Overview
The work is necessary to keep the bridge safe for all traffic. It will eliminate the need to implement load restrictions that could impact service vehicles, delivery vehicles, and cattle trucks using SH-55.
Maintenance will allow the Rainbow Bridge to serve the community until a new bridge is constructed in 2029. Work will include:
- Repairing reinforced concrete bridge elements.
- Replacing expansion joints.
- Repairing deck surface.
ITD has completed maintenance work on the Rainbow Bridge. All lanes of the Rainbow Bridge are now open. This work will keep the bridge operating safely until a new bridge is constructed in 2028. Thank you for your patience throughout this project!
Traffic Impacts
Work began in May and will continue until fall 2025. This spring and summer, motorists can expect:
- Lane closures and temporary traffic signals Monday-Thursday. One 11-foot lane will be open.
- No anticipated traffic impacts Friday-Sunday.
- No anticipated traffic impacts on major holidays (such as Memorial Day, 4th of July, and Labor Day).
- Lanes will be reduced to 11 feet wide.
Timeline
Work will end this fall.
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Winter 2025
Design plans complete.
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May 2025
Construction begins.
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Fall 2025
Project anticipated to end.
Frequently Asked Questions
- Upstream of the bridge
- The boat launch area at Cabarton Road Bridge
- Downstream raft take out locations in Smiths Ferry
Due to Rainbow Bridge’s age and condition, it is inspected more frequently than ITD’s standard two-year bridge inspection cycle. The bridge is inspected every 12 months by one of ITD’s certified bridge inspection teams. It was last inspected in April of 2024. ITD follows a specific bridge inspection process based on federal standards. For more information about ITD’s bridge program, visit itd.idaho.gov/bridge/.
- Repairing the bridge deck.
- Repairing drainage issues.
- Replacing an expansion joint.
- Repairing concrete on the substructure (below) and superstructure (above).
- Replacing the bridge railing.
Contact the project team
Contact the project team at 208-391-6580 or sign up for updates.
For information about traffic conditions, please visit: 511.idaho.gov.