This chart (or should we say charts) from the Inrix Scorecard shows the diurnal, weekly, monthly, and trend levels from INRIX. There is more congestion in the morning and especially the evening. Thursday evening gets more traffic than any other day, though Friday afternoon is higher, and Tuesday wins the morning. It’s all very proprietary, but traffic congestion overall seems to be hovering pretty constant between 2010 and 2013.
At any rate, Minneapolis comes in at 16th (Yay, we have traffic, we are not dying [like some other Midwestern cities we could name]) (Boo, we have traffic), which is not surprising given it is arguably the 13th largest metro area in the US (it all depends on definitions).