Contraflow lane reversal - AbsoluteAstronomy.com

Contraflow lane reversal refers to plans that alter the normal flow of traffic, typically on a controlled-access highway

Highway

A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

(such as a freeway or motorway), to either aid in an emergency evacuation

Emergency evacuation

Emergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...

(the most common usage of the term in the United States) or, as part of routine maintenance activities, to facilitate widening or reconstruction of one of the highway's carriageway

Carriageway

A carriageway consists of a width of road on which a vehicle is not restricted by any physical barriers or separation to move laterally...

s (the most common usage in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

).

Usually, the term is used to refer to reversal of lanes which are normally configured for travel in one direction; routinely changing the configuration of reversible lanes (such as during rush hour

Rush hour

A rush hour or peak hour is a part of the day during which traffic congestion on roads and crowding on public transport is at its highest. Normally, this happens twice a day—once in the morning and once in the evening, the times during when the most people commute...

) is not normally considered contraflow lane reversal.

For use in emergency evacuation

In an emergency evacuation, contraflow lane reversal roughly doubles the number of lanes available for evacuation traffic

Traffic

Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...

. Crossover sections are used to move outgoing traffic to these lanes. All incoming traffic is blocked until the end of the evacuation.

Contraflow lane reversal is usually done on freeways and other controlled-access roadways; however, some examples listed below (particularly in South Carolina) are divided and undivided roadways. Use of contraflow lane reversal is generally considered to be an emergency measure, as the contraflow lanes (and any associated ramps at interchanges) lack proper signage, signals, and other traffic control devices needed to orderly conduct traffic in the opposite direction. Generally, a significant number of police officers or other officials are needed to manually direct traffic during a lane reversal (especially at interchanges, where ramp traffic in the wrong direction must intersect with other roadways operating normally).

Hurricane evacuation

Beginning in the 1990s, many states in the Southeastern United States

Southeastern United States

The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....

adopted hurricane evacuation route

Hurricane evacuation route

A hurricane evacuation route is a highway in the United States that is a specified route for hurricane evacuation.Along the Gulf Coast, hurricane evacuation routes lead north and west for up to hundreds of miles to the safest major city. Along the Atlantic Coast, routes lead west. They are marked...

s from coastal areas using contraflow lane reversals on Interstate Highways. State highway departments have coordinated on plans for traffic direction with state highway patrol

Highway patrol

A highway patrol is either a police unit created primarily for the purpose of overseeing and enforcing traffic safety compliance on roads and highways, or a detail within an existing local or regional police agency that is primarily concerned with such duties.Duties of highway patrols or traffic...

agencies, constructed highway median crossovers, and installed signage for drivers and barriers and swing arms to inhibit wrong-way collisions.

Most evacuation plans only involve a single state; however, the states of Louisiana

Louisiana

Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

and Mississippi

Mississippi

Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

have developed coordinated plans to evacuate the New Orleans metropolitan area

New Orleans metropolitan area

New Orleans–Metairie–Kenner, or the Greater New Orleans Region is a metropolitan area designated by the United States Census encompassing seven parishes in the state of Louisiana, centering on the city of New Orleans...

using Interstate 55

Interstate 55

Interstate 55 is an Interstate Highway in the central United States. Its odd number indicates that it is a north–south Interstate Highway. I-55 goes from LaPlace, Louisiana at Interstate 10 to Chicago at U.S. Route 41 , at McCormick Place. A common nickname for the highway is "double...

and Interstate 59

Interstate 59

Interstate 59 is an Interstate Highway in the southern United States. Its southern terminus is near Slidell, Louisiana, a suburb of New Orleans, at an intersection with Interstate 10 and Interstate 12, its northern terminus is at Wildwood, Georgia, at an intersection with Interstate 24.The road's...

Current contraflow evacuation plans exist for:

Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
- Mobile
  Mobile, Alabama
  Mobile is the third most populous city in the Southern US state of Alabama and is the county seat of Mobile County. It is located on the Mobile River and the central Gulf Coast of the United States. The population within the city limits was 195,111 during the 2010 census. It is the largest...
  
  via I-65
  Interstate 65
  Interstate 65 is a major Interstate Highway in the United States. The southern terminus is located at an intersection with Interstate 10 in Mobile, Alabama, and its northern terminus is at an interchange with Interstate 90 , U.S. Route 12, and U.S...
Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
- Jacksonville
  Jacksonville, Florida
  Jacksonville is the largest city in the U.S. state of Florida in terms of both population and land area, and the largest city by area in the contiguous United States. It is the county seat of Duval County, with which the city government consolidated in 1968...
  
