When does a big rig get too big?

• Big truck

A truck drives west Friday on state Highway 38 east of Mitchell. There are competing proposals in Congress to freeze or raise the truck weight limit on federal highways. (Chris Huber/Republic)

Talk about it

Do heavier trucks damage roads?

The question is a no-brainer for Davison County Highway Superintendent Rusty Weinberg, who said county roads designed for tractors and small farm trucks are being chewed up by semis with gross vehicle weights occasionally exceeding 100,000 pounds.

“I just want my roads to hold up,” Weinberg said, “but everything keeps getting bigger.”

The lack of money to repair roads has been an ongoing problem for Davison as well as other South Dakota counties as federal highway aid trickles down to states each year.

The load-limit issue has reached Congress, where lawmakers are weighing in on limits for the federal highway system. There are competing proposals to raise the federal load limit or freeze it at the current level.

“The higher weights are a concern if those heavier trucks leave the federal and state highways to make deliveries onto the county road system,” Weinberg said, because local roads aren’t designed for those heavier loads.

The pending battle was featured in a recent article on the National League of Cities website.

The league opposes increases in truck weight limits unless the increases are accompanied by increases in the heavy truck user tax.

The league also asserts that no changes should be made at the federal level until the impact of increased truck length and width standards on highway costs and safety is assessed and reflected in highway user fees and safety regulations.

Since 1991, 18-wheelers have been limited to 80,000 pounds on federal highways.

Sen. Mike Crapo, R-Idaho, is pushing support for his Senate Bill 747, which is co-sponsored by Sens. Susan Collins, R-Maine, and Rob Portman, R-Ohio. It would let states allow trucks with a gross weight of 97,000 pounds to operate on federal highways if the trucks heavier than the existing limit have a minimum of six axles and meet some other criteria.

Idaho currently allows for 97,000-pound loads under special permitting and axle options, Crapo said in a release supporting the proposed legislation. His arguments are that higher limits will reduce the number of trucks needed to transport loads, thereby saving fuel, reducing shipping costs and giving businesses a competitive edge.

Those who rail against raising the federal weight limit believe keeping weight down will help to preserve stressed federal highways and the estimated 23,550 of the 116,523 bridges on the national highway system that are rated structurally deficient or functionally obsolete. They also say heavier trucks are a danger because they’re more difficult to stop and control.

Legislation freezing the current 80,000-pound limit on federal highways has been introduced by U.S. Rep. Jim McGovern, D-Mass., and Sen. Frank Lautenberg, D-N.J. The Safe Highway and Infrastructure Preservation Act — H.R. 1574 in the House and S. 876 in the Senate — has 61 co-sponsors in the House and four cosponsors in the Senate.

South Dakota’s three congressional delegates are not among the co-sponsors of either competing bill. U.S. Sen. Tim Johnson, D-S.D., believes the subject warrants more time for consideration.

“I think that the impacts to the structural integrity of highways and bridges, as well as possible effects for public safety, need to be better understood before considering changes to truck weight limits,” he said in a recent statement.

South Dakota Trucking Association President Myron Rau, of Sioux Falls, said the trucking industry has struggled under the 80,000-pound weight restriction for 18-wheelers since 1991, and his association wants the feds to loosen the reins.

“We want states’ rights to be returned,” he said, “so the state can make decisions based on South Dakota’s needs.”

The one-size-fits-all system of weight regulations just doesn’t work, Rau said — a comment echoed by U.S. Rep. Kristi Noem, R-S.D.

“Rural infrastructure varies dramatically from urban, and I believe states should have more say in regulating their roads and highways,” Noem said in a statement.

U.S. John Thune, R-S.D. did not respond to requests for a comment on the issue.

Funding debated

Beyond the trucking industry’s struggle with weight restrictions, Rau said the industry also is struggling with high fuel costs, driver shortages and overregulation. He decried positions such as those held by the National League of Cities, which asserts that higher weight limits should be accompanied by higher taxes on large trucks.

“We already pay 50 percent of the highway fees in this state and we drive 14 percent of the miles, and they want to make our taxes higher,” Rau said. “We want to pay our fair share, but we already are.”

The current federal system of highway funding is broken, he said, and a better way must be found to pay for highway construction and maintenance.

Counties, cities and townships get road funds from license plate fees; the state gets its money from a 3 percent excise tax on car sales and fuel taxes; and federal highways get money from fuel taxes. The feds, said state Rep. Mike Vehle, RMitchell, get 18.4 cents per gallon from gasoline and 24.4 cents a gallon from diesel taxes.

