WASHINGTON -- Marchelle Wood's worst fears have already come true.

She lost her daughter, Dana, six years ago when a heavy truck slammed into her car as she was driving back to school.

"He broadsided her, went right between her tires," said a tearful Marchelle, pointing at the driver's side of her daughter's car. "And this is where she was sitting."

Dana's crushed and rusting convertible sits in the backyard of Marchelle's mother's home underneath a tarp. Not many people have seen it, certainly not Marchelle's mom or her two surviving children. Despite all the painful memories the car dredges up, Marchelle says she can't imagine getting rid of it.

"This is where my daughter died, and this was the last place she was." Marchelle said. "It's just another part of her I can't lose."

The latest numbers from PennDOT show that more than 7,000 crashes involving big trucks took place in the state in 2007. 178 people died.

Now, Marchelle and her husband, Franklin -- who live in Maryland -- are waging a personal battle against members of the trucking industry who are angling to get some federal regulations changed. They want Congress to give them the green light to increase truck size and weight from 80,000 pounds to 97,000 pounds.

This month, Congress is expected to begin debate on a massive surface transportation bill. The Safe, Accountable, Flexible, Efficient, Transportation Equity Act: A Legacy for Users (SAFETEA-LU) will contain hundreds of billions of dollars for surface transportation and transit projects around the country. The American Trucking Association said this reauthorization period is a good time for the federal government to revisit the issue of truck size and weight.

"Those who suggest that safety would be compromised just don't understand the facts," said David Osiecki of the American Trucking Association.

Statistics show that fatalities involving large trucks are on the decline. According to the U.S. Department of Transportation, there were 4,808 deaths in 2007, down from 5,240 in 2005.

The American Trucking Association argues that bigger trucks would actually increase safety because there would be fewer of them on the road, emitting less carbon emissions.

"Fewer trucks is good for you because you're not having to travel with as many trucks on the highway. Congestion is a huge issue in our country," Osiecki explained. "So, the fewer the trucks, the better the situation is for the environment."

The Woods disagree.

"They want to increase their efficiency at the expense of people who ride the highway," said Franklin Wood.

The move to freeze truck sizes has some support on Capitol Hill. In two weeks, lawmakers plan to reintroduce legislation that would prevent heavier trucks from traveling on federal highways. However, a similar bill failed to make it through Congress last year.