Vortex Modular, Low Cost, Rapidly Installable Recycled Plastic Roundabout Case Studies

This paper describes status of a significant modular roundabout technology development effort, supported by both USDOT and DOD Small Business Innovation Research contracts. The resulting Vortex Roundabout technology, which concluded its final government R&D funding in 2022, is now transitioning to widespread commercial implementation.

The objective of the original 2015 DOT R&D effort was to accelerate the more widespread use of roundabouts in the USA by greatly reducing both the finished cost and installation time of traversable roundabouts, splitter islands and bike lane dividers by at least 50% compared to a conventional concrete or asphalt road construction baseline. Faster, less expensive roundabout technology should reduce barriers to entry for communities considering conversion of current stop light- or stop sign-controlled intersections to safer and more traffic-efficient roundabouts. USDOT has identified widespread implementation of roundabouts as a critical step in their path to meeting their “Zero Traffic Deaths” initiative.

The modular Vortex system has many advantages over conventional construction beyond significant cost and installation time savings, including:

• Install directly onto road surfaces with no modifications to existing conditions


• Complete design from Google maps images – reduce/remove survey costs


• Simple, Lego®-like instruction with individually serialized components tied to intersection map


• Self-templating


• Local DOT or community maintenance crews can easily install


• Reconfiguration during or after installation


• Damaged modules replaced in minutes using a socket wrench


• Modify in the field with carpentry tools if necessary


• VERY GREEN – average installation consumes about 500,000 plastic bottles

Initial feedback from early adopters of Vortex Roundabout technology generally suggests that both the cost and installation time objectives of the R&D effort have been exceeded, with some users reporting cost and installation time reductions of 75% compared to their initial project estimates for conventional construction.

This paper will describe the developmental history of the Vortex system, starting with first-generation prototype installations by GDOT (initial installation in Jackson, GA, 2017) and VDOT (Annandale, VA, 2018), and the first commercial installation in Sundre, Alberta (2017). Sundre’s decision to purchase 3 commercial Vortex roundabouts before R&D work was completed had been motivated by one of the many unique characteristics of the recycled plastic modular system – Vortex roundabouts can be installed without closing a roadway to traffic, since the modular components can be driven over during installation. The three Sundre roundabouts were located on a heavy-load/wide-load route to northern oil fields, and there was no suitable alternative to reroute traffic if the road needed to be closed for conventional construction. GDOT took advantage of another unique benefit of Vortex. Its modular construction system allowed the initially-round center circle to be reshaped to a more oval configuration in about 4 hours to adjust for a higher than designer traffic entry speed observed after the roundabout was placed into service. A final experimental roundabout was installed in San Diego (in 2022, near the San Diego Zoo.
The paper will also describe unique aspects of other Vortex installations, choosing interesting examples from commercial installations in VA, NE, FL, CA, & NC.