Project number: MF-2.1a

Funding source: Volvo Research and Educational Foundations

Performance period: 1/1/2014 to 6/1/2015

Project description

This research explores the feasibility of repurposing existing transportation infrastructure-a former freight rail viaduct now turned into a park and a former freight railroad now underused for passenger trains-for the installation of a pneumatic waste-collection and direct-rail-transfer facility in a densely developed urban center. Affixing a tube to the elevated viaduct could avoid the need for tunneling through a congested corridor, while direct rail-transfer could avoid the need for intermediate truck drayage to central transfer, processing, and disposal locations. The benefits of pneumatic collection have been shown in specific circumstances of adequate density and appropriate geographic configuration, but initial capital requirements are high compared to truck-based collection and the necessity for tunneling through crowded urban surfaces imposes an additional challenge for installing pneumatic systems in built-up areas. In this case study, the feasibility of such an installation was assessed and the economic and environmental costs of pneumatic and truck-based collection in this location were compared, as well as the costs of intermediate truck drayage and direct rail movement. The concept of repurposing such existing infrastructure was shown to be physically and operationally feasible, at lesser equivalent annual costs relative to truck collection, with mixed results in terms of environmental performance.
Truck kilometers and fuel requirements were reduced, but electrical demand for pneumatic collection caused overall energy use and greenhouse gases (GHG) to increase. Relative GHG emissions, however, would be expected to decrease in the future were the current shift to noncarbon-based fuels to continue; other public health, environmental, and economic benefits-not quantified here-may compensate for or outweigh any continuing penalties in GHG emissions.