DULUTH, MN (KDAL) - Concrete grinding work begins Monday (9/28) in the I-35 tunnels in Duluth. The Minnesota Department of Transportation (MnDOT) says motorists can expect intermittent single lane traffic in the tunnels during work hours through October 8th. As part of the work, a full day long closure of the northbound on ramp and southbound off ramp at Lake Avenue is expected to take place mid week. Motorists are asked to be patient and expect delays and traffic backups during peak travel t...