  , via I-10
  Interstate 10
  Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
- Pensacola
  Pensacola, Florida
  Pensacola is the westernmost city in the Florida Panhandle and the county seat of Escambia County, Florida, United States of America. As of the 2000 census, the city had a total population of 56,255 and as of 2009, the estimated population was 53,752...
  
  , via I-10
  Interstate 10
  Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
  
  (eastbound)
- South Florida
  South Florida metropolitan area
  The South Florida metropolitan area, also known as the Miami metropolitan area, and designated the Miami–Fort Lauderdale–Pompano Beach, FL Metropolitan Statistical Area by the U.S...
  
  (Miami/Fort Lauderdale), via Florida's Turnpike
  Florida's Turnpike
  Florida's Turnpike , designated as the Ronald Reagan Turnpike, and originally known as the Sunshine State Parkway is a north–south toll road that runs through 11 counties in the Florida peninsula, from U.S...
  
  and Alligator Alley
  Alligator Alley
  Alligator Alley is a section of Interstate 75 and State Road 84 extending from Naples on the west coast of Florida to Weston on the east...
- Southwest Florida
  Southwest Florida
  Southwest Florida is a region of Florida , United States located along its gulf coast, south of the Tampa Bay area, west of Lake Okeechobee and mostly north of the Everglades...
  
  , via I-75
  Interstate 75
  Interstate 75 is a major north–south Interstate Highway in the Great Lakes and Southeastern regions of the United States. It travels from State Road 826 and State Road 924 in Hialeah, Florida to Sault Ste. Marie, Michigan, at the Ontario, Canada, border...
- The Space Coast
  Space Coast
  The Space Coast is a region in the U.S. state of Florida around Kennedy Space Center , where NASA launched space shuttles until the last one on July 8th, 2011 at 11:29am; and Cape Canaveral Air Force Station, site of unmanned civilian and military space launches...
  
  , via SR 528
- Tampa Bay
  Tampa Bay Area
  The Tampa Bay Area is the region of west central Florida adjacent to Tampa Bay. Definitions of the region vary. It is often considered equivalent to the Tampa-St. Petersburg-Clearwater Metropolitan Statistical Area defined by the United States Census Bureau. The Census Bureau currently...
  
  , via I-4
  Interstate 4
  Interstate 4 is a intrastate Highway located entirely within the state of Florida, United States. It goes from Interstate 275 in Tampa, Florida to Interstate 95 at Daytona Beach, Florida . It also has the Florida Department of Transportation designation of State Road 400, but only a small...
Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
- Savannah
  Savannah, Georgia
  Savannah is the largest city and the county seat of Chatham County, in the U.S. state of Georgia. Established in 1733, the city of Savannah was the colonial capital of the Province of Georgia and later the first state capital of Georgia. Today Savannah is an industrial center and an important...
  
  , via I-16
  Interstate 16
  Interstate 16 , also known as Jim Gillis Historic Savannah Parkway or State Route 404 , is an intrastate Interstate Highway located entirely within the state of Georgia, United States...
Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
- Lafayette
  Lafayette, Louisiana
  Lafayette is a city in and the parish seat of Lafayette Parish, Louisiana, United States, on the Vermilion River. The population was 120,623 at the 2010 census...
  
  , via I-49
  Interstate 49
  Interstate 49 is currently an intrastate Interstate Highway located entirely within the state of Louisiana in the southern United States. Its southern terminus is in Lafayette, Louisiana, at Interstate 10 while its northern terminus is in Shreveport, Louisiana, at Interstate 20.-Route...
- Lake Charles
  Lake Charles, Louisiana
  Lake Charles is the fifth-largest incorporated city in the U.S. state of Louisiana, located on Lake Charles, Prien Lake, and the Calcasieu River. Located in Calcasieu Parish, a major cultural, industrial, and educational center in the southwest region of the state, and one of the most important in...
  
  , via I-10
  Interstate 10
  Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
  
  and I-210
  Interstate 210 (Louisiana)
  Interstate 210 in Louisiana is a bypass route in Lake Charles, in the southwestern part of the state. As a bypass of I-10, both of the ends of I-210 meet with I-10.-Route description:...
- New Orleans metropolitan area
  New Orleans metropolitan area
  New Orleans–Metairie–Kenner, or the Greater New Orleans Region is a metropolitan area designated by the United States Census encompassing seven parishes in the state of Louisiana, centering on the city of New Orleans...
  
