Project Location

US 51, Reardon Road to just north of County V (Grinde Road), Windsor to DeForest, in Dane County.

Project Overview

  • Reconstruct this segment of US 51 into a 4-lane divided highway.
  • Existing two lanes will be reconstructed and an additional two lanes added to create a 4-lane divided highway.
  • The new 4-lane divided highway will transition back to two lanes just north of County V (Grinde Road).
  • Interchanges to be constructed at Windsor Road and County V / North Street.
  • Because US 51 is designed to freeway standards, all access to the highway outside of the interchanges will be removed.
  • Current private driveway accesses onto US 51 will be relocated to existing side roads, new frontage roads or new development streets.
  • County V will be realigned east of US 51.
  • There will also be bridges constructed as overpasses of two side roads, Vinburn Road and the proposed Bear Tree Parkway.

Proposed traffic staging

Construction scheduled in two phases:

  • Staging 2013-2014 - Phase 2 construction, Vinburn Road to County V (Grinde Road); construction currently in progress.
  • Staging 2012-2013 - Phase 1 construction, Reardon Road to Vinburn Road; construction complete.

Roadway changes


US 51, from just north of WIS 19 interchange to Grinde Road, will be expanded from a 2-lane highway to a 4-lane highway.

Access to US 51 will only be allowed at interchanges. Two full diamond interchanges located at Windsor Road and North Street / County V are included in the proposed design.

Other features of design are identified below and can be seen on the proposed changes map above:

  • The proposed design will utilize the existing US 51 roadway on the north and south end as one roadway while an additional 2-lane roadway will be constructed along side.
  • From Windsor Road to County V / North Street, all 4 lanes will be constructed east of existing US 51 and existing US 51 will be converted to a frontage road called North Towne Road. All driveways and side road access points on the west side of existing US 51 will maintain access to North Towne Road.
  • Roundabouts will be constructed at the ramp terminals of the Windsor Road and County V / North Street interchanges, as well as on the north and south ends of proposed North Towne Road.
  • County V will be realigned east of US 51 between North Street and County V (east).
  • Overpass structures will be constructed at proposed Bear Tree Parkway and Vinburn Road. Side roads that currently intersect US 51 that will not have overpasses constructed, will become cul-de-sacs. These side roads are Reardon Road, Gray Road (west), Grinde Road and Windsor Way.


Project location

View US 51 Expansion project in a larger map.

Map key - Thick orange line is the project overview/location, yellow line is detour route, and the blue tear drop with dot in center are the project limits.

Camera images

WisDOT camera located at US 51/WIS 19, view NE.

US 51/WIS 19 camera image.