addressing climate change adaptation in regional transportation plans

Addressing Climate Change Adaptation in Regional Transportation PlansA Guide for California MPOs and RTPAstransportation infrastructure. At one extreme, more frequent precipitationchanges are likely to affect the flooding of tunnels, coastal highways, airportrunways, and railways, as well as more frequent landslides. At the otherextreme, they could increase the chance of drought and wildfires that couldrequire more frequent repair and maintenance. For transportation in California,sea-level rise is a particularly critical climate stressor. A study by the PacificInstitute estimates that a 1.4-meter, projected sea-level rise places coastalproperty at risk in the order of $100 billion (Heberger et al., 2009). A substantialamount of ground transportation infrastructure, including 2,500 miles of roadsand railroads, is projected to be at a growing risk from storm-related coastalflooding due to accelerated sea-level rise (Heberger et al., 2009).2.2 REASONS FOR CALIFORNIA MPOS AND RTPASTO BE PROACTIVEClimate factors are likely to affect decisions in every phase of the transportationmanagement process: from long-range planning and investment; throughproject design and construction; to management and operations of theinfrastructure; and system evaluation. California MPOs and RTPAs will have toface increasing uncertainty in the upcoming years – uncertainty from climatechange predictions, uncertainty in the ways that climate will affect the activitiesof their operations, and uncertainty in the performance of their assets. Thus, it isimportant to start thinking and planning for climate change adaptation.Planning for the future can benefit the present. MPOs and RTPAs may findthat projected climate change impacts are more extreme versions of climatevariability and extreme climate events they are facing today. Planning forthese events, such as sea-level rise combined with storm surge, may require abetter understanding of the role of transportation to emergency response andevacuation. If alternate routes to highways in low-lying coastal areas aremapped out, they can provide a blueprint for emergency planning andevacuation.Proactive planning can be more effective and less costly than respondingreactively to climate change impacts as they happen. Taking proactive stepscan save money. For instance, more frequent and intensive flooding couldrequire the reinforcement or armoring of infrastructure and port facilities,resulting in investments in maintenance that extend service life and canrequire less total cost over the infrastructure lifetime.Thinking strategically can reduce future risks. MPOs and RTPAs can createopportunities for modifying present-day policies and practices that canensure resiliency to climate change. For example, zoning that concentratesdevelopment in an area at risk to future sea-level rise and coastal floodingcan be altered before that area is built out. Some MPOs have already begunto adopt more flexible, scenario-based approaches in developing their long-2-2 Cambridge Systematics, Inc.