Extreme weather events are becoming a more realistic possibility each year and cities need to start preparing aging infrastructure for this likelihood
By Ehsan N. Minaie, Ph.D., PE & Lauren M. Miller
Extreme weather events have recently caused massive destruction to communities and our transportation infrastructure, propelling resilency to the forefront of the national conversation. Lack of infrastructure resilience can affect multiple aspects of a city, including emergency response, the economy, trade, and the general well-being of residents. Regional and municipal infrastructure stakeholders and owners face many challenges in managing their assets. To prepare for the increasing likelihood of extreme events, agencies can apply proven strategies to help improve infrastructure resilience. By applying a structured approach to resilience planning, cities can strengthen their networks, allowing for life and businesses to carry on with less interruption and increased reliability during and after extreme events.
Vulnerable, Aging Transportation Infrastructure Coupled with Increasing Demand and Dwindling Funds
The U.S. transportation network of highways, roads, bridges, and tunnels is one of the largest and oldest in the world. U.S. infrastructure is in poor condition, garnering a D grade for roads and a C+ for bridges, according to the American Society of Civil Engineers 2017 Infrastructure Report Card. The report card shows that gaps in funding to maintain or improve the surface transportation network’s condition are increasing, with estimated shortfalls of $1.1 trillion through 2025.
Traffic demand has steadily increased over the past few decades, despite a decrease in passenger-miles driven on the nation’s major highways during the 2008 global economic recession, based on U.S. Department of Transportation reports. This trend is expected to continue, leading to more wear and tear on our roads and bridges. Addressing underlying vulnerabilities of transportation assets in cities— through conventional engineering coupled with emerging technologies—may minimize the impacts of disruptions, reduce recovery time after extreme events and, therefore, improve a city’s resilience.
Climate Hazards and Transportation Infrastructure Risk
In addition to the network’s vulnerabilities, cities and counties manage a range of extreme weather events each year, which are forecasted to increase. Transportation systems will be further challenged with sea level rise storm surge flooding, changes to snowfall patterns, more frequent freeze-thaw, temperature swings, and other extreme climatic patterns, impacting safety and functionality. To become more resilient, cities should consider incorporating extreme climate risks into policies and practices. This step may include hardening, relocating, or abandoning parts of the transportation infrastructure network, reducing vulnerabilities to climate hazards and the risks associated with their impacts.
Incorporating Redundancy in the System
Shifting toward planned redundancy in our transportation networks is a strategy to improve resilience when dealing with disruptive events, including extreme weather and emergency response and recovery. A systematic vulnerability assessment as part of a risk-based transportation asset management practice can provide the knowledge infrastructure managers need for identifying lack of redundancy in their networks and planning mitigation scenarios. Incorporating improved network redundancy in long-range plans is a key strategy for reducing risk.
Measuring Success by Setting Resilience Policies and Goals
Cities and local transportation agencies may adopt vision statements to help specify their intent to build a culture of resilience. These statements may then be further developed into more detailed policies, goals, and protocols to implement the resilience vision by different departments within the local agency, such as planning, design, maintenance, operations, information technology, and communication.
Engaging Stakeholders and Regional Partnerships
Involving stakeholders is fundamental to the successful development and implementation of a resilience plan, and will create buy-in and support. During decades of responding to flooded roads, downed power lines, felled trees, and other challenges, agencies have had to routinely coordinate with local law enforcement, emergency responders, utility crews, and other groups. Local stakeholders—both public and internal to the transportation agency—know the community best and are an important source of knowledge of the current vulnerabilities in the network. Regional or local agencies may already have informal or de facto coordination partnerships with these stakeholders. These partnerships can be extended, new partnerships can be formed and formal communication protocols can be established to help these agencies better respond to extreme events.
Cities can increase the resilience of their infrastructure networks toward stronger, more adaptable functions that allow for life and businesses to carry on with less interruption and increased reliability during and after extreme events. A risk-based transportation asset management practice with a whole-life, multi-hazard mindset is a viable solution for addressing the risk and resilience issues facing our critical transportation networks. Such an approach should address vulnerabilities, risks and redundancy of the network, as well as hazards that threaten the region. Local agencies are encouraged to set resilience goals and policies and engage local and regional stakeholders in a “resilience dialog” by creating and extending partnerships.
Ehsan N. Minaie, Ph.D., PE is Senior Consultant at Transportation Asset Management. He may be reached at firstname.lastname@example.org. Lauren M. Miller is Project Manager at Climate Change Services. She may be reached at email@example.com.