 percent of the expenditures.

Although FHWA and others are working toward developing tools that will improve new pavement construction techniques, their larger focus is on pavement preservation.

"The traveling public demands safe, quiet, smooth highways. Recent advances in pavement technology enable a variety of economical, fast solutions to both new construction and maintenance requirements," says Peter Grass, President of the Asphalt Institute.

There are a number of surface treatments used to preserve the condition of a pavement and prevent a decline that would ultimately require pavement replacement. These include micro-surface chip seals, slurry seals, crack seals, and joint maintenance techniques.

Pavement maintenance has traditionally been based on repairing cracks, potholes, and ruts, for example. Byron Lord explains that the problem is that you can't proactively manage a failure-based system because you're only responding to distress after it has occurred. "If we are to effectively preserve uninterrupted high levels of service, we must keep the pavement condition high and perform preservation before it deteriorates."

So, in addition to pavement preservation techniques, the FHWA Office of Pavement Technology is strongly supporting a shift to an asset-based management approach, which it considers a powerful tool to make informed decisions based on pavement performance criteria.

In an asset management based program, repair-or-replace decisions are made based on facts about the condition of the pavement and analyses based on solid economic criteria, including initial capital cost, long-term maintenance cost, and cost to the user.

"We are not here just to build roads," says Lord. "Rather, we have a very serious commitment to reducing fatalities and improving the flow of people and goods through long-lasting, safe pavement. It takes a new way of looking at our pavement material and management systems to accomplish these goals." This is FHWA's vision for pavements for the future.

From a gateway to the nation's capital to the "Crossroads of America," CH2M HILL combines technical excellence with environmental sensitivity and community consciousness to deliver high-value transportation solutions.

A cultural and historic landmark that typifies the grandeur of the nation's capital, the Lincoln Memorial Circle in Washington, DC, is a major attraction for visitors from around the world. CH2M HILL was selected by the Eastern Federal Lands Highway Division to prepare preliminary and final plans for the rehabilitation of this unique traffic circle and its approaches.

The project contains 6,800 linear feet of roadways, involving reconstruction of the eastern third of the circle from an asphalt roadway to a colored concrete pedestrian plaza, construction of aesthetic bus pads, drainage rehabilitation, replacement of granite curbing and sidewalks, traffic signal work, and repair of the roadway approach on the east side of the Arlington Memorial Bridge.

Historic, cultural, and aesthetic concerns are of extreme importance. All design features are being developed in accordance with the National Park Service Streetscape Manual and the Cultural Landscape Report. Historic preservation of the integrity of original roadways includes constructing granite curbs along all new roads.

To address present-day concerns, the proj-ect is also being modified to include security features to protect the Memorial and the public.

On a larger scale, but reflecting historic ties of its own, is CH2M HILL's $145-million I-70/I-75 Interchange reconstruction project near Dayton, Ohio. One of the Ohio Department of Transportation's largest projects, it will transform a substandard interchange designed for 1960s traffic volumes into a safe, modern and efficient interchange.

Phase 1 of the three-phase final design includes a new compressed diamond interchange 1.5 miles south of the I-70/I-75 Interchange, known as the "Crossroads of America." Phases 2 and 3 deal with the main interchange and include new exterior directional ramps, a new two-lane flyover ramp bridge, two interior directional ramps, one loop ramp, and highway widening.

Even a sulfonic acid-based liquid stabilizer injected 4 ft into the subgrade was not sufficient and significant rutting (more than 6 in.) of the subgrade occurred.

Tensar Earth Technologies was consulted to provide a geogrid-reinforced subbase section that would provide sufficient support both during construction and after the pavement was put into service. It recommended a pavement section incorporating a recycled concrete aggregate base underlain by one layer of Tensar BX1200 biaxial geogrid and one layer of non-woven geotextile.

Heavy rainfall during pavement construction significantly reduced the subgrade support. The on-site inspectors were extremely skeptical that the pavement section would provide a stable working platform for the paving operation. After placing the Tensar biaxial geogrid and concrete aggregate, all were made believers! The geogrid-aggregate composite created a "bridge" over the weakened subgrade and enabled TxDOT and the contractor to get back on schedule.

Soil conditions along a 100-mile east-west swath of central Texas can be as varied as the state of Texas itself: ranging from solid limestone to highly expansive clays. Preliminary pavement design for the new Texas Turnpike Authority's State Highway 130-a reliever route to attract traffic from other nearby congested roadways-took a "one size fits all" approach, considering the worst-case soil conditions.

PBS&J, a leading provider of infrastructure planning, engineering, construction management, and program management services, was originally one of ten design consultants for a 10-mile segment of SH-130. PBS&J is now serving as the construction manager for the "Big T" (State Highway 45/Loop 1) near Austin.

Early in the construction management phase, PBS&J took a close, "value-engineering" look at the subgrade conditions along the entire 21-mile length of the Big T, and proposed two main alternative pavement sections tailored to the specific site conditions.

Adjustments to the pavement section, layer thicknesses, aggregate gradations, and placement specifications resulted in a significant cost savings to the project and more durable pavement over the life of the highway.

US-131, through downtown Grand Rapids, MI, is the fourth busiest freeway in the state, carrying 120,000 vehicles per day. For 1.2 miles-right through the heart of downtown-US-131 makes a tight S-curve around 100-year-old buildings, spans 1,900 ft over downtown, and then makes a 1,000-ft, 13-span leap over the Grand River. Built in the 1960s, the Michigan Department of Transportation (MDOT) hired Consoer Townsend Envirodyne Engineers (CTE) to redesign it.

The existing segment consisted of six 11-ft lanes without shoulders, short ramps, and five aging steel beam bridges requiring continuous maintenance. In addition to correcting structural deficiencies, the project included modified geometrics, wider shoulders, weave-merge lanes for ramp traffic, new long span steel plate girder bridges and extensive aesthetic improvements to complement the downtown area.

