Study: Don't Discount Operational Efficiency When Building Roads
A recent study published this summer in The International Journal of Sustainable Transportation showed how an Intelligent Transportation System (ITS) resulted in 3 times greater fuel consumption savings, and a reduction of greenhouse gas and pollution, when compared against the sum of four sustainable construction-phase strategies. These construction-phase strategies being; increasing the local content of the construction materials, reducing fossil fuel use, reusing pavement materials, and using warm-mix asphalt.
Overall the study is important as transportation accounts for 14% of the greenhouse gases globally and by implementing an ITS for incident management savings can be realised by improving the efficiency in which emergency crews can respond and clear traffic accidents to get traffic moving back to normal. This kind of implementation is of a form of operational efficiency that can be applied to existing infrastructure, primarily through the installation of traffic monitoring cameras.
The study discussed that the implementation of other ITS working in cooperation, such as on-ramp metering, could further improve the efficiency achieved. The overall results for an 8-year re-pavement schedule yielded a reduction of 2 times less CO2 emitted, and 4 times less reduction in CO, NOx and VOC emissions.
It’s important not to devalue the construction phase strategies, as over the lifetime of traffic infrastructure the majority of energy required in the system is required in the manufacturing of the materials used, roughly 60%, when compared against the construction and demolition, requiring only 3% of total energy, with maintenance and repairs making up the remaining 37%. Based on these factors an ITS system would have a bigger impact than construction-strategies as it operates in conjunction during the maintenance and repair periods of the roadway.
One thing that the study did not mention was the efficiency of the ITS-incident management during rush hour situations or where usage was exceeding optimal capacity.