The design of intersections are likely to vary depending on the functions of the connecting streets, surrounding land uses and densities, the location being in central city or suburban areas, the desired vehicle operating speeds and the traffic composition.
The movement and place function of the intersecting streets is also an important consideration when designing an intersection. For example, if the street functions are not the same, for example a Local Street intersecting an Urban Connector, this may lead to different crossing requirements or demands for pedestrians on the different legs.
Consider whether an intersection is necessary or whether it can be closed, or the number of legs can be reduced or turn restrictions can be implemented to simplify the conflict points. In urban areas pedestrians should be able to cross every leg of an intersection unless the layout and context is such that there will be no demand for crossing one or more legs.
Closure of side street to vehicles, Bond Street, Wellington (Photo: James Wratt)
Intersections should be designed to be as compact as possible as this reduces pedestrian crossing exposure, slows traffic through the intersection and increases visibility for all users.
Smaller intersections with small corner radii generally allow pedestrians to cross more easily as crossing distances are minimised and crossing facilities at the intersection are more likely to be on pedestrian desire lines.
The figures below show how intersection sizes vary resulting in them being more or less walkable for pedestrians. When designing new intersections a smaller intersection with small kerb radii is likely to be better for pedestrians (ie more walkable). In a retrofit situation, making the intersection smaller (for example by removing a lane, reducing the kerb radii and/or installing kerb extensions) is likely to result in a more walkable intersection.
Cross intersection with narrow lanes, kerb extensions and small corner radii makes for a more walkable intersection with crossing distances shown by the red arrows. (Source: Canterbury Maps)
Cross intersection with wider traffic lanes and larger kerb radii makes for a less walkable intersection with crossing distances shown by the red arrows. (Source: Canterbury Maps)
High level layout and design features relevant to pedestrians include:
The intersection design and operation should focus on moving people (including pedestrians, cyclists and people in vehicles) through and across the space rather than focussing on vehicle throughput. An example could be to provide a modal priority lane to increase overall throughput of people but at a small cost to people crossing as they may have an extra lane to cross.
