NASHVILLE - U.S. Rep. Jim Cooper (D-Tenn.) on Tuesday signed a bipartisan letter to President Barack Obama asking the White House to support a six-year transportation bill to address a wide range of road and bridge projects.

It's a positive step for what has been a controversial bill, said Tim Marema, vice president of the Center for Rural Strategies. However, he said he is concerned that the proposal could have a negative impact on rural communities.

He says metropolitan areas such as Nashville, Knoxville, Chattanooga and Memphis would see little change - but the proposal raises the population threshold for local input on construction decisions from 50,000 to 200,000.

"The idea with this being public money is that it should benefit as many of us as possible and help create opportunity for all of us," Marema said.

Tennessee state law will continue to give locals a voice in transportation decisions in their areas, Marema says, but he thinks that in many areas, rural communities will lose some of their influence over how transportation tax dollars are spent.

According to a recent report, more than 11 percent of the nation's bridges need timely repairs to avoid unsafe structural deficiencies. The letter to Obama addresses those concerns.

Marema said the bill is long overdue, but rural communities should not be left out.

"When you exclude certain parts of the community from that process, you're knocking them out of a place where they really have a right as citizens and taxpayers to have a voice," he said.

Certain provisions in the new bill would effectively put the federal government in charge of overseeing transportation projects in rural areas. Marema said he believes it is vital for local officials to have input in those decisions. For instance, he said where a highway is located can decide whether business is brought to an area or taken away.