Protected Intersection

Image Source: FHWA

DEFINITION AND DESCRIPTION

Protected intersections use a setback or offset design to minimize conflict points and improve visibility between drivers, pedestrians, and/or bicyclists. Features of protected intersections include pedestrian refuge islands, bicycle queuing areas, corner islands, and clear crossing markings. The purpose of these features is to safeguard all road users and improve predictability. When building a protected intersection, it is essential to consider multiple factors — including accessibility requirements — to create effective solutions adapted to the surrounding roadway context.

At protected intersections, bicyclists making right turns encounter no conflicts with vehicles and left turns can be executed in two stages, allowing bicyclists to avoid merging across lanes of traffic.

Implementation Categories

Area(s) HSIP, Traffic Operations
Safety Category 4

CONSIDERATIONS

  • May be used at signalized and stop-controlled intersections.
  • May include a bicycle signal.
  • Turning radii may be smaller.
  • Corner islands and raised medians pose maintenance challenges, especially with snow and ice removal and resurfacing bicycle lanes.
  • Maintenance agreements with local governments may be used for elements of the protected intersection.

APPLICATION

  • May be considered at urban intersections with a buffered or separated bicycle lane that have high volumes of bicyclists and motorists.
  • Corner islands may consist of curb or paint and vertical separation material like flex posts. Use of mountable truck aprons can reduce turning speeds.

example

Image Source: Google Earth

Complimentary Countermeasures

  • Leading Pedestrian Interval (LPI)
  • Buffered Bike Lanes
  • Colored Pavement
  • High-Visibility Crosswalks
  • Median and Pedestrian Refuge Island

REFERENCES AND RESOURCES

FHWA. Safe System Roadway Design Hierarchy. January 2024.  FHWA-SA-22-069. https://highways.dot.gov/sites/fhwa.dot.gov/files/2024-01/Safe_System_Roadway_Design_Hierarchy.pdf 

NACTO. Don’t Give Up at the Intersection – Protected Intersections. May 2019. https://nacto.org/publication/dont-give-up-at-the-intersection/protected-intersections/

9 + 4 =

CONTACT:

Chris VanDyke

Research Scientist | Program Manager

chrisvandyke@uky.edu