Drivers could share the highways with much heavier trucks if Congress decides that the efficiencies of larger loads trump concerns about road damage and safety.
The Safe and Efficient Transportation Act would raise the maximum weight for commercial trucks that routinely travel on highways to 97,000 pounds in Texas and most other states.
The current threshold in most places is 80,000 pounds unless the truck has a permit to be overweight.
Supporters of the proposal, including many companies that ship household goods in tractor-trailers, argue that it would reduce traffic, decrease fuel use and ultimately keep prices lower for consumers.
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About 200 companies have banded together to support the bill as the Coalition for Transportation Productivity -- including Hershey, Home Depot and MillerCoors, which operates a large brewery in south Fort Worth.
Critics say heavier trucks would severely damage roads and especially bridges, many of which are crumbling and need repairs that the nation can't afford. In Tarrant County, 29 bridges had poor scores on their most recent inspections, the Star-Telegram reported this month after reviewing the National Bridge Inventory.
The review also concluded that, nearly five years after a Minneapolis bridge collapse killed 13 people and injured 145, bridge conditions are arguably worse.
Driving safety is also a concern. Bill opponents say a heavier truck needs 25 percent more room to stop. In 2010, crashes involving large trucks killed 3,675 people, up about 9 percent from the year before, according to the National Highway Traffic Safety Administration's annual report.
Supporters of the bill, however, say the increased limit would apply only to trucks that have a sixth axle. They say such extra equipment gives the heavier trucks essentially the same braking capacity as an 80,000-pound truck with five axles.
While the safety effects can be debated, there is no denying the lack of funds for repairing the nation's aging bridges.
The U.S. has a $70.9 billion backlog of bridge work, and heavier trucks could make the situation much worse, said Andrew Herrmann, president of the American Society of Civil Engineers.
"You have the prospect of shortening the lives of our bridges," Herrmann said. "The trucks with their heavy loads are really what erodes our bridges faster. We're lacking the funds right now to upgrade them."
Trucking on the rise
Even without the bill, record numbers of overweight trucks are already passing through Texas, documents show. Their owners pay $15 to $4,000 for permits, in part to offset damage to roads and bridges.
Last year, 590,980 oversize/overweight permits were issued to trucks -- less than 1 percent of overall truck traffic in the state -- generating $114 million for the state's highway and general funds, according to Texas Department of Motor Vehicles records.
If Congress allows heavier trucks on U.S. highways, many could pass through the state as a matter of course, without a permit.
But heavier trucks don't necessarily pose a threat to the concrete, steel and other weight-bearing components of roads and bridges, an official said.
"It really has to do with how you space the axles," said Richard Goldsmith, a special-projects coordinator with the Motor Vehicles Department.
Texas has no maximum weight provided the carrier has a permit, said another coordinator, Kristy Schultz.
"We issue general permits for loads of up to 254,300 pounds," she said. "Once you exceed that, or if you exceed 200,000 pounds with less than 95 feet of axle spacing, it becomes a 'super heavy load,' and there are multiple steps to go through for a permit.
"It's a three-week to six-week evaluation that includes an analysis of the route by Texas Department of Transportation bridge and pavement engineers and, if you're crossing any bridges, it also requires analysis by an external engineer."
The Texas Department of Public Safety enforces state laws on truck weights, and troopers have portable scales to weigh vehicles on the roadside. Last year, $2.5 million in penalties were assessed for 37 oversize/overweight violations, state records show; $2.35 million was collected in 2010.
The bill would allow states to set their own truck weight limits up to 97,000 pounds for trucks with a sixth axle. Large trucks typically have five axles.
An extra axle would more than offset the additional weight, said Sean McNally, spokesman for the American Trucking Associations.
"A good way to think of it is, you're standing on two feet instead of one," he said.
"The 97,000 pounds on six axles configuration is consistent with offsetting the wear and tear on bridges, and, in fact, it takes trucks off the road."
The bill is sponsored by members of Congress from Maine and Vermont.
Those states, where heavy trucks from logging operations are common, are taking part in a pilot program that allows trucks up to 100,000 pounds on highways for the next 20 years.
Also, states already have the power to control truck weights on nonfederal roads.
The bill would also impose a heavy-vehicle tax of up to $800 per year, depending on truck weight. That would be an increase for many drivers, who typically pay up to $550 a year under existing laws. The money would go into a special trust fund to help states improve bridges.
Proposals to allow heavier trucks have been debated for years. In Texas, the now-defunct Trans-Texas Corridor proposal -- Gov. Rick Perry's vision to crisscross the state with toll roads, railroads and utility lines -- would have allowed trucks up to 120,000 pounds without a permit.
But on interstates and U.S. highways, the quality of bridges isn't the only issue. Fatalities involving trucks are on the rise.
In Texas, 448 people were killed in 2010 in crashes involving commercial vehicles -- which are often, but not always, large trucks. That includes 19 people killed in Tarrant County, state Transportation Department data shows.
But those statistics include many crashes caused by fatigue or errors on the part of the truck driver or other drivers.
And truck weight is rarely the issue in those crashes, McNally said.
"For the longer combination vehicles ... the accident rate for those trucks is the lowest among the entire trucking industry," he said.
"We're talking about our safest, most fuel-efficient vehicles."
Gordon Dickson, 817-390-7796