Assessing ‘carbon balance’ of intelligent transport schemes Available to Purchase

This paper considers how carbon costs and savings can be estimated and used as a tool, in a similar manner to the standard financial assessment tools, when assessing intelligent transport systems (ITS) schemes. This is a novel approach and one that may provide useful insights when considering investments in transport systems, especially in the light of climate change and rising energy costs. The scope and application of ITS is too broad to be considered in its entirety in one paper, so this paper considers one example—the M25 junctions 15 to 16 variable mandatory speed limit (VMSL) scheme—as a case study to determine both the carbon dioxide (CO₂) costs and benefits over the life of the project. ITS can be used to reduce harmful emissions, contributing to enhanced air quality and reduced effects on climate change from CO₂. The CO₂ produced when constructing, operating and eventually decommissioning these schemes is, however, often overlooked. This paper considers the balance in carbon use between the building and operating of ITS-based traffic congestion management schemes and the resultant reduction in emissions from traffic. While the calculations relate to the specific example (M25 VMSL), the principals can be adopted, and further refined, for other ITS schemes.