Updated at 3:01 p.m. on July 13.
The threat of climate change, the need for new energy sources, and the changing needs of a growing population demand that we not simply expand, but also modernize, our transportation system to meet the challenges of the 21st century. Our nation's roads, rails, airports, waterways and ports will continue to be a foundation of our economy, but they will almost certainly have to function differently. How can we update our national transportation policies to encourage greater economic growth and competitiveness in the global economy while accomplishing the equally important goals of reducing greenhouse gas emissions and congestion, increasing mobility and improving the safety our of transportation system?
Editor's note: To bring additional perspectives to the debate, we have invited business leaders who are in Washington, D.C., July 14-15 for the U.S. Chamber of Commerce's "Transportation Is Your Business" event to join this week's conversation.