Climate Change & Extreme Weather Vulnerability Assessment Framework

• Increased thermal expansion of bridge joints and paved surfaces, causing possible degradation.
• Concerns regarding pavement integrity, traffic related rutting and migration of liquid asphalt, greater need for maintenance of roads and pavement.
• Limits on periods of construction activity, and more night time work.
• Vehicle overheating and tire degradation.
• Maintenance and construction costs for roads and bridges are likely to increase as temperatures increase.
• Stress on bridge integrity due to temperature expansion of concrete joints, steel, asphalt, protective cladding, coats and sealants.
• Asphalt degradation, resulting in possible short term loss of public access or increased congestion of sections of road and highway during repair and replacement .

• Regional changes in snow and ice removal costs and environmental impacts from salt and chemical use.
• Fewer cold-related restrictions for maintenance workers.

• Changes in seasonal weight restrictions.
• Changes in seasonal fuel requirements.
• Improved mobility and safety associated with a reduction in winter weather.
• Longer construction season in colder areas.
• Freeze-thaw conditions increasing frost heaves and potholes restricting loads on roads.

• Increases in weather-related delays and traffic disruptions.
• Increased flooding of evacuation routes.
• Increases in flooding of roadways and tunnels.
• Increases in road washout, landslides and mudslides that damage roadways.
• Drainage systems likely to be overloaded more frequently and severely, causing backups and street flooding.
• Areas where flooding is already common will face more frequent and severe problems.
• If soil moisture levels become too high, structural integrity of roads, bridges, and tunnels (especially where they are already under stress) could be compromised.
• Standing water will have adverse effects on road base.
• Increased peak streamflow could affect the sizing requirement for bridges and culverts.

• Increased susceptibility to wildfires, causing road closures due to fire threat or reduced visibility.
• Increased risk of mudslides in areas deforested by wildfires.

• Benefits for safety and reduced interruptions if frozen precipitation shifts to rainfall.
• Increased risk of floods, landslides, slow failures and damage to roads if precipitation changes from snow to rain in winter and spring thaws.
• Increased variation in wet/dry spells and decrease in available moisture may cause road foundations to degrade.
• Degradation, failure and replacement of road structures due to increases in ground and foundation movement, shrinkage and changes in groundwater.
• Increased maintenance and replacement costs of road infrastructure.
• Short term loss of public access or increased congestion to sections of road and highway.

• More frequent and potentially more extensive emergency evacuations.
• More debris on roads, interrupting travel and shipping.
• Bridges, signs, overhead cables and other tall structures are at risk from increased wind speeds.
• Increased threat to stability of bridge decks.
• Decreased expected life-time of highways exposed to storm surge.
• Risk of immediate flooding, damage caused by force of water and secondary damage caused by collisions with debris.
• Erosion of coastal highways and land supporting coastal infrastructure.
• Damage to signs, lighting fixtures, and supports
• Reduced drainage rate of low-lying land after rainfall and flooding events.

Three breaches in NC12 after Hurricane Irene Photo Credit: Tom MacKenzie, US FWS

Rising sea levels (leading to higher storm surge, increased salinity of rivers and estuaries, flooding)

• Amplifies effect of storm surge, causing more frequent interruptions to coastal and low-lying roadway travel due to storm surges.
• Amplifies effect of storm surge, causing more severe storm surges requiring evacuation.
• Permanent inundation of roads or low lying feeder roads in coastal areas. Reduces route options/redundancy.
• More frequent or severe flooding of underground tunnels and low-lying infrastructure.
• As the sea level rises, the coastline will change and highways that were not previously at risk to storm surge and wave damage may be exposed in the future.
• Erosion of road base and bridge supports.
• Highway embankments at risk of subsidence/heave.
• Bridge scour.
• Reduced clearance under bridges.
• Increased maintenance and replacement costs of tunnel infrastructure.