Design process

The 12th Avenue green street project was initiated by landscape architect Kevin Robert Perry of the City of Portland bureau of environmental services. The design process brought together a design and engineering team from various departments in the City of Portland authority, including transport, maintenance and environmental services. As it was a small-scale project it was designed and implemented relatively quickly, taking just under six months from project inception to completion. Because the project fell into the city’s right-of way land use category, it did not have to go through a formal land use review. Instead, a review was co-ordinated with the adjacent property owner, Portland State University, which gave its approval.

Design challenges

The designers wanted to enhance the quality of the street environment by increasing the amount of green space and creating a landscape buffer between pedestrians and vehicles. Large canopy trees and planting were chosen to provide cooling and shade during the summer and to improve habitat connectivity. The biggest problem they faced was finding a way to accommodate pedestrians, vehicle parking, trees, landscaping, street lighting, signage and storm-water planters within a 2.4 metre-wide space.

Accessibility

Early in the design process thought was given to ensuring enough pavement area was provided for people getting in and out of vehicles with wheelchairs or pushchairs. Curb extensions have made the street better for cyclists and pedestrians by shortening the crossing distance in the street intersection and improving visibility. A small sign has been put up near the planters to explain how the system works and to tell people where they can find more information on sustainable storm-water management.