Construction season is kicking off on State Highway 55, a vital link in the north-south corridor connecting Boise and Lewiston. With Idaho’s short summer construction window and the need for warm temperatures before snowfall returns, the Idaho Transportation Department will soon begin several key projects along SH-55 to maintain and improve this critical route as shown on the attached map.
Motorists should expect significant delays and are encouraged to travel during off-peak hours—such as early mornings or late evenings. ITD recognizes the inconvenience construction may cause, but each project is part of the department’s continued commitment to enhance safety and mobility along this essential route. From bridge replacements to essential maintenance, these efforts are designed to keep Idahoans moving safely and efficiently throughout the region for many years ahead.
North on the map from Eagle to New Meadows, drivers can expect the following projects this construction season:
Horseshoe Bend to Boise National Forest Boundary Chip Seal (Construction: summer 2025) ITD will apply a chip seal to SH-55 between Horseshoe Bend and the Boise National Forest Boundary to extend the life of the pavement. The highway will be reduced to one lane with pilot cars where crews are working. Work hours are 6 a.m. to 9 p.m. Monday-Thursday, and 6 a.m. to 12 p.m. on Friday from mid-June to mid-August.
Fleming Creek Bridge Replacement (Construction: fall 2024 – late 2025) ITD is replacing the Fleming Creek Bridge on SH-55 approximately four miles south of Banks. The project includes a minor realignment of SH-55 to accommodate the bridge and meet current standards for roadway geometry. Work this year will have minor impacts to motorists.
Banks-Lowman Road Intersection Interim Traffic Signal (Construction: spring 2025) The new signal was activated May 5 and replaces flagging operations that had previously occurred during peak travel periods, providing a safer and more efficient solution for travelers. Travelers may expect delays around the signal.
Rainbow Bridge Maintenance (Construction: spring – fall 2025) ITD will repair concrete bridge elements, replace expansion joints and repair the deck surface. This maintenance is necessary to continue meeting safety and capacity standards until a new bridge is constructed in the future. During the week (Monday-Thursday) one lane of traffic will be open across the bridge. On weekends (Friday-Sunday), both lanes will be open. Prior to Memorial Day, one-lane closures may occur on weekends.
Dynamic Message Sign (Construction: summer 2025) ITD is installing a dynamic message sign on SH-55 this summer between Round Valley and Cascade. The new message board will notify motorists of detours or incidents.
Little Goose Creek Bridge (Construction: June 2024 – fall 2025) ITD is replacing the Little Goose Creek Bridge along SH-55 near New Meadows. This project has been extended due to weather, road conditions and unexpected contractor delays. SH-55 will continue to be reduced to one lane with a traffic signal during construction. Work will be completed this fall.
Motorists are encouraged to check 511.idaho.gov before traveling throughout the state for the latest road conditions and construction updates. However, due to limited cell phone reception along parts of the SH-55 corridor, real-time delays may not always be accurately reflected. Drivers should plan for significant weekend delays and allow extra time for travel.