Overweight trucks damage roads, bridges

Illegally overweight vehicles cause an estimated $12 million to $53 million a year in uncompensated damage, state officials estimate.

That amount is not covered by fines truckers pay when they get caught nor by fees truckers pay for permits to exceed weight limits.

Arizona enforcement officials estimated 30 percent of trucks operate in excess of legal weight limits — by far the highest among a dozen states that provided estimates in response to a nationwide survey. Researchers said 15 percent is a better guess.

More than a half-million overweight trucks are allowed onto the nation's roads and bridges — an increasingly routine practice that some officials say is putting dangerous wear and tear on an already groaning infrastructure.

In interviews with The Associated Press, some experts warned that the practice of issuing state permits that allow trucks to exceed the usual weight limits can weaken steel and concrete, something that investigators say may have contributed to the Minneapolis bridge collapse that killed 13 people on Aug. 1.

"We talk about this all the time, and the fear that we have is that we're going to have the same sort of disaster here that happened in Minnesota," said Don Lee, executive director of the Texas Conference of Urban Counties.

In Arizona, Gov. Janet Napolitano ordered a review of all state bridges in response to the Minneapolis disaster. After officials inspected 170 of them and reviewed records on more than 630 others, Arizona Department of Transportation Director Victor Mendez pronounced them all safe and accelerated repairs on three bridges.

The rough estimate of up to $53 million in uncompensated costs attributed to overweight trucks in Arizona was reached last year in a study by consultant Sandy H. Straus and project manager John Semmens of ADOT's Transportation Research Center.

"Looking at a number of different measures, it's pretty obvious to me that the heavier vehicles are not paying sufficient fees and taxes to cover the wear and tear they impose on the pavement. The overweight vehicles are just one slice of that," Semmens said Monday.

Until the mid-1990s, Arizona taxed trucks based on their weight and distance traveled.

"Successful lobbying by the trucking interests did away with that, and I think as a result the replacement diesel taxes are not sufficient," Semmens said.

Arizona budgets about $6 million a year to have officials set up mobile weigh stations to catch violators.

The weight limit for nearly all interstate highways is 40 tons. According to a government study, one 40-ton truck does as much damage to the road as 9,600 cars.

But permits frequently allow vehicles to exceed that amount by 2 tons in Texas and sometimes as much as 85 tons in Nevada. Some states grant one-time permits that allow trucks to be considerably heavier.

Engineers liken the effect of heavy trucks on a bridge to bending a paper clip: It can bend again and again without breaking, but eventually it will snap.

Around the country, many transportation officials dismiss such fears as overblown and say roads and bridges are safe, though some express concern that not enough is being spent to repair the damage done by extra-heavy trucks.

Many states charge fees ranging from $12 to $1,000 for overweight-load permits, depending on the weight of the load. In theory, those fees are supposed to offset the highway damage.

The study by Arizona transportation officials found that Arizona is selling more overweight permits per heavy-truck mile traveled and issuing more citations than most neighboring states. The report said that implies the state is "relatively aggressive" in efforts to make overweight vehicles get permits and to catch violators.

In 2003, the state issued 83,651 permits and cited 28,457 violators.

Arizona Trucking Association officials had no immediate comment Monday.

Darrin Roth, director of highway operations at the American Trucking Association, said it is not fair to put all the blame on trucks, because permit loads are a tiny proportion of total traffic.

States allowed more than 500,000 overweight trucks to traverse the nation's bridges and highways at will in the past year, according to an AP review of figures in all 50 states. Those permits were good for an entire year. While 10 states do not issue yearlong permits, all states hand out shorter-term permits good for a few days, weeks or months. Those add up to more than 1.8 million permits not included in the AP's count.

On StarNet: An interactive map offers state-by-state information on the number of permits issued for overweight trucks at azstarnet.com/multimedia