Visibility and sight distance are parameters central to the inherent safety of intersections, driveways, and other potential conflict points.
Intersection design should facilitate eye contact between street users, ensuring that motorists, bicyclists, pedestrians, and transit vehicles intuitively read intersections as shared spaces. Visibility can be achieved through a variety of design strategies, including intersection “daylighting,” design for low-speed intersection approaches, and the addition of traffic controls that remove trees or amenities that impede standard approach, departure, and height sight distances. Sight line standards for intersections should be determined using target speeds, rather than 85th-percentile design speeds. This prevents wide setbacks and designs that increase speeds and endanger pedestrians.
See Design Speed
City of Portland, Oregon, “Uncontrolled Intersections and You,” accessed June 3, 2013.
New Jersey, New Jersey statutes annotated: Title 39:4 Motor vehicles and traffic regulation.
“Guidelines for Planting Street Trees,” San Francisco Department of Public Works, accessed June 3, 2013.
Complete Streets Complete Networks—A Manual for the Design of Active Transportation (Chicago: Active Transportation Policy, 2012).
Project for Public Spaces, “Lighting Use & Design,” accessed June 3, 2013.
Adapted from the Urban Street Design Guide, published by Island Press.