SR-57/SR-60 Confluence at Grand Avenue Project

Updated January 26, 2017


January 26, 2017 - Northbound Grand Avenue lanes will be closed for five nights from 7 p.m. to 6 a.m. for shoring operations.  This will create detours along Golden Springs Drive to either Diamond Bar Boulevard or Brea Canyon Road for freeway access.  City street signal timing within and surrounding the project area will be adjusted to accommodate the closure accordingly.

Also,the reduction of lanes in the northbound direction along Grand Avenue for the placement of temporary concrete traffic barriers.  This operation will narrow the roadway in the northbound direction from three lanes down to two lanes.

Additional traffic lane closures (see December 12 posting) will continue for approximately 9-12 months.

December 12, 2016 - DUE TO CONSTURCTION DELAYS, THESE TRAFFIC LANE CLOSURES HAVE BEEN RESCHEDULED TO MID JANUARY 2017. Caltrans will be restriping and reducing traffic lanes on Grand Avenue between Golden Springs Drive and Old Brea Canyon Road as part of the westbound off-ramp phase of the project. This phase of the project is expected to continue for approximately 9-12 months. 

  • Northbound:  Reduction of lanes to two through lanes north of EB on-ramp. Reduction of lanes to one dedicated through lane, one combined through-right turn lane and one dedicated left turn lane at WB on-ramp intersection.
  • Southbound: Reduction of lanes to one dedicated through lane and one combined through-left turn lane at the EB on-ramp. 

For questions, contact the City’s Public Works Department at 909.839.7040 or email at

About the project –

57/60 Confluence at Grand Avenue Project – The three phase project is designed to improve traffic operation on Grand Avenue from Golden Springs Drive to the interchange at SR-60 (Pomona), increase capacity at the Grand Avenue Interchange, improve traffic operation on the freeway mainline, reduce traffic weaving and increase weaving distance and improve safety.

Phase I -- Construction schedule: March 2016 - August 2017
Description: Construct the westbound Grand Avenue on-ramp and the westbound auxiliary lane on the SR-60.

Phase IIA -- Construction schedule: October 2016 - December 2017
Description: Construct improvements on the arterial highways, including Grand Avenue south of the SR-60 Interchange, approximately 0.4 miles of Golden Springs Drive, and rebuild the intersection of Grand Avenue and Golden Springs Drive.

Phase IIB -- Construction schedule: September 2016 - November 2017
Description: Construction of a westbound off-ramp and an auxiliary lane to Grand Avenue.

Phase III -- Construction schedule: September 2019 (estimated) - December 2022 (estimated)
Description: Construct Grand Avenue Bridge over SR-60, eastbound bypass off-ramp and eastbound bypass connector.


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