  , via I-10
  Interstate 10
  Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
  
  , I-12
  Interstate 12
  Interstate 12 is an intrastate Interstate Highway located entirely within the state of Louisiana. I-12 starts in Baton Rouge at Interstate 10, and travels along the North Shore of Lake Pontchartrain before ending at the intersection of Interstate 10 and Interstate 59 near Slidell...
  
  , I-55
  Interstate 55
  Interstate 55 is an Interstate Highway in the central United States. Its odd number indicates that it is a north–south Interstate Highway. I-55 goes from LaPlace, Louisiana at Interstate 10 to Chicago at U.S. Route 41 , at McCormick Place. A common nickname for the highway is "double...
  
  , I-59
  Interstate 59
  Interstate 59 is an Interstate Highway in the southern United States. Its southern terminus is near Slidell, Louisiana, a suburb of New Orleans, at an intersection with Interstate 10 and Interstate 12, its northern terminus is at Wildwood, Georgia, at an intersection with Interstate 24.The road's...
  
  , and the Lake Pontchartrain Causeway
  Lake Pontchartrain Causeway
  The Lake Pontchartrain Causeway, or the Causeway, consists of two parallel bridges crossing Lake Pontchartrain in southern Louisiana, United States. The longer of the two bridges is long...
Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
- Ocean City
  Ocean City, Maryland
  Ocean City, sometimes known as OC, or OCMD, is an Atlantic Ocean resort town in Worcester County, Maryland, United States. Ocean City is widely known in the Mid-Atlantic region of the United States and is a frequent destination for vacationers in that area...
  
  , via US 50
  U.S. Route 50 in Maryland
  U.S. Route 50 is a major east–west route of the U.S. Highway system, stretching just over from Ocean City, Maryland on the Atlantic Ocean to West Sacramento, California. In the U.S. state of Maryland, US 50 exists in two sections. The longer of these serves as a major route connecting...
  
  and Maryland Route 90
  Maryland Route 90
  Maryland Route 90 is a state highway in the U.S. state of Maryland. Known as the Ocean City Expressway, the state highway runs from U.S. Route 50 near Whaleyville to MD 528 in Ocean City. MD 90 is a two-lane expressway that provides one of the main access routes to Ocean City, especially the...
Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
- Mississippi Gulf Coast
  Mississippi Gulf Coast
  The Mississippi Gulf Coast refers to the three Mississippi counties which lie on the Gulf of Mexico: Hancock, Harrison and Jackson counties.The region was severely damaged by Hurricane Camille in 1969 and again by Hurricane Katrina in 2005....
  
  , via I-59
  Interstate 59
  Interstate 59 is an Interstate Highway in the southern United States. Its southern terminus is near Slidell, Louisiana, a suburb of New Orleans, at an intersection with Interstate 10 and Interstate 12, its northern terminus is at Wildwood, Georgia, at an intersection with Interstate 24.The road's...
- New Orleans metropolitan area
  New Orleans metropolitan area
  New Orleans–Metairie–Kenner, or the Greater New Orleans Region is a metropolitan area designated by the United States Census encompassing seven parishes in the state of Louisiana, centering on the city of New Orleans...
  
  , via I-55
  Interstate 55
  Interstate 55 is an Interstate Highway in the central United States. Its odd number indicates that it is a north–south Interstate Highway. I-55 goes from LaPlace, Louisiana at Interstate 10 to Chicago at U.S. Route 41 , at McCormick Place. A common nickname for the highway is "double...
New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
- Jersey Shore
  Jersey Shore
  The Jersey Shore is a term used to refer to both the Atlantic coast of the U.S. state of New Jersey and the adjacent resort and residential communities. . The New Jersey State Department of Tourism considers the Shore Region, Greater Atlantic City, and the Southern Shore to be distinct, each having...
  
  , via Route 47/Route 347, Atlantic City Expressway
  Atlantic City Expressway
  The Atlantic City Expressway is a , controlled-access toll road in New Jersey, managed and operated by the South Jersey Transportation Authority...
  
  , Route 72/Route 70, Route 35, and Route 138/I-195
  Interstate 195 (New Jersey)
  Interstate 195 is an auxiliary route of the Interstate Highway System located in the U.S. state of New Jersey. Its western end is at I-295 and Route 29 just south of Trenton, New Jersey in Hamilton Township, Mercer County while its eastern end is at the Garden State Parkway, Route 34 and Route...
North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
- Wilmington
  Wilmington, North Carolina
  Wilmington is a port city in and is the county seat of New Hanover County, North Carolina, United States. The population is 106,476 according to the 2010 Census, making it the eighth most populous city in the state of North Carolina...
  
