Nighttime closures Monday and Tuesday at the Karcher Interchange Bridge

Posted on by Jill Youmans
Aerial view of traffic traveling across a bridge on State Highway 55 in Nampa, passing under overhead signs for I-84 west to Caldwell and Ontario, Midland Boulevard north, and the Karcher Bypass.

The Idaho Transportation Department will close the Karcher Overpass Bridge on Monday, and Tuesday from 10 p.m. to 5 a.m each night. Crews will be removing the large steel structure that holds the signs over the bridge to make room for new signs that will support the new lane configuration.

Detours signs will be posted for drivers during the closures.

Motorists traveling south on Karcher Road (State Highway 55):

  1. Travel south on the Karcher Bypass.
  2. Turn right onto West Karcher Road.
  3. Turn left onto Midland Boulevard.
  4. Turn right onto Caldwell Boulevard.
  5. Continue straight to Karcher Road (SH-55).

Motorists traveling north on Karcher Road (SH-55):

  1. Use the eastbound on-ramp to merge on to Interstate-84.
  2. Exit I-84 at Northside Boulevard (Exit 35).
  3. Travel north on Northside Boulevard.
  4. Turn left onto Karcher Road/Karcher Bypass.
  5. Continue on Karcher Road/Karcher Bypass.

Click here to view the detour map.

The I-84, Karcher Interchange project will improve safety and mobility at the interchange and along Karcher Road in Nampa. Crews are expected to place final touches in late spring of 2026.

Stay informed by signing up for email and text alerts regarding project updates by texting 84CORRIDOR to 1-866-483-8422 or visit the project page at itdprojects.idaho.gov/pages/karcheric.