Turbo-Roundabout
INT-TRB-02 Recommended 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.1
#Related patterns
Roundabout (Single/Multi-Lane) (INT-RAB-01) (the base pattern this scales up from), Signal (INT-SIG-03) (explicitly named on this page as the alternative not preferred even at these volumes)
#Getting there: Retrofit path options
Signal-to-roundabout conversion (RFT-INT-01)
#References
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