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More potholes, less money – but smarter fixes for crumbling roads

By May 15, 2009 July 8th, 2014 No Comments

Streets and highways are falling apart while local and state governments struggle with other budget crises. Yet our economy is dependent on ground transport of people and goods. The solution? Start with smarter potholes.

Spectacular events with roads and highway infrastructure have a way of getting our attention. For example, the deadly collapse of the I35W Bridge over the Mississippi River in Minneapolis in August 2007 led to a lot of discussion – and finger pointing – on bridge and road safety.

What was clear is we’re not allocating enough money for infrastructure maintenance. Catastrophic consequences can and likely will happen again, just about anywhere.

The bridge was replaced just 13 months later with a safer, modern structure – at a cost of $400 million. But consider the tradeoff: Costs incurred when the bridge was out of commission were calculated by the Minnesota Department of Transportation to be $400,000 per day from lost bridge revenue, increased commuter times and the added burden on roads handling detoured traffic.

The Minneapolis bridge story illustrates a problem facing every municipality and motorist in the United States. Our society and economy are very dependent on the ground transport of people and goods. But there is another visible, costly, always annoying and sometimes dangerous problem – much more extensive but visually less spectacular – that faces motorists and governments everywhere. That problem is potholes, the first and most obvious sign of highway deterioration.

Just as with the Minneapolis bridge, people die from potholes. No national statistics are available, but reported incidents of fatal accidents attributed to blown tires and suspension system failures present a grim picture. (The landmark Hurt Report found in 1981 that roadway defects, which include potholes and pavement ridges, were responsible for two percent of motorcycle fatalities, which some argue has increased over time with further deterioration of roads.) The costs incurred by potholes to individual drivers nationally averages more than $330 for car repairs and as much as $700 for motorists in Los Angeles. Meanwhile, the public expense for road repair and rebuilding is in the billions – and with the aging of America’s superhighway system, all expenses are projected to escalate in coming years. Add to that the distractions of municipal general budget deficits, a bad economy, fuel-efficient cars that generate less in per-gallon tax revenues for state and federal coffers and a “green” impetus to divert transportation money to public transit systems. It’s a perfect storm of highway and byway deterioration.

Maybe all we have in this scenario is ingenuity. Fortunately, some solutions are already in the works. New methods and materials are being tested in the road maintenance business, with promising results.

None of the fixes being tried will completely eliminate the billions of dangerous and costly potholes dotting the nation’s roadways. But as one director of a state department of transportation puts it, it begins by regarding roads as assets, not liabilities.

What about the stimulus money?

The American Reinvestment and Recovery Act of 2009 provides $48 billion for transportation-related projects. But of that, only $27.5 billion is designated for the restoration, rebuilding and expansion of highways. There are about 5000 “shovel ready” projects in all 50 states, but the cost of these is $64 billion.

That doesn’t take into account the approximately 210,000 lane miles of Interstate pavement, much of it already 50 years old, which could use repair not counted in that $64 billion figure. A comprehensive report from American Association of State Highway and Transportation Officials (AASHTO), and TRIP, a national transportation research group, “Rough Roads Ahead, Fix Them Now or Pay for It Later, says that effective road maintenance should be undertaken at a cost of more than $80 billion per year by all levels of government.

Clearly the stimulus money has come at a good time. There just needs to be a lot more of it.

The report urges us to consider the resources used and utility of existing highways as assets. It says that highways, streets and roads have an estimated value of $1.75 billion. Their idea is instead of thinking of roads as expenses, consider them as assets worthy of protection.

“Asset management is a comprehensive approach to ensuring the most cost-effective return on investments for operating, maintaining, upgrading, and expanding transportation systems,” say the report’s authors. “It starts from the assumption that the nearly four million miles of public roads are a valuable national asset, essential to the vitality of the American economy.”

Which touches on why stimulus funding for road maintenance is about more than just the short-term hiring related to construction. Consider the freight industry and businesses producing goods that long-haul trucks carry: every Interstate mile handles 10,500 trucks carrying $25 billion in goods each day. Of all goods transported in the U.S, 80 percent of it by weight travels by truck. Large commercial truck traffic – the heaviest vehicles – increased by 50 percent between 1990 and 2007.

