2012 Metro Freeway Congestion. Source: Metro Freeway System 2012 Congestion Report
MnDOT publishes an annual congestion report, showing congestion on freeways in the greater Twin Cities area. MnDOT defines congestion as segments where speeds are below 45 MPH.
N.B. The proximate supply-side cause of the congestion may be downstream bottlenecks, so this map is reflecting the effect, not necessarily the cause. The demand-side cause of the congestion is more vehicles than the supply can accommodate in a given time.