Intersections can generally be classified into three main types: Simple, T-Intersections, and Complex Intersections. Each type presents different design considerations and opportunities to improve safety, accessibility, and clarity.
Simple Intersections
Usage: Wide
Simple (or standard) intersections occur where two streets meet at a generally perpendicular angle and form a four-legged crossing with four crosswalks. This condition is typical in areas with a traditional street grid and characterizes much of New York City. These intersections are preferred as they promote predictable and legible movements for all users.
T-Intersections
Usage: Wide
T-Intersections typically occur when streets intersect at a feature like a park, a large property (e.g. NYCHA campus or a super-block development), or topographical conditions that result in a Step Street or significant slope. These intersections have similar features to a Simple Intersection, but three legs and typically three crosswalks.
Complex Intersections
Usage: Limited
Complex intersections occur where more than two streets converge or meet at irregular angles. These locations often present challenges for signalization, navigation, and safety due to non-standard geometry and high user volumes.
Where possible, complex intersections should be redesigned to make them as regular and orthogonal as possible—simplifying operations and reducing conflicts. Realigning approaches, closing redundant legs or slip lanes, and reallocating excess roadway can improve safety and create opportunities to support community life by transforming reclaimed areas into Pedestrian Plazas.
Enhanced Crossings
Usage: Limited
Enhanced crossings allow for the installation of crosswalks and other intersection features at uncontrolled intersections (i.e. intersections with no signals or stop signs). These are generally pursued where there is a significant volume of pedestrians crossing the street, but the intersection does not meet the warrant thresholds for a control. DOT generally only marks crosswalks that meet U.S. federal guidelines for traffic controls determined by the MUTCD. Enhanced Crossings are a standard treatment that meet the community need for marked crossings when traffic controls are not appropriate.