Unstable Slope Management for Oregon Highways: Using Cost-Based Risk Assessment in Conjunction with Site Characteristics to Manage Landslide and Rockfall Effects on the Transportation System

Curran Mohney, C.E.G.Engineering Geology Program LeaderOregon Department of Transportation

Current Funding VS Repair Cost of the 500 Highest-Ranked Sites

$0

$500,000,000

$1,000,000,000

$1,500,000,000

$2,000,000,000

$2,500,000,000

$3,000,000,000

$3,500,000,000

6/30/1998 6/30/2003 6/29/2008 6/29/2013 6/30/2018 6/30/2023 6/29/2028 6/29/2033 6/30/2038 6/30/2043 6/29/2048

Current Funding

Outstanding Repair Cost

Program Goals:

• Locate and Rank all Unstable Slopes affecting the State’s Highways

• Prioritize and Select Projects

• Allocate Funds

• Provide Information to Policy and Decision-Makers

• Integrate Data and Analyses with Internal Disciplines and other Agencies

Program Criteria:Program Criteria:

● Manage All Unstable Slopes Uniformly

● Manage Risk and Liability Uniformly

● Scale Higher-Order Analyses Relative to Site Priority

● Utilize An Impact-Based System

● Rank and Prioritize Landslides and Rockfalls in Accordance with the Federal Highway Administration’s Asset Management Concept

Asset Management:Asset Management:• http://www.fhwa.dot.gov/infrastructure/asstmgmt/ind

ex.htm

• Decision-Making Methodology

• Draws from Business and Economics

• Supplements Scientific and Engineering Analyses

• Supports Decision-Making– Evaluate Trade-Offs– Conduct “What-If” Analyses– Make Sound “Investment” Decisions

Unstable Slope Rating System:Unstable Slope Rating System:

Hazard ScoreX

Maintenance Benefit-Cost FactorX

Highway Classification Factor=

Final STIP Score

Unstable Slope Data Collection Unstable Slope Data Collection Procedures:Procedures:

Unstable Slope Unstable Slope ManagementManagement

Locate, Rank, Prioritize, and Select Sites for Repair

Perform Analyses: Cost-Benefit, Life Cycle Cost, etc.

Provide Information to Regions, Districts, Other Agencies, Public, etc.

Unstable Slope Risk ManagementUnstable Slope Risk Management

Questions ?Questions ?