A new report says gridlock in the U.S. has staged a dramatic comeback after two years of post-recession lows, but it’s also a sign the economy is bouncing back.

Data from the most recent Inrix Gridlock Index shows traffic jumped by almost 10% during February – the largest year-over-year increase recorded in two years, and a healthy sign of rising economic activity across 100 metro areas.

"Traffic is a great indicator of confidence on the ground," says Bryan Mistele, CEO of Inrix, which provides traffic data and analytics. "People hit the road as they return to work, and businesses ship more freight as their orders increase. IGI shows the pulse of the economy is starting to beat faster."

Inrix says February's composite IGI score of 6.8 meant that the average trip took drivers in the 100 most populated metro areas 6.8% longer because of increased traffic congestion.

The dramatic shift seen in the top-line trend was mirrored by significant jumps in traffic congestion in many of the nation's largest metro areas. For example, gridlock in Chicago increased over 20% from February 2012 to this past February. In Phoenix it moved almost 19% higher while New York it jumped almost 18%. Inrix pointed to various positive economic reports about the three areas as indications business conditions are improving along with traffic congestion increasing.

Bucking these trends were San Antonio and San Diego. Inrix says these metro areas saw traffic decrease by 24% and 18%, respectively, providing an indication of the impact defense spending cuts that went into effect in March could have on the local economy.

Inrix drew its conclusions by also using its historical traffic information database made up of data collected from hundreds of public and private sources, including a crowd-sourced network of vehicles and mobile devices on the road.