skip to main content
Idaho Official Government Website Contact Us

SH-55, Smiths Ferry Improvements

In fall 2020, ITD started construction on this project to widen the highway, straighten the road alignment, and add guard rail along a curvy one-mile stretch of State Highway 55 between Smiths Ferry and the Rainbow Bridge. These important safety improvements are now finished.

WINTER 2022/2023 SCHEDULE
Construction work has now paused for the winter season and both lanes are open for travel. Slope finishing work will resume this spring.

WHAT TO EXPECT:

Winter (beginning November 15)
– No construction will take place.
– The project site will be closely monitored with the snowpack, temperature, and forecast checked regularly. If potential avalanche conditions based on these measurements are identified this winter, the road may be temporarily closed and drivers will be asked to use U.S. Highway 95 as an alternate route until the area is cleared. Be prepared and check 511.idaho.gov before traveling.

Spring 2023
– Slope finishing work will continue this spring and includes implementing avalanche mitigation snow fencing systems that are designed to minimize future risk.
– Temporary single lane closures are possible and will be announced if needed.

September 2020
Construction starts with full road closures Monday - Thursday, 10 a.m. - 2 p.m.
November 2020
Construction suspended for winter season, all lanes are open
March 2021
Work resumes with full road closures Monday - Thursday, 10 a.m. - 2 p.m.
June 2021
Summer work schedule starts
September 2021
Full road closures begin Monday - Thursday, 10 a.m. - 2 p.m.
December 2021
Construction suspended for winter season, all lanes are open
March 2022
Spring construction starts
May 2022
Summer work schedule starts
September 2022
Work adjusts to fall schedule
November 2022
Paving complete, work pauses for winter
FAQ
What is the designated detour to avoid construction?
What is the designated detour to avoid construction?

Drivers are encouraged to use U.S. Highway 95 during construction to avoid full road closures and travel delays.

Why can't SH-55 have two travel lanes to accommodate weekend traffic in the fall and spring?
Why can't SH-55 have two travel lanes to accommodate weekend traffic in the fall and spring?

The contractor has brought in large steel containers and one-way barriers to prevent falling rock from entering the travel lane, and protect the crews working next to live traffic. It is not feasible to remove this set-up each weekend. Also, the contractor will be working as much as possible in the spring and fall to complete the work. This approach better accommodates heavy weekend travel in the summer.

Why is this project needed?
Why is this project needed?

This segment of SH-55 sees a crash rate that is higher than normal. Many of the crashes involve speed or loss of control with no opportunity to correct because of the narrow, winding road.

How long will it take to complete these improvements?
How long will it take to complete these improvements?

The project is expected to be complete by summer 2023.

What if emergency vehicles need to get through the work zone or road closure?
What if emergency vehicles need to get through the work zone or road closure?

The project team is coordinating closely with local emergency service providers and first responders to ensure safe passage through the work zone as needed. Dispatch has direct contact with onsite staff to coordinate access.

Can Smiths Ferry Drive be used to bypass the project?
Can Smiths Ferry Drive be used to bypass the project?

Smiths Ferry Drive will be closed to through traffic but will remain accessible to local residents and property owners.

What is the speed limit in the work zone?
What is the speed limit in the work zone?

25 mph

Will the Payette River remain open to recreation users during construction?
Will the Payette River remain open to recreation users during construction?

The river will be open through the remainder of construction.

Where can I find the most up-to-date information?
Where can I find the most up-to-date information?

Sign up for email updates, which will be distributed regularly to provide information about the project. Drivers can also download the 511 app or visit 511.idaho.gov for travel information.

Is ITD constructing a bypass from Smiths Ferry to Round Valley?
Is ITD constructing a bypass from Smiths Ferry to Round Valley?

No. ITD has evaluated several alternatives over the past 20 years in order to improve safety and mobility on this stretch of SH-55, including this current project and a bypass. This project is more cost-effective and has fewer environmental impacts than the bypass.

Will the project improve or replace Rainbow Bridge?
Will the project improve or replace Rainbow Bridge?

No. The current project will not make any changes to Rainbow Bridge. ITD is working on a long-term plan to replace Rainbow Bridge that will increase mobility while preserving the historical bridge.

Is there a width and/or length limit in effect for commercial vehicles?
Is there a width and/or length limit in effect for commercial vehicles?
Loads allowed: a single trailer may not exceed 48 ft, and a double-trailer configuration may not exceed 61 ft. Overall length may not exceed 75 ft. An extra length permit is required if exceeding these dimensions.

Any vehicles or loads above these restrictions are not allowed on SH-55 or through the work zone. 

Will my trailer fit through the work zone?
Will my trailer fit through the work zone?

ITD does not allow trailers longer than 48 feet or trucks with trailers longer than 75 feet to travel on SH-55 without a permit. Vehicles and loads are restricted to 11 feet wide, 75 feet long, and must adhere to the 25-mph work zone speed limit. To get a permit, visit trucking.idaho.gov/permits/.

Will the work zone affect my current oversize load permit for SH-55?
Will the work zone affect my current oversize load permit for SH-55?

The work zone follows the same restrictions in place for traveling on SH-55. For more information on permits, visit trucking.idaho.gov/permits/.

© Copyright 2022 Idaho Transportation Department Visit ITD Website

Contact the Project Team

Default Project Comment Form
Maximum upload size: 8MB
Maximum upload size: 52.43MB