WIS 57 then transitions into an expressway, passing by Fredonia, Random Lake, Adell, and Waldo in Ozaukee and Sheboygan Counties.

While in Chilton, the two routes connect with U.S. 151 which the latter provides access towards Manitowoc and Sturgeon Bay along the scenic Schooner Coast.

WIS 32/57 enters De Pere from the south and crosses over an incomplete interchange with County Highway PP and regaining two lanes in each direction.

WIS 42/WIS 57 intersects with CTH-C and CTH-S before crossing over the business routes at an incomplete interchange.

WIS 57 ends at the parent route at another recently constructed roundabout, and the road narrows back down to one primary lane in each direction for the last time.

Before entering Jacksonport, WIS 57 passes through the twin unincorporated communities of Institute and Valmy.

It was extended northward from Milwaukee to Green Bay along what is generally its present-day route and southward from Racine to the Illinois state line.

The state wanted an Interstate to connect Milwaukee and Green Bay, two of Wisconsin's largest cities.

Their plan chose the WIS 57 route over the nearby US 41 and US 141 corridors; the state did not want the Interstate's route to favor either the port cities of Manitowoc and Sheboygan or the inland cities of Appleton, Fond du Lac and Oshkosh.

[1] The US 41 corridor eventually became I-41 in 2015, providing Interstate access to all the cities the WIS 57 routing would not have favored.

WisDOT rerouted WIS 57 in south Ozaukee County during the early 1990s in response to local municipalities who complained about heavy traffic on the road.

This realignment signed the highway along WIS 167 and I-43 to avoid entering the downtown areas of Mequon, Thiensville, Grafton and Cedarburg.

[7] This section had been a two-lane highway, but traffic during the vacation season caused long delays and made an expansion necessary.

[8] The heavy traffic also resulted in the deaths of eighteen people on this section between 1994 and 1997, earning the highway the nickname "Bloody Route 57" among locals.

[8] The results of extensive archeological excavations made in connection with the project are detailed along with a discussion of the highway expansion in informational kiosks at the CTH-C park and ride lot in Door County and at Wequiock Falls in Brown County.

[12] WisDOT then began Phase 3 of the project, which widened the rest of the highway through the WIS 42 junction.

The first part of this phase, a 6-mile (9.7 km) bypass of Dyckesville that reached the Door-Kewaunee county line, opened on December 1, 2006.

[13] The entire project was completed on October 6, 2008, when the last 11-mile (18 km) section near Sturgeon Bay was officially opened.

[20] It was again closed to all traffic when the Maple and Oregon Streets Bridge opened in September 2008, and Bus.