MISSISSIPPI STATE -- Lowering weight limits on roads may not benefit taxpayers as much as it appears when it puts more log trucks on the road and causes timber prices to fall.

Mississippi law currently has set an 80,000 pound weight limit on roads. A harvest permit can be bought for $25 allowing a 4,000 pound tolerance above this limit. County supervisors can change the weight limit on county roads, and some are considering lowering it to 40,000 or 57,600 pounds.

Dr. Laurie Grace, forestry specialist with Mississippi State University's Extension Service, said running log trucks over poorly-constructed roads causes damage, but the issue is more complex than that.

Grace wrote a computer program to calculate the economic impact reduced road weight limits would have on forest landowners, and found the dollar figure for each county.

"If you reduce the weight limit to 40,000 pounds, the landowner will have to pay to have the timber removed from their land," Grace said. "Most landowners do not like that idea, and in counties with tightly restricted road weights, buyers don't bid on timber because they can't afford to haul it."

A typical log truck weighs 30,000 pounds empty. With the existing weight limits, log trucks can carry 25 tons of logs. Reducing the weight limit to 57,600 pounds means loggers could only carry 13.8 tons of wood.

Less wood per load means more trips, adding to the cost of transportation and slowing the harvest. Harvesting costs are fixed on a daily basis regardless of whether production is slowed to match the reduced trucking loads.

Grace calculated that these costs total $13.68 per ton across the state, which would be reflected in lower prices paid to landowners.

In North Mississippi, landowners would have to actually pay to have pine and hardwood pulpwood removed, and the price of pine and hardwood sawtimber would fall to 75 percent and 53 percent respectively of their previous value.

This is not the only potential impact of reduced weight limits on roads.

"The first impact is to the landowner by reducing their revenue from the sale of timber," Grace said. "Then by reducing the revenue, you could reduce the tax base from which items such as roads and school systems are funded."

Log trucks do impact county roads, but reducing log truck weights impacts county landowners as well.

"A solution to this problem is possible when county supervisors, landowners and those in the timber industry work together," Grace said.