U.S. Route 52 in Minnesota
U.S. Highway 52 (US 52 or Highway 52) enters the state of Minnesota at the unincorporated community of Prosper, north of the town of Burr Oak, Iowa. The route is marked north–south in Minnesota along its independent segment from the Iowa state line to downtown St. Paul. Highway 52 is not signed along the length of its concurrency with Interstate 94 (I-94) from downtown St. Paul to the North Dakota state line at Moorhead and Fargo. Route description. U.S. 52 enters Fillmore County and heads through the same Driftless Area it ran through in  Iowa. The route heads through Preston and proceeds north to Chatfield. Highway 52 leaves the river bluffs near Chatfield and enters terrain typical of southern Minnesota. This area is mostly farmland for the rest of the length until the route enters the city of Rochester. Highway 52 intersects Interstate 90 south of Rochester, and expands to a four-lane freeway north of this junction. The roadway expands further to six lanes around Rochester, from the junction with U.S. 63 to County Road 14, which is at the northern tip city. U.S. 14 is a major route, and connects Owatonna to  Rochester. North of Rochester, Highway 52 becomes a four-lane expressway through the farmland of Olmsted and Goodhue counties. Zumbrota is bypassed by the highway, and the route heads to Dakota County. In October 2014, an interchange was completed in Cannon Falls which eliminated the last two traffic lights between St. Paul and Rochester on Highway 52. North of Coates, Highway 52 enters the edge of the Twin Cities area. The route enters Inver Grove Heights where it becomes the "Lafayette Freeway" north of "Concord Boulevard". Highway 52 splits with State Highway 55 north of there. Highway 55 heads to  Minneapolis, while Highway 52 heads to St. Paul. Interstate 494 intersects 52 in the northern part of Inver Grove Heights. The St. Paul Downtown Airport is right off of Highway 52 in St. Paul. After Highway 52 crosses the Mississippi River in downtown St. Paul, the route intersects Interstate 94 and follows I-94 to the North Dakota state line; U.S. 52 is not signed along the length of this concurrency. History. U.S. Highway 52 was extended into the state of Minnesota in 1934. The road replaced the former routing of old U.S. Highway 55 from the Iowa state line to  the Twin Cities, and the former route of old U.S. Highway 10S from Minneapolis west to North Dakota. Interstate 94 replaced most of the routing of Highway 52 west of St. Cloud, and the routing from St. Cloud to Minneapolis was replaced by U.S. Highway 10, U.S. Highway 169, and Hennepin County Road 81. Highway 52 was routed along "University Avenue" through Minneapolis and St. Paul until about 1995 (In 1986, Highway 52 on "University Avenue" between I-35W and the St. Paul border was turned over to Hennepin County maintenance and renumbered "County 36 / 37", creating a gap in Highway  52 until the 1995 route change). West of here, it turned west onto Washington Avenue that traversed directly through the University of Minnesota and Downtown Minneapolis. Progressing further, it took another left turn at Broadway Street before eventually curving to the northwest towards Robbinsdale, Crystal, Brooklyn Park and Osseo. Afterwards, it turned right onto what is now US Highway 169 through Champlin and Anoka thus eventually merging onto US Highway 10 towards Elk River and St. Cloud. It eventually turned onto city streets through St. Cloud and back onto the present-day Interstate 94 alignment. 52 was routed along "Robert  Street" through St. Paul, West St. Paul, and into Inver Grove Heights until 1995; when 52 was moved onto the nearby "Lafayette Freeway". The Lafayette Bridge which takes the highway across the Mississippi River near downtown St. Paul was originally built in 1968 and was a "fracture critical" structure which was in need of replacement. Construction of the new bridge, which carries six lanes of US-52, was completed in fall of 2015. U.S. Highway 52 was built as an expressway from Rochester to St. Paul in the 1960s. The "ROC52" project expanded the section of Highway 52 in Rochester to  a 6-lane freeway in 2005–2006. Between Rochester and the Twin Cities, several at-grade intersections have been converted to interchanges since the 1990s. However, many at-grade intersections remain along this segment of highway. An experimental installation of Cooperative Intersection Collision Avoidance Systems–Stop Sign Assist (CICAS–SSA) was installed at the at-grade intersection with Goodhue County Road 9 near Cannon Falls, making use of dynamic message signs to show when it is safe to cross or turn onto the highway. A full-scale field test began in January 2010, though a previous version had also been tried  at the intersection a few years earlier. This intersection was later converted to a full grade-separated interchange, with the work completed in late 2014.