Global Street Design Guide

Download caret-down
Table of Contents
gdci-stacked-color copy
Table of Contents

Global Street Design Guide

Existing Conditions

The illustration above depicts a street condition with an elevated structure carrying multiple lanes of traffic.


Elevated structures, such as fly-overs, overpasses, highways, viaducts, and rail lines, have been built in many cities to avoid signalized intersections and reduce waiting time for fast-moving, motorized through-traffic or transit. In attempting to serve the needs of vehicles on the elevated structure above, cities have created uninviting spaces for users at the street level.


Below the elevated structure, a two-way street with wide travel lanes is separated by a wide median that supports the elevated structure’s foundation.

The space under the elevated structure provides shade and protection from the rain, but is dark and unsafe. It may be used as regulated or unregulated parking and collects waste due to a lack of maintenance or stewardship.

Design Guidance

Avoid investments in new elevated structures when they only serve a singular purpose. Opportunities for improvements should be identified throughout the city where these structures exist.

This reconstruction responds to the reallocation of space at grade, while the elevated structure remains in place.

 Improve the safety and character of the space by introducing active uses underneath the elevated structure, such as pop-up stores, markets, cafés, and active recreation equipment.

 Add lighting, colors, and surface treatments. When noise levels are high, install sound-reducing panels, acoustic ceilings, or buffers to mitigate noise pollution


Redesign travel lanes in both directions to allow for wider sidewalks and new cycle facilities.

Add trees and green infrastructure elements to improve the quality of the streets and provide public health and environmental benefits, such as cleaner air, reduced heat island effect, and better stormwater management. See: Green Infrastructure.

Add mid-block crossings to increase and improve access to the newly activated central spaces. See: Pedestrian Crossings.

Introduce median-to-median crossings to position the spaces as a continuous mall.

New York City, USA

Addis Ababa, Ethiopia

Adapted by Global Street Design Guide published by Island Press.

Case Study: A8erna; Zaanstad, The Netherlands

Next Section —

Case Study: A8erna; Zaanstad, The Netherlands