Shades of Green: Modifying Sustainability Rating Systems for Transit Center Functionality

Abstract

Urban transit centers or hubs that expand walkability, increase transportation and neighborhood connectivity, and broaden infrastructure resilience are intrinsically sustainable. However, under the Leadership in Energy and Environmental Design Neighborhood Development (LEED ND) rating system, the infrastructure requirements of this built typology can preclude it from achieving sustainability certification. LEED ND is the most established certification system for projects at the district scale that seek economic development without the depletion of natural, cultural, and social surroundings. In 2015, Los Angeles Union Station, in California, through its master plan, LAUSMP, became the first transit hub to pursue LEED ND certification. Using evidence from LAUSMP, this paper outlines the inherent advantages, existing barriers, and needed expansions to achieve compatibility between transit center design and LEED ND. This paper also suggests updated metrics for connectivity and walkability to recognize linkages that occur above and below the ground plane, inclusion of incentives for carbon emissions reduction and air quality monitoring, and expanded exemptions for transit infrastructure from density and tree-lined street calculations. The paper proposes a revised version of the LEED ND rating system to create a standardized tool with which to measure sustainability across transit hubs.