Abstract Manager

As Canadian municipalities seek alternatives to multi-lane signalized intersections that balance traffic efficiency with pedestrian safety, a promising solution has emerged from the Netherlands: the "voorrangsplein", or “priority square”, also known as a Kidney Bean intersection.

This innovative single-lane intersection design features higher capacity than a single-lane roundabout while improving pedestrian safety for crossing pedestrians and introducing lateral deflection to manage vehicle speeds.

A Kidney Bean intersection is effectively a two-way yield-controlled intersection with a large median in the centre. The layout organizes and separates conflicts geometrically so no road user needs to yield to more than one lane at a time, reducing the potential for human error. Unlike other single-lane two-way yield-controlled intersections, the layout provides storage space for left turning queues.

The design has been performing well in trial implementations where the design’s high main street capacity has allowed single-lane Kidney Bean intersections to replace multi-lane signalized intersections.

Mobycon has been assessing the design for potential trial implementations in Canada. Although the design appears significantly different than existing Canadian designs, it consists of elements that have already been introduced to Canadian road users in other intersection types such as roundabouts, Reduced Conflict Intersections and Right-in Right-out intersections.

This presentation will cover:

• Introduction to Kidney Bean intersections, why they were invented and their key design characteristics,
• Similarities and differences from existing Canadian intersection types,
• Safety and efficiency results from Kidney Bean implementations in the Netherlands, and
• Design adaptations that would be required to introduce the intersection in a Canadian context.