US traffic congestion varied in line with regional economic developments (Photo: Inrix)

US traffic congestion jumped a sharp 9.4 pc in April from a year earlier, but traffic intensity varied widely from one region to the next, according to the Inrix Gridlock Index (IGI).

The indicatormeasures congestion on the basis of a historical traffic information database comprised by Inrix, a US-based traffic data specialist.

Inrix said the overall increase in the IGI reflected an uppick in economic activity. "The latest IGI shows the US economy is getting back to business," Inrix CEO Bryan Mistele said in a press release. The data gatherers noted congestion shot up in midwestern urban areas, where the economy is doing better, while the southern US, with less economic improvement in evidence, lagged behind.

The data showed that the average trip in the 100 most populated metropolitan areas in the US took nearly 7 pc longer than a year earlier as a result of traffic congestion. In big midwestern cities congestion shot up 14 pc, while in Northeastern cities it was 10 pc higher than a year earlier. On the other end of the scale, Baton Rouge in the south witnessed a 38 pc decline in congestion, while in New Orleans congestion dropped 21 pc.

Said Mistele: "The pattern we're seeing in our data shows that the economies in some regions like the Midwest are accelerating while others are stuck in lower gear."