writes "Math watch time: For many traffic analysts, INRIX is considered the gold-standard. This week the company says traffic congestion surged in 2013 and grew over three times as fast as the American economy. The bad news: If true, this reverses two consecutive years of traffic declines with a six percent increase in 2013. (GDP, by comparison, grew 1.9 percent last year.) The analysts then theorize links between economic growth and traffic congestion, which makes sense on the surface. (As the economy improves, more jobs are created, so more commuters on the roads) But INRIX's theory creates as many questions as it answers. For example, the U.S. GDP has been steadily growing since 2009. So why did congestion decline in 2011 and 2012?"