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ODOT is working to reduce the impact of US 101 closures from landslides on the southern Oregon coast

In this online open house, you can learn more about the study, the areas impacted, the potential tools and solutions, and the ways in which you can participate.

Select a station below or click "Next" to move through the open house in order.


Learn about the purpose of the study.
Learn about alternative routes and strategies for responding to closures on US 101.
Review what we know about landslides and alternative routes and give us feedback.
Learn what comes next and how to stay informed about the study.


We are currently studying different concepts for improving transportation resiliency along US 101 between Port Orford and Brookings.

Project Area

Project area showing south coast slide locations along US 101. (Click to enlarge.)

An ongoing challenge

US 101 is the primary north-south transportation corridor along the Oregon coast and it is the economic lifeline for the area. Landslides and road failures in this area have been a problem for decades, resulting in road closures that take days or weeks of work to fully reopen to traffic. When US 101 is closed, travelers rely on detours via Interstate 5, OR 42, or US 199.

When there is a landslide the damage is costly to fix, disrupts freight movement, strains emergency service providers, and prevents coastal residents from reaching critical services. Landslides also disrupt tourism, which is an important part of the economy in Oregon’s coastal communities and surrounding areas.

Buckled road from landslide damage. Erosion and slope failures are common and natural along this section of the coast.
Erosion and slope failures are common and natural along this section of the coast. (Click to enlarge.)

Study purpose

The goal of this project is to improve transportation resiliency along US 101 between the cities of Port Orford and Brookings. The study will identify practical and cost-effective solutions to reduce the impacts of study landslides while improving how quickly the transportation system can recover after landslides occur.

Study goals

  • Identify strategies to stop and/or reduce the recurrence of the study landslides
  • Reduce recovery times
  • Improve traffic control and communications
  • Improve safety and operations along US 101 and other viable detour routes during an event
  • Reduce operations and maintenance costs

Key tasks

  • Evaluate and prioritize which of the study slides are most likely to result in a partial or full closure
  • Evaluate potential routes around slides
  • Develop conceptual mitigation strategies with cost estimates for roads and slides
  • Work with stakeholders to identify transportation challenges during slides
  • Develop traffic control plans for slide events
  • Document all information in one place

40% Complete

Tools and Solutions

Over the years, ODOT and local jurisdictions in the region have evaluated ways to reduce the impacts of slides and improve US 101 and detour routes to facilitate travel in the event of a partial or full closure of US 101.


All alternatives to improve slide conditions and roadways are limited for three key reasons:

  • Risk of making an existing slide more unstable through construction activities
  • Steep topography on one side of US 101 and the ocean on the other
  • A high number of other active slides in the study area

(See the next page for more information about alternative routes.)

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  • Slide Mitigation

    Slide Mitigation

    Slide Mitigation can help reduce the frequency of landslides. Common reasons for the 13 slides along US 101 are shallow groundwater within the slide area, coastal erosion, or a combination of both. Solutions will reduce the frequency of roadway maintenance and lane closures due to landslide movement.

    • Shear Keys act as a pin to hold layers of soil together and make it harder for the landslide to move. Shear keys are created using stone columns, shear piles drilled shafts, or excavation backfilled with stone

    • Soldier Pile Tieback Walls act as walls to hold landslides back

    • Drains (horizontal or trench) remove water from the slide to make the soil in the landslide more stable

    • Stockpiling means storing materials such as gravel nearby to make it easier to rebuild the roadway after a landslide occurs

  • Alternative Routes

    Alternative Routes

    There are very few routes around slide areas and many of the potential routes are also impacted by the study landslides, have steep terrain, or are constrained by streams or other  factors that would restrict freight and passenger travel. Two alternative routes were identified as feasible:

    Carpenterville Highway is the only route that bypasses the slides near Hooskanaden and has been used as public detour route in the past. It has restrictions for loads that are overweight, over width, or long. Historically, pilot cars have been used to allow larger freight vehicles to navigate the corridor.

    Elk River Road/FS-5502/Euchre Creek Road is identified as a restricted access route, intended only for ODOT maintenance and emergency vehicles. It bypasses the landslides around Humbug Mountain. The route follows a combination of paved county roads, paved local roads, and Forest Service gravel roads.

  • Roadway Mitigation

    Roadway Mitigation

    Roadway mitigation can allow roadways to function more safely and efficiently during closures. Mitigation might include:

    US 101. In general, improvements to US 101 are limited due to environmental considerations, topography and the risk of widening activities creating new landslides or activating existing landslides. Additional gravel stockpile locations could be provided along US 101 so ODOT could respond more quickly to landslides.

    Carpenterville Highway. There are approximately 100 landslide locations along Carpenterville Highway, which limits opportunities to widen roads or address sharp curves.  Isolated areas have been identified for potential shoulder widening and gravel stockpile locations.  Additionally, the travel experience could be improved by adding destination and directional signage. 

    Elk River Road/FS-5502/Euchre Creek Road is intended only for ODOT maintenance and emergency vehicles. The gravel northern portion of the route is extremely steep, based on field observations. Paving this northern section of the route may increase traction and comfortability of the road.

  • Traffic Control and Communication

    Traffic Control and Communication

    Traffic control and communication strategies can increase safety and travel efficiency during landslide events, while minimizing the inconvenience of detours. Traffic control and communication strategies can allow travelers to navigate sections of highway that are partially closed, or allow large vehicles to navigate sharp turns or narrow detours. Strategies will include:

    • Develop plans for temporary road signs and devices to alert and guide traffic

    • Develop communication strategies and clarify roles and responsibilities

60% Complete

Landslide Areas Map

Below is a map of the study area that shows the locations of landslides and evaluated routes. Click on map elements to learn more and answer the questions to give us feedback.

Landslides Map


Please submit your responses before moving to the next page.

80% Complete

Next Steps

Thank you for your feedback. We will use your input to refine our understanding of possible tools and mitigation strategies as we develop traffic control plans and landslide management strategies.


  • Stakeholder Outreach. Summer 2022 (Small group interviews and presentations)
  • Traffic Control Plans. November 2022
  • South Coast Slide Management Study. Spring 2023

For more information

100% Complete