Characteristics of Mini Roundabouts

Section 1

Characteristics of Mini Roundabouts

A mini roundabout is a type of intersection that can be used at physically constrained locations in place of stop controlled or signalized intersections to help improve safety problems and reduce ex cessive delays at minor approaches 1 Figure 1 illustrates the design features of a mini roundabout these features are described further later in this summary Mini roundabouts generally have an inscribed circle that is small

curb lines if

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adequate

enough

space is

to

way or within the existing of stay within the existing right

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larger

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Mini operate available roundabouts

in the

same manner as

roundabouts with yield control on all entries and counterclockwise circulation around a mountable traversable central island

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roundabouts Mini

traffic circles left turning vehicles must turn in front

traffic circles

of the central island potentially conflicting with other

are distinguished from neighborhood primarily by their traversable islands and to yield control on all approaches which allows them traffic I function as other roundabouts do Neighborhood circles are typically built at the intersections of local or aesthetics streets for reasons of traffic calming and way or all way stop They typically are operated as two I controlled intersections and frequently do not include channelization to guide approaching traffic into the circulatory roadway At some neighborhood

circulating traffic I

To help promote safe operations the design of mini roundabouts generally aligns passenger cars on the approach in such a way as to naturally follow the circulatory roadway and minimize running over the

raised I

central Island to the

extent

possible

Due to the small

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footprint lar e vehicles are typically required to over run the fully traversable central island as shown in Figure 1

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Trucks ma Y need to P ass over central island

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Central island sized to

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provide deflection for passenger

Entrance line and splitter island defined by inscribed circle diameter or by swept path of large vehicles

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cars i

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Splitter island mountable or painted yellow

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Boundary of inscribed circle

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Figure 1 Design Features of a Mini Roundabout FHWA

Roundabouts Mini

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