The Twin Cities freeway system saw a slight increase in traffic congestion from 2014 to 2015, according to the latest MnDOT Metropolitan Freeway System Congestion Report.

The report states the percentage of congested miles in the freeway system went up from 21.1 percent in 2014 to 23.4 percent in 2015.

The Regional Transportation Management Center (RMTC) evaluates 758 miles of the metro freeway system to create a percentage that combines a.m. and p.m. traffic. The RMTC tracks the percentage of miles where vehicles travel less than 45 mph. Officials measured traffic congestion through field observations and surveillance detectors in roadways. The testing is completed in the month of October as commuter flows are back to normal with school back in session and construction projects are mostly completed.