As States Turn to Pavement Preservation, Road Repair Methods Improve
The economics affecting road building and road repair in the current economy are pretty straightforward. Costs for everything are up, funding is down – and road disintegration continues its natural course, unabated.
Federal funding assistance for new roads and road preservation is now stimulated with an infusion of cash from the American Reinvestment and Recovery Act of 2009. Often, however, red tape and politics add speed bumps and lead to dead ends. Fortunately, some states are finding ways to make it work.
Population growth and economic recovery, when it comes, will only create a greater need for navigable roads, free of hazardous and damaging potholes. The present way we build and maintain roads and bridges will be difficult to sustain – unless new technologies are developed and adopted.
This is a concern that is echoed by the American Association of State Highway and Transportation Officials (AASHTO) in a joint report it issued with the National Asphalt Pavement Association (NAPA) in 2009. It says highway funding is “in an unprecedented crisis.” In summary, the Highway Trust Fund – which comes from the national 18.4 cents per gallon gas tax – is “just about broke,” purchasing power for road building and repair have been eroded by inflation, and the political climate is unlikely to allow increased revenue from drivers (with per gallon taxes and tolls). Environmental concerns, while laudable, are directing more funds toward public transit and railroads, further challenging America’s aging highway system.
VMT – vehicle miles traveled – increased from 2.4 trillion in 1993 to 3.0 trillion in 2007 (the current recession has reduced that slightly to about 2.9 trillion).
Time, weather, and moisture are the enemy of road maintenance, but so is population increase, which is about as likely as rain in Oregon. People use roads, as do manufacturers and merchants who ship products to ever more populated cities and towns. Some facts to consider:
- The current U.S. population of 305 million is projected to increase to 420 million by year 2050.
- VMT – vehicle miles traveled – increased from 2.4 trillion in 1993 to 3.0 trillion in 2007 (the current recession has reduced that slightly to about 2.9 trillion).
- Truck freight is expected to double from current levels by 2030.
- Optimally, road and highway maintenance should receive $166 billion from government funding. Current spending on surface transportation (roads and highways) is less than $90 billion per year.
- The 2009 federal economic stimulus funds add an additional $27 billion to the surface transportation budget, but those funds are to be spent over at least two years, and so the annual allowance remains well below ideal.
It is not enough, not by a long shot, and the problem will only get worse. Solutions are sorely needed.
Preserve and save
Roads are like people in that an ounce of prevention is worth a pound of cure, in that routine maintenance can significantly prolong the life of a road. Preventive maintenance is economically smart, as long as the plan for pavement preservation is smartly devised and implemented.
In 2008, Michigan Department of Transportation Director Kirk T. Steudle told the Pavement Preservation Journal, “It costs $1 to keep a road in good shape for every $7 you would have to spend on reconstruction.” Steudel also noted how bad pavement diminishes road safety, which places further economic burdens on individuals, families, healthcare systems and insurance companies. “It’s another drag on the economy.”
One organization working for solutions is the Foundation for Pavement Preservation (FPP), a non-profit industry group that looks at roads as investments. Rather than regarding maintenance as a cost – how it is typically seen in a budget line item, subject to political costcutting – FPP urges local, state and federal government decision makers to consider money spent on preservation as a means of maximizing the original investment.
Cutting through the red tape
The Illinois Department of Transportation, IDOT, takes the position that preventive maintenance treatments are a means to improve the functional condition of the road network, “reducing the overall rate of deterioration of the pavement asset.” IDOT also prioritizes maintaining a high level of service and minimizing what it calls the “network’s life-cycle cost,” a multi-year calculation that facilitates long-range, comprehensive highway quality management. The state agency also provided guidelines and training to local municipalities on road preservation, and it involved private industry in the overall program.
What Illinois does that many states do not is use federal funds for pavement preservation; other states instead reserve those funds for large projects undertaken every few years, such as new road construction.
