At the end of 2025, Honolulu’s Department of Transportation Services celebrated the completion of a three-year project: a new roundabout at the gateway to Kailua Beach Park, a popular destination. The Kalapawai roundabout provides vital safety and circulation improvements for pedestrians, cyclists, and drivers alike.
As a part of the County and City’s Complete Streets initiative, this effort was shaped with safety, mobility, and sustainability at the center, offering stormwater management for residents in the Kailua and Lanikai neighborhoods, while accommodating increasing tourism.
Background
The roundabout is located at the intersection of Kalāheo Avenue and Kailua Road, which serves as the only car-accessible entrance to the Lanikai neighborhood, a popular residential and business district including what has gained fame as “one of the most beautiful beaches in the world” — Kailua Beach Park.
Until 2018, the intersection was a traffic triangle, with two-way traffic on South Kalāheo Avenue and stop sign-controlled intersections with Kailua Road.
For years, the area experienced heavy afternoon traffic congestion as many drivers, pedestrians, and cyclists simultaneously navigate this gateway, leading to delays in emergency response and challenges to multimodal safety and accessibility.
Piloting Changes
The city initiated a phased redesign of the intersection to ensure that the planned treatments would effectively improve safety and manage traffic operations. During the planning process, the city gathered community feedback through meetings and listening sessions where team members presented traffic simulation models and plan graphics.
Using low-cost materials, the Honolulu team reconfigured the intersection from a stop-sign-controlled intersection to a single-lane roundabout in 2018. The interim project changed a portion of South Kalāheo Avenue to one-way traffic and used road markings and signage to transform the existing traffic triangle into a roundabout. The pilot project proved successful in calming traffic, and the city chose to pursue a full reconstruction.
Photo Credit: City of Honolulu
Making the Project Permanent
The full reconstruction provided the opportunity to manage stormwater issues and prioritize people walking and biking in the Kalapawai roundabout. O’ahu’s Complete Streets Ordinance tasks cities with applying a context-sensitive solution process that integrates community context and the surrounding environment, and incorporates complete streets features into all roadway reconstruction, rehabilitation, and resurfacing projects.
In 2022, the city moved forward with the construction of the permanent project. The roundabout was designed with a non-traversable center island surrounded by a single lane, with one entry and one exit point at each approach.
The project featured:
- Upgraded lighting and landscaping in the center island, improving nighttime visibility while preserving the iconic banyan tree at the intersection.
- Raised crosswalks at each approach, calming traffic entering the roundabout, and providing safe, more visible pedestrian crossings.
- Shared-use paths and new sidewalks, providing comfortable walking and biking route connections to Kailua Town, Kalāheo Avenue, and Kailua Beach Park.
- Permeable sidewalks and gutters, as well as seven rain gardens within this project area to capture and filter stormwater, reduce runoff, and protect the nearshore waters of Kailua Bay.
- Informational signage about the history of the area.
The roundabout was under construction for about three years, beginning in November 2022. The project ran into unexpected delays due to undocumented underground utilities and the discovery of iwi kūpuna (ancestral Hawaiian remains).
Throughout these delays, the team prioritized communications about local impacts of construction detours, school traffic management, and efforts to minimize impacts on local businesses whose operations were affected by construction during peak tourism season.
The total cost of the Kalapawai Roundabout was approximately $11 million, with 80% funded by federal dollars.
Resources
Photo credits: City of Honolulu
Roundabouts slow vehicles, improve visibility, and reduce crash severity by limiting conflict points and fully eliminating dangerous head-on or high-speed right-angle collisions. Roundabout concepts can be used in both small and large intersections. As the Kalapawai pilot project shows, designers can improve safety and keep everyone moving by applying elements of roundabout design without fully reconstructing the intersection.
Check out the resources below if you’re interested in learning more:
Honolulu Resources
- “City celebrates the official opening of the Kalapawai Roundabout in Kailua”
- City and County of Honolulu Complete Streets Annual Report
- City and County of Honolulu Complete Streets Ordinance
- Poster from Meet the Cities at Designing Cities 2026
