Countywide Bikeways facilities should continue protection through intersections. Where feasible, provide protected intersections for separated and protected facilities. Ensure safe and comfortable crossings of arterials for bicycle boulevards.
In intersection design development, careful evaluation of the bicycle network, conflicting vehicle turn movements and volumes, and available right of way should determine the appropriate intersection design. Throughout this evaluation, safety should take top priority. Like with considerations for bikeway separation, intersection design can be challenging. The national guides and resources on this page provide some tools for navigating cost and spatial constraints. Forthcoming resources tailored to Alameda County will provide additional guidance and local project examples for phasing and implementation of All Ages and Abilities (AAA) intersection design.
National best practice resources are available through NACTO’s Don’t Give Up at the Intersection and the MassDOT Separated Bikeway Planning and Design Guide, Chapters 4 and 6. The Federal Highway Administration (FHWA) provides guidance on driveways.
NACTO Don’t Give Up at the IntersectionProtected intersection design supports the continuation of AAA facilities through intersections, especially at the intersection of multiple streets in a local bikeway network. Protected intersections use corner islands, curb extensions, and color paint to delineate bicycle and pedestrian movements across an intersection. Slower driving speeds and shorter crossing distances increase multi-modal safety, while separated bike lane crossings allow people biking to make left turns and transition to intersecting AAA bikeways without merging across lanes of through-moving traffic. Where space is limited and intersection geometry may preclude a full protected intersection, a dedicated intersection combined with dedicated signal phasing can also effectively reduce conflicts and improve bicyclist comfort at intersections. For further detail on protected and dedicated intersection design, refer to Chapter 4 of the MassDOT Guide.
Protected Intersection Diagram
MassDOT Separated Bike Lane Guide, Chapter 6Signal design along separated bike lane corridors is critical to the safe and successful implementation, especially at intersections with high conflicting turn movements. In these contexts, dedicated phasing for turning vehicles and people bicycling reduces conflicts by separating users in time. Where fully separate phasing for bicycles is not warranted, a leading bicycle/pedestrian interval can improve bicyclist visibility for turning vehicles. Chapter 6 of the MassDOT Separated Bike Lane Planning and Design Guide provides detailed considerations for phasing scheme options, signal equipment, and signal timing. The chapter provides thresholds for conflicting vehicle volumes that require consideration of dedicated phasing. NACTO’s Don’t Give Up at the Intersection provides additional resources and considerations for signal design. Key considerations for signal design include:
- Existing signal equipment and visibility
- Conflicting vehicle turn volumes
- Signal timing, phasing, and intersection clearance
- Sight lines
- Actuation and detection