This is where it gets tricky: Bidding procedures in Illinois and other states often differ from federal bidding requirements, which often stands in the way of using federal funds for pavement preservation. IDOT particularly encountered difficulties using hot mix asphalt overlays due to its high expense and perceived long-term ineffectiveness.
Pavement preservation best practices
Still, some states are finding ways to do it right. The Asphalt Pavement Alliance makes an annual award to states that maintain roads that are at least 35 years old and which had at least 13 years between paving resurfacing. Other criteria for the award are excellence in design, quality in construction and driver value, factored against traffic levels on the section of road being evaluated for the honor. Here are 2009 award recipients:
Washington State: The Washington State Department of Transportation says its entire highway system would cost $266 billion to replace, including smaller bridges and the purchase of land. Starting from this asset management standpoint, WSDOT invests in infrastructure as a matter of safety, environmental concern and mobility.
WSDOT won its Perpetual Pavement Award for a four-mile section of Interstate 5 near the city of Everett, Washington. This particular stretch of highway handles more than 60,000 vehicles per day, 4,400 of which are heavy trucks.
According to WSDOT’s press release announcing this award, the agency’s “pavement preservation goal is to preserve state highways at the lowest cost per year of pavement life.” WSDOT’s 2007 pavement condition survey found that 93 percent of state-owned roads rate as “fair” or better. The state has budgeted $328 million for 2009-2011 in pavement preservation projects.
Mississippi: This state received its Perpetual Pavement Award for a 10.9-mile section of U.S. Highway 90 in Jackson County, which connects coastal communities of Ocean Springs and Gautier. The road was built in two phases, completed in 1960, with overlays applied in 1973 and 1989 only. In an official MDOT long-range research planning document, it says that pavement preservation is the state’s number one priority among 29 research subjects.
Minnesota: Awarded the Perpetual Pavement Award for a 1970-constructed, six-mile stretch of Highway 71, which received an asphalt overlay in 2005. The Minnesota Department of Transportation (MnDOT) is designating more of the department’s FY 2011 budget to pavement preservation than ever before due to “extraordinary inflation in paving materials and rising project costs.” Criteria for long-lived, cost effective fixes are a life expectancy of 15 years or more.
Tennessee: Honored for five miles of westbound State Route 1-US 11 in Grainger County, the state is known for well-maintained scenic highways, with 14,000 miles under the aegis of TDOT. Statewide they use micro surfacing methods among other technologies, and the American Association of State Highway and Transportation Officers recognized Tennessee in 2009 as number one in the country with the smoothest overall system.
Necessity is the mother of invention
Given the sheer economic and cultural pressures on having a workable road and highway system, engineers and scientists have applied themselves to finding better solutions to road deterioration.
An important program authorized by the U.S. Congress two decades ago began looking for innovations in road design and preservation. Called the Strategic Highway Research Program (SHRP), it is the engine for the development of scores of products and methods, many of which are already in use.
One category of products from SHRP is Superpave®, which combines innovations in asphalt binders and a design/analysis system tied to the volumetric properties of the asphalt mix, all subject to models for mix-analysis tests and performance prediction.
While pavement preservation is often defined as paving resurfacing, pothole repairs traditionally fall into another category. Usually done with hot mix asphalt, this expensive and ineffective method is widely regarded as a bandage approach. However, innovations in recent years, included permanent cold-mix asphalt products, can serve as a permanent repair. Operationally simple, it can be applied as an overlayment, to utility cuts, joint repairs, outer edge repairs, surface patches and in “throw and go” pothole repairs. Because it is a cold mix, work crews have greater time-use latitude – days and weeks instead of hours for hot mix – which ultimately reduces associated labor costs. This cold mix is much more resilient, lasting for years (the experience with traditional hot mix asphalt pothole fillers is they are seasonal bandages, sometimes deteriorating in just a few weeks).
What a handful of states and many road technology researchers show is that there’s more than one way to build and maintain a road – better, cheaper and longer lasting. Innovation – supported by experimentation – is the best bet for smoother, lower-cost highways and byways.
