Barrier transfer machine
Encyclopedia
Barrier transfer machines, also known as zipper machines, are heavy vehicles used to transfer Jersey barrier
s or other concrete lane dividers used to relieve traffic congestion during rush hours.
The vehicle contains an S-shaped channel in its undercarriage which lifts the barrier segments (which may weigh over a thousand pounds) off the road surface and transfers them over to the other side of the lane, reallocating traffic lanes to accommodate increased traffic for the currently dominant (tidal) direction. These barriers are linked together with steel connectors to create a formidable but flexible safety barrier.
Moveable barriers are in permanent use in such cities as Auckland
(Auckland Harbour Bridge
); Philadelphia, Pennsylvania; New York; Honolulu, Hawaii
; San Juan, Puerto Rico
; Boston, Massachusetts, Washington, D.C.
, Dallas, Texas
; and Sydney, Australia; while many other cities use them temporarily during construction work.
A variant of the machine uses two narrower machines running in tandem. This setup tends to be used in reversible lane
s when the movable barrier is used to divide two directions of traffic--the narrower machines are less of an impediment to traffic in either direction. The lanes created by the machine are sometimes referred to as zipper lanes.
Jersey barrier
A Jersey barrier or Jersey wall is a modular concrete barrier employed to separate lanes of traffic. It is designed to both minimize vehicle damage in cases of incidental contact while still preventing crossover in the case of head-on accidents....
s or other concrete lane dividers used to relieve traffic congestion during rush hours.
The vehicle contains an S-shaped channel in its undercarriage which lifts the barrier segments (which may weigh over a thousand pounds) off the road surface and transfers them over to the other side of the lane, reallocating traffic lanes to accommodate increased traffic for the currently dominant (tidal) direction. These barriers are linked together with steel connectors to create a formidable but flexible safety barrier.
Moveable barriers are in permanent use in such cities as Auckland
Auckland City
Auckland City was the city and local authority covering the Auckland isthmus and most of the islands of the Hauraki Gulf, in the North Island of New Zealand. On 1 November 2010 it was amalgamated into the wider Auckland Region under the authority of the new Auckland Council...
(Auckland Harbour Bridge
Auckland Harbour Bridge
The Auckland Harbour Bridge is an eight-lane box truss motorway bridge over the Waitemata Harbour, joining St Marys Bay in Auckland with Northcote in North Shore City, New Zealand. The bridge is part of State Highway 1 and the Auckland Northern Motorway...
); Philadelphia, Pennsylvania; New York; Honolulu, Hawaii
Honolulu, Hawaii
Honolulu is the capital and the most populous city of the U.S. state of Hawaii. Honolulu is the southernmost major U.S. city. Although the name "Honolulu" refers to the urban area on the southeastern shore of the island of Oahu, the city and county government are consolidated as the City and...
; San Juan, Puerto Rico
San Juan, Puerto Rico
San Juan , officially Municipio de la Ciudad Capital San Juan Bautista , is the capital and most populous municipality in Puerto Rico, an unincorporated territory of the United States. As of the 2010 census, it had a population of 395,326 making it the 46th-largest city under the jurisdiction of...
; Boston, Massachusetts, Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
, Dallas, Texas
Dallas, Texas
Dallas is the third-largest city in Texas and the ninth-largest in the United States. The Dallas-Fort Worth Metroplex is the largest metropolitan area in the South and fourth-largest metropolitan area in the United States...
; and Sydney, Australia; while many other cities use them temporarily during construction work.
A variant of the machine uses two narrower machines running in tandem. This setup tends to be used in reversible lane
Reversible lane
A reversible lane , called a counterflow lane or contraflow lane in transport engineering nomenclature, is a lane in which traffic may travel in either direction, depending on certain conditions...
s when the movable barrier is used to divide two directions of traffic--the narrower machines are less of an impediment to traffic in either direction. The lanes created by the machine are sometimes referred to as zipper lanes.