“That federal tax hasn’t been increased since 1984, so the federal trust fund that pays for road construction is running into problems,” Vehle said, and state taxes haven’t been increased since 1999.

Newer vehicles use less fuel, which means less money is being collected from fuel taxes at a time when extra cash is badly needed to fix roads.

The issue of highway funding and maintenance has been hotly debated lately in Congress. House and Senate lawmakers voted Thursday to extend U.S. highway programs through June 30 while work continues on a long-term transportation bill.

Vehle believes that the trucking industry should pay more.

“If you look at the tonnage that goes across our roads, that’s where the wear and tear is.”

‘Weight is weight’

Rau said many of the weight regulations placed on trucks are not based on good science.

Large rigs, which have more axles and tires, spread the load and do less damage than heavily laden vehicles that concentrate a load’s weight on just a few tires, Rau said, explaining his support for higher load limits.

Slower speeds for trucks don’t make sense either, he said, because they allow pavement to be subjected to heavy loads for a longer period of time. Oftentimes, slower speed limits are imposed during the spring along with temporary load limits on local roads.

Highway Superintendent Weinberg said he has heard all the technical arguments for loadspreading and for increasing or decreasing speeds.

“All I know is that weight is weight, and heavy loads damage my roads,” he said.

Maj. Ken Urquhart, of the Minnesota State Patrol, said “heavier isn’t always bad if it’s done properly, but overloaded axle groupings can do damage.” He said his state is supporting the trend from two axles on the rear of trailers to three axles, to limit road damage.

While Minnesota has carrier enforcement troopers on the road to periodically check for overloaded trucks, a 30-yearold state law also gives troopers the authority to review scale tickets at grain elevators throughout the state.

“We usually don’t see much in the way of violations, but it gives us intelligence about what’s being moved,” Urquhart said.

If a pattern of overweight loading is discovered, troopers contact the truck’s owner to determine the responsible party. Violators can be hit with civil penalties.

SD impact considered

Greg Fuller, director of operations for the South Dakota Department of Transportation, said he has not done an in-depth analysis of what effect higher federal truck weight limits would have on state roads.

“In and of itself, an increase to the allowable gross weight of a truck is not such a significant issue,” Fuller said.

“The issue would be how they configure those trucks and what they allow on their axles.”

The legislation proposing higher weight limits on federal highways also specifies that trucks carrying the higher weights would need a minimum of six axles.

Trucks must conform to gross vehicle weight postings as well as postings for bridge weight limits. A driver must use a “bridge formula” to determine if his truck and load can safely cross a bridge.

The formula includes not only the total weight of the truck and the load but also the how that load is distributed. Calculations consider the number of axles and the distance between those axles.

A heavily laden truck with three axles can place more stress on a bridge than a truck with five or more axles that spreads out a load, Fuller said.

The typical tractor-trailer has five axles: a steering axle, a dual axle that supports the rear of the cab and the front of the trailer, and a dual rear axle.

Axle configurations can vary, but a five-axle truck under 80,000-pound load restrictions typically would have 12,000 pounds on the front axle and 34,000 pounds on each of two, dual rear axles.

The Senate legislation that proposes bumping the maximum truck gross vehicle weight from 80,000 to 97,000 pounds would require six axles for the heavier trucks. It also would boost the load limit on the triple rear axle package from the current 43,000 pounds to 51,000 pounds.

‘We have to have roads’

Higher loads have always been possible under certain circumstances, Fuller said.

Drivers must secure special permits to run trucks with loads higher than 80,000 pounds.

Fuller said he has known of trucks with multiple axles with gross weights of 135,000 to 145,000 pounds.

If federal highways are approved for higher weights, some bridges may have to be posted with new weight limits.

“Provided they meet the bridge load formula in the motor carrier handbook, there is no gross weight cap on those loads,” Fuller said.

Mitchell resident Chet Edinger said his family’s Edinger Brothers Partnership depends on its trucks as it farms in Davison, Aurora and Sanborn counties. He believes it’s too simplistic to say that weight equals damage.

Multiple trips do more damage to roads, Edinger said.

“Fifteen trips over the same roads do more damage than 10 trips with heavier loads.”

Edinger said South Dakota farming requires good roads.

“We have to have roads, and the real issue is farm-to-market roads throughout our counties, which are in terrible shape.”

He, like Rau, believes that a more equitable way must be found to fix roads.

Edinger believes one answer would be a special tax.

“If 100 percent of the money was dedicated strictly to the repairs of roads and bridges, I would not be against it, and I don’t believe the average owner of farm ground would be, either,” he said.

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