Trucking industry owes for bridges.

Byline: George Hermach For The Register-Guard

Recent editorials and articles in The Register-Guard concerning Oregon's serious bridge failures have been commendable. But they have not raised two central questions: Who caused the problem, and who should pay?

The answer to the first question should be obvious. The general public's cars and pickup trucks had absolutely nothing to do with Oregon's bridge failures. Increased heavy truck weights and speeds had everything to do with this destruction. Therefore, the only fair answer to the second question is that the trucking industry must accept this responsibility.

Oregon's roads and bridges were designed and constructed to withstand specific loads and speeds. According to the Oregon Department of Transportation, most of the interstate freeway bridges were designed for 72,000-pound trucks at 55 mph. Other Oregon bridges were engineered for far lower allowable weights. To allow 100,000 pound trucks on our roads and bridges has proven to be disastrous.

To understand the enormous impact of a 100,000-pound truck, the "fourth power law" of physics must be understood: As the weight bearing on a moving wheel increases, its impact on the surface underneath increases by the fourth power. So if weight is doubled, the damaging force is not just twice as much, but 16 times as much. If the weight is tripled, the damage is not just three times as much, but 81 times as much. Increasing truck speeds from 55 mph to 70 mph and 75 mph also exponentially increases the damaging impact.

When ODOT and the state Legislature permitted increases in truck weights beyond the roads' and bridges' original engineered safe load specifications, the seeds of the current disaster were planted. We are now playing with fire, and a possible catastrophic failure could occur at any time. Those who knowingly permit structures to be loaded beyond their design specifications could be held criminally liable.

Rerouting heavy trucks to even lesser strength roadways and bridges is a poor solution. A safer, longer-term solution would be to immediately reduce allowable freeway truck weights to 80,000 pounds, the same as in California. On other routes, 70,000-pound or 60,000-pound limits should be imposed.

More precisely, it would be sensible to reduce weight limits to conform to the loads that roads and bridges were originally designed to carry. Requiring that long-haul, through freight be shipped by rail should also be considered. Such a program could extend the safe, useful life of roads and bridges for decades or more, providing Oregon needed time to complete the costly strengthening and replacement program.

It seems likely that the projected cost of $5 billion will escalate. Adding bond interest, the state could face an obligation in the $10 billion range. It is disheartening that the governor and Legislature are expediting significant tax increases on automobiles to pay for an emergency not of the public's making - and only modest increases to the weight-mile taxes paid by trucks.

The trucking industry loudly proclaims that any weight-limit reductions or tax increases would harm Oregon's economy. Increasing truck freight rates to cover their true operating costs would be of little consequence to motorists, compared to the significant harm of the enormous bill to repair the damage that trucks have caused.

ODOT is constitutionally required to fairly allocate highway costs between autos and trucks. Autos pay 62 percent of those costs, while trucks pay 38 percent. That allocation must be seriously questioned, particularly in the harsh light of the state's bridge example. An independent engineering case could be made for a ratio of 10 percent for cars, 90 percent for trucks. Some retired highway engineers believe the ratio should be 5 to 95.

California highway officials have stated that cars and pickups cause negligible damage to roadbeds. A recent Oregonian article stated, "Trucks are the main cause, according to Mark Hirota, the state's chief bridge engineer, who says increasing speed, not just weight, is a factor."

The public should not be required to subsidize the trucking industry. Each form of freight transportation should compete fairly, without public subsidy. Public hearings should be held to thoroughly inform citizens of the magnitude of the problem, its history and the range of remedies. The public, together with organizations concerned with highway safety, the rights of motorists and equitable taxation, must be well represented.

George Hermach of Eugene, a retired businessman, submitted this statement on behalf of Citizens for Reliable and Safe Highways.