Traffic congestion drops 30% in 2011

The 2011 U.S. Traffic Scorecard indicates that traffic congestion was down 30% last year from 2010 in the nation’s 100 largest metropolitan areas. It marks the largest decrease since December 2007. Data from the study point to rising gas prices, stagnant employment growth and reduced construction as the major factors affecting traffic totals.

In total, 70 of the 100 metro areas saw congestion drop last year, leaving 30 where it rose. Minneapolis had the largest individual drop while traffic increased the most in Tampa.

Tampa was one of the cities with the greatest employment growth for the year at 3%. It was just one such example of the connection between job growth and rising congestion — Miami (2.3% employment growth) and Houston (3.2%) also sat in the top 10 metros with the greatest congestion increases.

On the other side, traffic congestion fell significantly in Minneapolis thanks to a decrease in road construction projects; 258 projects were undertaken in the area in 2011 compared to 283 in 2010.

The study was conducted by Kirkland, Wash.-based firm INRIX, which collected data from more than 100 million GPS-equipped vehicles and other sources.