Turbo-Roundabout
INT-TRB-02 Intersections & Crossings
Turbo-Roundabout
A roundabout variant using spiral lane markings and raised lane dividers to guide multi-lane traffic without the weaving conflicts a standard multi-lane roundabout allows.
Typical at: Compact Urban
Suburban and Core are edge cases. Undeveloped and Rural are unlikely pairings.
#Design notes
Reserved for higher-volume Arterial-to-Arterial junctions, where a standard roundabout's capacity is not enough but a signal is still not the preferred default. This keeps the roundabout-first philosophy intact at higher volumes rather than defaulting to a signal once traffic grows.
Unsourced claim
Formal citations for this pattern have not yet been compiled from primary sources.