With the demolition of one aging city-owned storage building, the design team was able to significantly improve the horizontal alignment and increase design speed by 5 mph. Embankments were converted to retaining walls, allowing an additional lane in each direction. The S-curve structures were the first in Michigan to incorporate ride quality standards. CTE and MDOT jointly developed a special provision that resulted in a significantly better driving surface. This was significant, since bridge deck compromised approximately 50 percent of the total project length.

To improve wintertime driving safety, a fixed, fully automatic anti-icing system was embedded into the pavement. When road conditions warrant it, spray nozzles apply anti-icing fluid to the entire road surface prior to a freezing point. The fluid is less corrosive to bridges and vehicles than standard road salt, is biodegradable and environmentally safe. This fixed anti-icing system is the largest installed system of its type in the U.S., and it is the first anti-icing system that treats roadway surfaces as well as bridge decks.

CTE met the original design schedule and through MDOT's dedication to partnering the reconstructed freeway opened to traffic nine months ahead of schedule.

The Illinois Department of Transportation (IDOT) has consistently ranked the intersection of Cicero Avenue (Route 50) at 127th Street and I-294 (the Tri-State Tollway) in the Chicago area as one of the state's 10 most dangerous intersections.

Stanley Consultants, Inc. designed the intersection reconstruction, which included widening the intersection from five to nine lanes, constructing a new curved flyover bridge, widening and redecking three bridges and constructing three new tollway ramps.

Ken Eng, plan preparation engineer for the IDOT, said, "The project is a benefit to the overall community and the Village of Alsip. It improves intersection safety and improves the operation of the intersection, which is no longer a major congestion point."

But lurking beneath the site was a problem that no one anticipated: what was previously identified as three significant sinkholes turned into one giant sink hole requiring 100 times more grout, which ultimately delayed the project nearly one year. PENNDOT asked American Infrastructure subsidiary Allan A Meyers to accelerate the work so that the project could be completed in 2001.

Intense cooperation of all trades personnel and field project management, the sheer determination of the field forces, and their willingness to work long days and weekends were the determining factors to meeting PENNDOT's accelerated schedule. The travelers and commuters on Route 202 received a nice Christmas present: the completion of six major ramps on December 13 which were originally scheduled for December 21.

As Andrew Warren, PENNDOT District Administrator said in a commendation letter to Ross Myers, President and CEO of American Infrastructure, "The efforts of you and your staff to resolve these unforeseen issues while still completing the project as scheduled . . . was greatly appreciated by me," speaking, no doubt, for all who use the road.

The Asphalt Pavement Alliance (APA) is a coalition, formed in 2000, of the Asphalt Institute, the National Asphalt Pavement Association, and the State Asphalt Pavement Associations. The APA's mission is to further the use and quality of hot mix asphalt pavements through research, technology transfer, engineering, education, and innovation.

One of the APA's key research and development focuses is perpetual pavement, a hot mix asphalt pavement designed to resist bottom-up fatigue cracking by combining the appropriate thickness with the right material properties and a high-quality hot mix asphalt ride surface that can be periodically replaced as needed.

Another major advantage of hot mix asphalt pavement is that it can be built quickly and resurfaced even more quickly, thereby reducing impacts to the traveling public.

A number of cooperative efforts are currently underway across the country (many in conjunction or cooperation with the APA) to devise and refine designs and specifications for the construction of Perpetual Pavement, which, if properly maintained, should last longer than 50 years without requiring rehabilitation or reconstruction.

The APA offers a wealth of technical information, most of it online at www.asphaltalliance.com, to those interested in the design and optimal construction techniques of hot mix asphalt.

T-REX is a pioneering, $1.7-billion design-build mega project, combining highway and light rail transit, constructed and financed under one plan. This unique Denver-based project is turning heads across the nation, especially as word spreads of its on- time and under-budget success.

Short for "Transportation Expansion," T-REX transforms congested Colorado Interstates 25 and 225 into wider, more efficient transportation corridors through the inclusion of new light rail transit with significant highway improvements.

Further testament to its uniqueness is the project's cooperative approach among agencies, bringing together the Colorado Department of Transportation, Regional Transportation District, Federal Highway Administration and Federal Transit Administration, as well as several cities, counties and business districts.

"This project represents the first time, in any state, that a state transportation department and a transit agency have come together to build one project under a single financial plan to provide travelers with integrated transportation system options," said Randy Pierce, T-REX consultant principal-in-charge and project manager at Carter & Burgess, Inc., which provides program management services for the design-build contract.

"By combining the multiple modes of transportation, more commuters can move safely and expeditiously through the same space at the same time than would otherwise be possible," Pierce said. T-REX accomplishes such a feat and should serve Denver well, as it prepares for an expected population increase of more than 1 million residents in the next 20 years.

"We are building this proj-ect with the public's interest, objectives and needs in mind, shaped by extensive public input," Pierce said. "Integrating the design and construction phases for speed and economy, T-REX has set demanding goals for quality, schedule and budget while minimizing the inconvenience to the public."

Union Paving & Construction Co., Inc., of Irvington, NJ, chose EFCO formwork for the Route 21 reinforced concrete viaduct replacement project near New Jersey's congested Newark Airport.

The viaduct, with complex interchanges at each end, provides a vital link to the airport and to Interstate I-78, US 1 and 9, and US 22 and local streets. Extreme space limitations below the viaduct-including complex railroad and roadway crossings-made EFCO's Plate Girder® Form System virtually the only system that would work.

Union Paving & Construction built the forms and assembled the reinforcing steel cages on the ground, lifted both into place, and poured the concrete with minimal disruption to the live traffic below.