1. Impacts of Climate Change on the Transportation Sector: Design and Operations Implications Michael D. Meyer, P.E., F. ASCE F.R. Dickerson Professor School of Civil and Environmental Engineering Georgia Institute of Technology

7. Highways (public) 46,873 miles of Interstate highway 115,500 miles NHS roads 3,849,259 miles of other roads 580,000 bridges Airports 5,270 public use airports Rail 95,664 Class 1 miles 15,388 regional miles 29,197 local miles 23,000 Amtrak miles Transit (directional miles) 165,854 bus miles 4,407 commuter rail 1,596 heavy rail 1,097 light rail Transit stations 1,153 commuter rail 1,023 heavy rail 723 light rail Navigable channels 26,000 miles Commercial waterway facilities Great Lakes (600 deep/150 shallow draft) 2,320 Inland shallow draft 4,298 ocean deep/1,761 shallow draft 257 locks Pipeline 60,043 miles crude 71,310 miles product 298,000 miles transmission 1,139,800 miles distribution Extent of Nation’s Transportation Infrastructure

8. 60,000 miles in FEMA coastal flood zone; 36,000 bridges within 15 nautical miles of coasts

9. Gulf Coast Study Freight Rail Lines Vulnerable to Storm Surge of 18 feet

10. Transportation infrastructure that is vulnerable to 18 feet of storm surge includes: 51% of interstate miles, 56% of arterial miles, and most transit authorities 98% of port facilities vulnerable to surge and 100% to wind 33% of rail miles operated, 43% of freight facilities, 22 airports in the study area at or below 18 feet MSL Potentially significant damage to offshore facilities

11. Fundamental to the application of engineering design standards is an understanding of how environmental factors and conditions will affect both the behavior of the overall structure itself as well as of the individual material components of the design.

12. A Typical Infrastructure Segment

13. Critical Components of Infrastructure Design 1.Subsurface conditions 2.Materials specifications 3.Cross sections/standard dimensions 4.Drainage and erosion 5.Structures 6.Location engineering

14. Water, for example, ……..

15. Road Classification Design Frequency Design Spread High Volume or < 70 km/hr (45 mph) Divided or Bi- > 70 km/hr (45 mph) Directional Sag Point 10-year 50-year Shoulder + 1 m (3 ft) Shoulder Shoulder + 1 m (3 ft) < 70 km/hr (45 mph) Collector > 70 km/hr (45 mph) Sag Point 10-year 1/2 Driving Lane + Shoulder 1/2 Driving Lane Low ADT Local Streets High ADT Sag Point 5-year 10-year 1/2 Driving Lane Suggested Minimum Design Storm Frequency and Spread. “The intensity of rainfall events may significantly affect the selection of design frequency and spread.” FHWA, Urban Drainage Design Manual, 2001.

18. Temperature, for example, …….. “Two climatic factors, temperature and moisture, are considered to influence the structural behavior of the pavement.” “With respect to subgrade strain and fatigue of cement- and limestabilized base or subbase courses, the design air temperature is the average of two temperatures: (1) the average daily mean temperature and (2) the average daily maximum temperature during the traffic period.”

19. Temperature, for example, …….. “Because of the extreme sensitivity of critical stresses in rigid pavements to temperature gradients, consideration of hourly variation in temperature conditions is necessary.”

20. Corridor Impacts

22. Primary Climatic Changes Increase in average temperatures Increase in maximum temperatures Increase in winter rainfall Reduction in summer rainfall More extreme rainfall events Reduction in snowfall Increased wind speed for worst gales Sea level rise

23. Secondary Climatic Change Impacts Longer growing season Reduction in soil moisture Change in groundwater level Flooding Reduction in fog days in winter Reduction in icy days in winter Frequency of extreme storm surges

