Culvert Inspection to Asset Management: Climate-Change Informed Capital Works Program for Alaska Highway

ABSTRACT
The paper outlines a comprehensive approach utilizing culvert inventory and condition data
collected based on the AASHTO Culvert and Storm Drain System Inspection Guide (2020) to
develop a condition, and climate-informed risk-based twenty-year capital works program for 2,200
culverts on Alaska Highway. The paper goes on to explain the methodology for establishing
monetized life-cycle failure risks stemming from condition deterioration and extreme climate
events. The life-cycle risk assessment is used to develop a culvert asset management system,
which is used to produce a multi-year climate-informed capital works program.

In a previous study, a climate change vulnerability and risk assessment were completed on
selected critical culverts on the highway using inventory and limited condition data collected 10
years earlier. As an outcome of this previous study, a comprehensive culvert inspection was
carried out in 2022 based on the more robust data collection criteria outlined in the Culvert and
Storm Drain System Inspection Manual (AASHTO, 2020). This 2020 AASHTO Inspection Manual,
updates the inspection and rating criteria, incorporating over 30 years of changes since its original
publication in 1986. The previous study's approach to assessing the risks posed by condition
deterioration and climate change to 2,200 culverts along the Alaska Highway, British Columbia,
was improved with more accurate culvert components-based predictive models to develop a
capital works program to address those risks in terms of replacement, adaptation, and
maintenance.

The adaptation and/or replacement options, (strategies), were evaluated in a Life Cycle Cost
Analysis (LCCA), by monetizing the costs and benefits of multiple strategies over a 60-year
period. The economic analysis for climate change adaptation options quantifies the extent of cost
and benefit of adaptation options under climate change scenarios. The costs considered in the
LCCA include both "direct costs," directly incurred by the asset owners, and "user costs," which
road users would incur through delays and detours. Overall, this approach should ensure that the
culverts along the Alaska Highway can withstand the impacts of climate change and remain
functional over the next 20 years.

Keywords: Culvert Inventory and Condition Inspection, Culvert Asset Management,
Transportation Asset Management, Climate Change Adaptation, Climate Vulnerability, Risk-
Based Asset Management, Sustainability and Resilience, Transportation Systems Resilience,
Risk and Resilience Management, Natural Hazards and Extreme Weather Events, Climate
Change, Vulnerability and Resilience Assessment, Hazard Mitigation