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Sensitivity Matrix

IV(b) Temperature - Additional Detail

Asset Categories   Temperature - Additional Detail
Mode Sub-Mode Important Impact-Asset Relationships Threshold Mobile-Specific Detail
Bridges Bridge (Superstructure)      
Bridge (Substructure)      
Operator Houses (movable bridges) and electrical parts      
Roads and Highways Paved road surface Asphalt binder is designed to withstand temperatures up to a certain threshold. Incremental temperature increases up until that point are not likely to cause much damage. However, in the case of Mobile, it is possible that temperature changes will increasingly cross that threshold. In the Pg 64-22 grade, the number 64 stands for the average 7-day high pavement temperature (consecutive days) 20 mm below the surface. The relationship between that temperature and the ambient temperature is given by the following equation: T20mm = (Tair - 0.00618 lat2 + 0.2289 lat + 42.2) (0.9545) - 17.78
Where,
T is expressed in °C and the latitude is in degrees. Lat2 means latitude squared. [61]
For example, there was a recent hot spell in Birmingham where the temperature did not drop below 100 even at night and as a result a lot of the pavement softened and rutted, particularly in areas of high truck traffic. Damage is particularly bad in areas where trucks stop - since the force of stopped "shoves" the soft pavement and causes damage. [43]
Road substructure (gravel base, substructure)      
Unpaved roads      
Stormwater drainage (culverts, side drains, etc)      
Highway, road and street signs and traffic lights      
Highway and road traffic and service      
Railroads Electrical Equipment (gates/flashers and signal bungalows) Temperatures damaging wiring and housing of electrical equipment through expansion of metal. [49] Risk of electrical malfunctions increase with increasing temps due to expansion of materials. [49]  
Railroad Tracks, Ties, and Ballast Rails that reach threshold temperature for buckling are more likely to "give" under normal railroad travel and operations. [49, 57, 2, 54, 8, 60] Buckling evident above threshold temps. 22°C (72 °F) is considered ideal neutral temperature for stable tracks. [49, 54, 2, 11, 48]  
Railroad services (i.e., operations) Weakened or kinked tracks threaten service continuity. Environmental conditions for workers also of concern. [2, 57, 8, 60, 49] Temps above 90 °F exacerbate risk of rail expansion, increasing risk for derailment. Heat indices above 105 °F increase health and safety risks for rail personnel potentially leading to operational delays. [49]  
Airports/ Heliports Runway and navigational aids Runway length required by standards increases with increasing temperatures. [6, 48, 60] U.S. Climate Change Science Program (2008) found that for 1.8 to 6 degree Celsius temperature increase in August, runway length would need to increase by 9 to 46 m (30 to 150ft) for small aircraft and by 12 to 219 m (40 to 720 ft) for large general aviation aircraft. These runway increases are quite small, and trends in aircraft design will likely enable shorter runway take-off requirements for new aircraft, which could mitigate this effect to some extent. [60]  
Aircraft      
Airfield buildings and structures (e.g., terminal buildings, hangers, air traffic control tower)      
Services and airport/ heliport operations (e.g., flight departures and arrivals, baggage/cargo transfers, ground transportation)   Extreme heat can limit aircraft lift. Effect is continuous, so there is no exact threshold.
Natural Oil and Gas Pipelines Pipelines, aboveground Temperature shifts are not expected to have direct or indirect impacts on pipelines. [60] Soil cover and water moderates temperature effects, pipelines already designed to accommodate significant temperature variations. [60]  
Pipelines, underground  
Pipelines, offshore  
Aboveground infrastructure (e.g., compressor stations, metering stations, other buildings, structures)      
Utilities for pipelines - electricity      
Electric Power Systems Electric Power Systems Stability of poles can be compromised through rot, increased prevalence of insects that degrade quality of wood in the area. Uncertain how historical and/or future changes in climate have influenced these factors. [55]    
Marine Ports, Terminals, and Waterways Electrical Equipment      
Terminal Buildings      
Channels      
Piers, wharves, and berths      
Port services (i.e., operations)      

*Note dollar amounts are not adjusted for inflation.

Updated: 03/27/2014
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