The United States cannot solve its traffic congestion problem without expanding its highway system, says the American Association of State Highway and Transportation Officials in a new report titled "Unlocking Gridlock."

"We're hearing at the policy level in Washington, D.C., voices saying you can't build your way out of congestion, we have built enough roads. That's not true," said John Horsley, executive director of AASHTO, at the introduction of the report yesterday.

The report says that transport needs, particularly in urban areas, is being driven largely by population growth. The U.S. population is expected to grow by 27 million people in the next decade - almost 9 percent. Over the next 40 years, growth will range up to 36 percent.

AASHTO supports increased investment in transit, intercity passenger rail, bike lanes and pedestrian paths, but highways are essential, Horsley said. "Expanding highway capacity is not the only thing that will be required to meet future mobility needs, but it will be a principal part of what will be required."

The Interstate Highway System is key, AASHTO says. It represents just 1 percent of total highway miles but carries 24 percent of all traffic and 41 percent of all combination-vehicle truck traffic. The group is calling for addition of 30,000 lane-miles to the current 85,000 lane-mile Interstate System, and of 40,000 lane-miles to urban segments of the National Highway System.
This report focuses on urban transportation needs, but AASHTO intends to soon publish similar reports on rural and freight needs, Horsley said.

At this time the money needed for transport infrastructure is not there. Congress is working on legislation to reauthorize the federal highway program but there is little appetite on Capitol Hill to address the key issue of raising funds through a fuel tax increase.

Horsley said the current program has enough money to get through this fiscal year and possibly next, but then the outlook becomes bleak. "Unless new revenue sufficient to sustain the program is generated from some source, the highway program would have to be cut from $43 billion down to $21 billion in October 2011," he said.