Looking at the safety side of this argument goes beyond potholes damaging wheel rims on cars and trucks. More than half the nation’s school children, about 24 million students in kindergarten through 12th grade, ride in 450,000 buses 180 days of the year. Every 20 seconds a fire department sends one or more vehicles out to respond to an emergency. Ambulances make about 164,000 trips per day in the U.S. Deteriorating roads, including potholes that seemingly appear out of nowhere, slow their trips and sometimes are directly responsible for tragic accidents.

These incidences of human safety and economic costs are concentrated in urban areas. It’s the cities and suburbs where road conditions are the worst. It’s also where populations are expanding fastest. Utah, particularly its metropolitan areas, had a 47 percent population growth over the last two decades, leading to a 71 percent increase in miles driven; unfortunately, highway capacity grew by only 4 percent.

A hopeless situation? Not entirely.

Get your pothole priorities straight: Spend $1 now, not $7 later

The old saw, “an ounce of prevention is worth a pound of cure” never had a better example than road maintenance.

Michigan Department of Transportation Director Kirk L. Steudle puts it this way: “It is important to slow the rate of decline in the good road so that it stays good rather than slipping into fair or poor condition.” He calculates that spending $1 to keep a road in good condition prevents spending $7 to reconstruct it once it has fallen into poor condition. Taking the asset management approach, “It isn’t a computer software program, finance and accounting practices, or a pavement preservation program,” Steudle says. “Asset management includes all that and more.”

The mechanics of road construction and eventual pothole development illustrates this. A new road is generally asphalt pavement layered over crushed stone on top of soil. When cracks occur in the pavement the soil layer erodes, leaving gaps or holes. Freezes, thaws, heat and heavy traffic create shifting and then buckled pavement. Traffic on top the buckling cracks the pavement further, creating potholes that grow with time (this is why potholes often appear overnight, even though in the sub-pavement the process begins days, weeks or months beforehand).

Catching pavement cracks before they allow moisture to seep into the sub-base is very helpful in preventing road deterioration. But in a world of scarce dollars, that’s not what often happens. Instead, a “worst first” approach is often employed. This is where the most potholed, buckled and impassible streets are given priority attention.

Catching pavement cracks before they allow moisture to seep into the sub-base is very helpful in preventing road deterioration. But in a world of scarce dollars, that’s not what often happens. Instead, a “worst first” approach is often employed. This is where the most potholed, buckled and impassible streets are given priority attention. Such streets are simply non-functional, the roads that generate the most phone calls to city streets departments and local politicians. This then becomes the $7 fix, where $1 spent weeks, months or a couple years earlier would yield better road conditions and a lot less motorist/taxpayer anger.

Technically speaking, preventive measures take several forms:

Data collection: Know the conditions of roads, using advanced tools such as the “pathway profilers” in use by the Nebraska Department of roads to assess the severity and extent of pavement distress.

Data assessment and resource allocation software: After road and bridge conditions are gathered, that data can be analyzed by software such as the dTIMS CT program employed by the Utah Department of Transportation. This helps the department prioritize where preventive maintenance will be most effective even while alerting them to where the most advanced problems exist.

Sealers: Chip, slurry, fog, crack and joint seals applied early to new cracks keep pothole-inducing moisture from the sub pavement. The Oregon Department of Transportation expects to save $16 million per year with its chip-seal preservation program.

Advanced pothole repair technology: Where traditional hot mix pothole fillers are often expensive, inefficient and ineffective – failing in a matter of weeks, sometimes never really working at all – new technologies are emerging that change the equation. An article in Tennessee Public Works magazine (January/February 2002) reported on the experience of a public works director in Millersville, TN, a suburb of Nashville. He tested EZ Street brand cold asphalt, which can be applied with less surface preparation – including in standing water –across a wider range of air temperatures. The product can be applied more quickly than traditional hot mix, with greater work crew efficiency, and it lasts longer.

The mix is more expensive per ton, but creates cost savings over time, says the city streets chief: “I did the math. If it cost 10 dollars to patch a pothole one time, and I had to patch it 12 times a year, then 20 or 30 dollars to patch it once a year would save me both labor time and material costs. Using this product we are able to do a better utility cut and do it faster. We can cut a road, pack the sub grade, and apply EZ Street and not have to worry about it coming out of the hole.”

As it often happens, smaller states and municipalities are willing and able to try new methods for addressing public works challenges. When those methods prove effective over time – as many already are doing – larger entities with more roads and bigger bridges would be wise to follow their lead.