Understanding Green Street Design: Evidence from Three Cases in the U.S.

Abstract

World cities need more green areas to promote social, economic, and environmental well-being; the problem, however, is that the space available for green infrastructure (GI) within the built environment is limited. Finding empty, free, or underutilized spaces within the built environment to be repurposed for GI has been a challenge. Streets are public, numerous, and evenly distributed, being a desirable place to fulfill this requirement. However, they are also heavily regulated public spaces, where design is standardized, and ruled by codes and manuals. Some cities in the US have implemented an increasing number of green streets (green infrastructures within the rights-of-way with environmental purposes), because of green stormwater management federal policies. This paper aims to understand the green street design procedure, based on empirical evidence. Three cities were studied (Portland, Seattle, and Philadelphia) by means of documentary information, visual inspections, and interviews. It is of special interest to unveil how traditional street design has been modified to adopt these new green elements within rights-of-way (ROW). Results show a longer and more complex street design process for green streets, where many more disciplines intervene. These results are discussed in the light of recent movements and trends in street design.