24. Environmental Factor FacilityPossible EffectCauseFormula # Rainfall intensity /frequency increase Roadway foundation Foundation weakening Saturation 300, 301 Erosion Groundwater elevation increase Foundation and roadway loss Flooded culvert or bridge failure Roadway pavement Surface deterioration Base and sub-base saturation 403, 404, 405, 406 Surface lossFlooded culvert failure100-106 Roadside slopesSlope failure Erosion302 Soil saturation302 Roadside plantingSpecies growthHydration Bridge- water crossing Structural damage Scour100-106 Water load202 Soils pressure change Keller, Jake A.; Armstrong, Amit; Flood, Michael; Meyer, Michael D., AN APPROACH TO ADDRESSING THE IMPACTS OF CLIMATE VARIABILITY ON ROADWAY AND BRIDGE DESIGN, Paper presented at the Annual Meeting of the Transportation Research Board, Jan. 2011.

25. Environmental Factor FacilityPossible EffectCauseFormula # Rainfall intensity /frequency increase Bridge—Roadway crossing Structural damage Soils pressure change Erosion Culvert Structural damage Erosion Failure Floodwater erosion Buoyancy Storm sewerSurchargeHigh runoff rate100 Open channel Flooding High runoff rate100-108 Soil saturation302 Failure Erosion from high runoff rate and/or volume 101-108 Stream mitigation Erosion from high runoff rate and/or volume 100-108 Similar information for rainfall decrease…..

26. Environmental Factor FacilityPossible EffectCauseFormula # Temperature Rise Roadway foundation 401, 407 Roadway pavement Asphalt strength decrease Loss of viscosity404, 406 Concrete pavement heaving Thermal expansion406, 407 Roadside planting Species death or migration Erosion302 Soil saturation302 Bridge- water crossing Structural damageThermal expansion200 Bridge—roadway crossing Structural damageThermal expansion200 Culvert FloodingSnowmelt Storm sewer Open channel Keller, Jake A.; Armstrong, Amit; Flood, Michael; Meyer, Michael D., AN APPROACH TO ADDRESSING THE IMPACTS OF CLIMATE VARIABILITY ON ROADWAY AND BRIDGE DESIGN, Paper presented at the Annual Meeting of the Transportation Research Board, Jan. 2011.

27. Environmental Factor FacilityPossible EffectCauseFormula # Temperature Fall Roadway foundation Foundation weakening Freeze/thaw cycle frequency increase 401,403,404 405, 406 Roadway pavement Pavement base and surface failure 401, 407 406, 407 Roadside slopes Slope stability decrease Roadside planting Species death or migration Bridge- water crossing Structural damage Ice load201 Thermal contraction200 Bridge—roadway crossing Foundation weakening Thermal contraction200 Culvert Structural damageIce load 100-108 Capacity reduction Ice blockage Storm sewer100 Open channelIcing100-108 Keller, Jake A.; Armstrong, Amit; Flood, Michael; Meyer, Michael D., AN APPROACH TO ADDRESSING THE IMPACTS OF CLIMATE VARIABILITY ON ROADWAY AND BRIDGE DESIGN, Paper presented at the Annual Meeting of the Transportation Research Board, Jan. 2011.

28. Environmental Factor FacilityPossible EffectCauseFormula # Rise in Sea Level Roadway foundation Foundation weakening Saturation300, 301 Erosion form wave action Groundwater elevation increase 300, 301 Foundation and roadway loss Flooded culvert or bridge failure 300, 301 Roadside slopes Slope failure Erosion302 Soil saturation302 Bridge- water crossing Structural damage Scour102 Water load202 Soils pressure change Culvert Structural damageErosion FailureFloodwater erosion Storm sewerSurchargeHigher tailwater Open channel FloodingHigher tailwater FailureErosion at higher elevations

29. Environmental Factor FacilityPossible EffectCauseFormula # Wind force increase Roadside slopes Material lossWind erosion Bridge- water crossing Structural damage Wind load, increased water borne debris load 203, 204 Bridge-road crossing Structural damageWind load203, 204 Culvert Capacity reduction or structural damage Wind load, increased waterborne debris load Open channelMaterial lossWind erosion

