- Turnaround (road)
In the field of
road transport , a turnaround is a type of junction that allows traffic travelling in one direction on a road to efficiently make a U-turn (to reverse course and travel the opposite direction) typically without backing up or making dangerous maneuvers in the middle of the traffic stream. While many junction types permit U-turns, the term turnaround often applies to road junctions built specifically for this purpose.Junction types designed specifically for U-Turns
The following road junction types are designed specifically to allow U-Turns.
* The
Texas U-turn allows traffic travelling on one direction of a one-wayfrontage road , running parallel to a highway, to cross the highway (via a grade separation) and turn onto the other frontage road, traveling in the opposite direction. The term refers to roadworks which are specially built for this purpose; and does not refer to use of an intersecting roadway to navigate between frontage roads. [http://www.texhwyman.com/tex.htm Texas Highwayman's Primer on Texas Highways]* The
Michigan left allows traffic travelling in one direction on adivided highway (typically one withtraffic light s and at-grade intersections) to perform a U-turn through the median.* A
cul-de-sac allows a smooth turnaround at the end of adead end street.* Sometimes, a modified reverse jughandle is used to permit U-turns. Traffic wishing to turn around executes a left turn (across oncoming traffic) onto the jughandle, but rather than merging onto a crossing road, the jughandle turns back and merges into the road just left, in the opposite direction. An example of this can be found on a divided section of
U.S. Highway 101 south ofLincoln City, Oregon . [http://local.live.com/default.aspx?v=2&ss=linconl%20city%2c%20or&cp=44.84326~-124.048817&style=a&lvl=17&scene=3660935 MSN Local.live.com satellite imagery of turnaround (blurry image)]Junction types which permit U-Turns
The following junction types typically permit U-turns but are not designed specifically for that purpose.
* Normal at-grade intersections on divided highways often allow traffic travelling on the divided highway to perform a U-turn, often when there is a green light for traffic turning onto the side road, crossing the opposing lanes (left turns in countries where traffic moves on the right; right turns in countries where traffic moves on the left).
*
Traffic circle s androundabouts make turning around rather easy.* Many freeway interchanges with
surface street s are configured so that traffic on the freeway can exit onto the surface street, and re-enter the freeway in the opposite direction.* The
cloverleaf interchange permits turning around by navigating two consecutive "leaves" of the clover pattern.External links
*
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