For infrastructure elements the essential principles are the same as for buildings, but methods and tools may be directed by government or major client organisations and should include the operator/ user costs.
Carbon emissions of vehicles using a road can be orders of magnitude more than the lifecycle carbon associated with the asset.
Carbon costs of complete infrastructure schemes, eg highway or rail link, is complex. It includes the complete construction of the highway (including structural elements) as well as operator/ user behaviours.
Carbon emissions of vehicles using a road can be orders of magnitude more than the lifecycle carbon associated with the asset, although a scheme may reduce journey distance.
The key differences are that for infrastructure the operation costs of a structure tend to be low, as they generally do not use power, but the maintenance costs may be significant over a 120 years design life.
For these structures the carbon cost of maintenance activities should include the cost of service disruptions or alternatives as well as the construction element.
These will increase with time, ie as traffic volumes increase. Measurement tools available specifically for infrastructure include:
- Highways Agency Carbon Calculation Tool for DBFO
- Network rail - RSSB Rail Carbon Tool