30. Keller, Jake A.; Armstrong, Amit; Flood, Michael; Meyer, Michael D., AN APPROACH TO ADDRESSING THE IMPACTS OF CLIMATE VARIABILITY ON ROADWAY AND BRIDGE DESIGN Representative Design Formulae and Possible Effects: Hydrology

31. Keller, Jake A.; Armstrong, Amit; Flood, Michael; Meyer, Michael D., AN APPROACH TO ADDRESSING THE IMPACTS OF CLIMATE VARIABILITY ON ROADWAY AND BRIDGE DESIGN

32. Federal Highway Administration “In the coastal environment, design practices assume that flood events would essentially behave in a manner similar to a riverine environment, which assumes a 50-year storm event…result is that designs do not consider the effect of wave actions on the bridge.”

33. “State DOTs find themselves in the position that their own regulations and guidelines do not permit them to consider alternative bridge design criteria.” Recommendation: 100-year design storm that considers wave and surge effects as well as the likelihood of pressure scour.”

34. Proactive Strategies to Flood Risk Preventing flooding by improving the rainfall capture and storage capacity of a catchment (e.g. by enhancing or mimicking the water storage capacity of the soil); Increasing conveyance capacity to disperse floodwaters; Creating policies to maintain existing levels of service which incorporate climate change factors at the time of repairs or upgrades; NZ Transport Agency, Climate Change Effects on the Land Transport Network, Volume Two: Approach to Risk Management, 2009

35. Establishing physical protection measures, e.g. building stop-banks; Managing the effects of flooding by removing at- risk land use such as infrastructure and the built environment in floodplains; and Managing the expectations of communities in flood-prone areas to expect and cope with flood events. NZ Transport Agency, Climate Change Effects on the Land Transport Network, Volume Two: Approach to Risk Management, 2009

36. NCHRP 20-83(5) Climate Change and the Highway System: Impacts and Adaptation Approaches

37. Identify predominant climate change trends and factors for region Identify impact of these changes on local environmental conditions Identify vulnerabilities of highway system to these changing conditions Conduct risk appraisal of vulnerabilities and environmental changes Assess feasibility and cost effectiveness of adaptation strategies Asset AAsset BAsset C Asset X Identify affected highway agency functions Network Functions Identify trigger levels Identify critical assets in the network Change design standards Change operating strategies Change maintenance practices Change construction practices Etc. Climate Adaptation Planning Identify critical performance measures Apply triggers

38. Michigan DOT More Intense Storms – Strategy: Design assets that are less impacted by affects of Climate Change Larger hydraulic openings for bridges over waterways Heavier and lengthier armoring of river and stream banks and ditches to prevent erosion Investigate greater pavement crowns to move runoff off of pavement quicker

39. Design of additional in- system detention to meter runoff outflow Eliminate bridge design elements that could make a bridge scour critical –i.e. piers in the river, spread footings, use more sheet piling left in place Design terraced vegetated slopes using a variety of plant species

40. Design more robust pavement markings that can be seen during wet/night conditions Larger capacity pumps/pump stations for below grade freeways to prevent flooding

41. So… As primarily an “application” field, we rely on information produced by many of you Temporal and spatial scale issues “It all depends…” approach to design…for different components of a typical design We are learning now about extreme events that are exceeding our design capacities, and what this means for future approaches….infrastructure with different useful lives

42. Better approaches for incorporating uncertainty are needed … risk analysis Multiple strategy types: avoid, relocate, abandon, protect, etc. Growing interest in how we think about infrastructure vulnerability and plan for adaptation…and quite frankly we are waiting for approaches and methods based on good science for developing usable information and data

43. Identify predominant climate change trends and factors for region Identify impact of these changes on local environmental conditions Identify vulnerabilities of highway system to these changing conditions Conduct risk appraisal of vulnerabilities and environmental changes Assess feasibility and cost effectiveness of adaptation strategies Asset AAsset BAsset C Asset X Identify affected highway agency functions Network Functions Identify trigger levels Identify critical assets in the network Change design standards Change operating strategies Change maintenance practices Change construction practices Etc. Climate Adaptation Planning Identify critical performance measures Apply triggers