Road traffic congestion costs the trucking industry an estimated $27 billion a year because of lost time and extra fuel consumption, the Department of Transportation said yesterday in releasing its National Freight Strategic Plan.

The shipping delays caused by congested roads and highways add billions of dollars in costs by raising prices on a massive array of products, DOT said. The agency did not quantify the costs to consumers arising from congestion-related delays.

All told, the annual cost of congestion, including passenger-car delays on roads shared with trucks, is estimated at $1 trillion, or roughly seven percent of U.S. economic output, DOT said.

In 2011, increases in truck and passenger-vehicle traffic regularly impacted 10 percent of the 161,000-mile National Highway System, which includes the 47,000-mile Interstate Highway System, the DOT report said. By 2040, that figure will rise to 34 percent of the national system unless steps are taken to reverse the trend, according to the report.

Currently, about 13,500 miles of highway system regularly slow below the posted speed limits, and an additional 8,700 miles experience stop-and-go conditions, the report said. The report called for the implementation of more and better transit options, greater intermodal connectivity, and more deployment of information technologies to help resolve the congestion problem.

The 143-page draft report shed some economic light on the congestion issue, something that has long proved elusive. Few would deny, however, that it is a problem. For example, Bill Matheson, president of intermodal and logistics services for Schneider National Inc., the Green Bay, Wis.-based truckload and logistics giant, said in a recent e-mail that congestion in the Chicago market results in a 5- to 10-percent reduction in the company's drayage productivity, relative to other U.S. markets. In the report, DOT called for a dedicated funding mechanism exclusively for freight projects, an initiative that's been part of proposed Congressional legislation to fund the federal transport system for a multiyear period.

DOT has made available a page on its web site for public comment on the draft. The URL is www.transportation.gov/freight/share-your-ideas.