  , via I-40
  Interstate 40
  Interstate 40 is the third-longest major east–west Interstate Highway in the United States, after I-90 and I-80. Its western end is at Interstate 15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 and North Carolina Highway 132 in Wilmington, North Carolina...
South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
- Beaufort
  Beaufort, South Carolina
  Beaufort is a city in and the county seat of Beaufort County, South Carolina, United States. Chartered in 1711, it is the second-oldest city in South Carolina, behind Charleston. The city's population was 12,361 in the 2010 census. It is located in the Hilton Head Island-Beaufort Micropolitan...
  
  , via U.S. 21
- Charleston
  Charleston, South Carolina
  Charleston is the second largest city in the U.S. state of South Carolina. It was made the county seat of Charleston County in 1901 when Charleston County was founded. The city's original name was Charles Towne in 1670, and it moved to its present location from a location on the west bank of the...
  
  , via I-26
  Interstate 26
  Interstate 26 is a nominally east–west main route of the Interstate Highway System in the Southeastern United States. I-26 runs from the junction of U.S. Route 11W and U.S. Route 23 in Kingsport, Tennessee, generally southeastward to U.S. Route 17 in Charleston, South Carolina...
- Georgetown County, via U.S. 17
- The Grand Strand
  Grand Strand
  The Grand Strand refers to a large stretch of beaches on the East Coast of the United States extending from Little River to Georgetown in the U.S. State of South Carolina. It consists of 60+ miles along an essentially uninterrupted arc of beach land, beginning around the Little River and...
  
  , via U.S. 501
- Hilton Head Island
  Hilton Head Island, South Carolina
  Hilton Head Island or Hilton Head is a resort town in Beaufort County, South Carolina, United States. It is north of Savannah, Georgia, and south of Charleston. The island gets its name from Captain William Hilton...
  
  , via U.S. 278
Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
- Corpus Christi
  Corpus Christi, Texas
  Corpus Christi is a coastal city in the South Texas region of the U.S. state of Texas. The county seat of Nueces County, it also extends into Aransas, Kleberg, and San Patricio counties. The MSA population in 2008 was 416,376. The population was 305,215 at the 2010 census making it the...
  
  , via I-37
  Interstate 37
  Interstate 37 is a intrastate Interstate Highway located within the U.S. state of Texas. The highway was first designated in 1959 as a route between Corpus Christi and San Antonio. Construction in the urban areas of Corpus Christi and San Antonio began in the 1960s and the segments of the...
- Houston
  Houston, Texas
  Houston is the fourth-largest city in the United States, and the largest city in the state of Texas. According to the 2010 U.S. Census, the city had a population of 2.1 million people within an area of . Houston is the seat of Harris County and the economic center of , which is the ...
  
  , via I-10
  Interstate 10
  Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
  
  , I-45
  Interstate 45
  Interstate 45 is an intrastate Interstate Highway located entirely within the U.S. state of Texas. It connects the cities of Dallas and Houston, continuing southeast from Houston to Galveston over the Galveston Causeway to the Gulf of Mexico...
  
  , U.S. 290, and U.S. 59
- Freeport
  Freeport, Texas
  Freeport is a city in Brazoria County, Texas within the Houston–Sugar Land–Baytown metropolitan area and is situated in Southeast Texas. As of the 2000 U.S...
  
  , Surfside Beach
  Surfside Beach, Texas
  Surfside Beach is a city in Brazoria County, Texas, United States that is situated on the Gulf of Mexico just west of Galveston Island. The city is part of the Greater Houston area. The population was 763 at the 2000 census...
  
  , and Lake Jackson
  Lake Jackson, Texas
  Lake Jackson is a city in Brazoria County, Texas within the Houston–Sugar Land–Baytown metropolitan area. As of a 2006 U.S. Census Bureau estimate, the city population was 27,614....
  
  via SH 288 and SH 36.
- Rio Grande Valley
  Rio Grande Valley
  The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...
  
  , via U.S. Highway 83 from Brownsville
  Brownsville, Texas
  Brownsville is a city in the southernmost tip of the state of Texas, in the United States. It is located on the northern bank of the Rio Grande, directly north and across the border from Matamoros, Tamaulipas, Mexico. Brownsville is the 16th largest city in the state of Texas with a population of...
  
  to McAllen
  McAllen, Texas
  McAllen is the largest city in Hidalgo County, Texas, United States. It is located at the southern tip of Texas in an area known as the Rio Grande Valley and is part of the . Its southern boundary is located about five miles from the U.S.–Mexico border and the Mexican city of Reynosa, the Rio...
  
  , U.S. Highway 281 from Pharr to Falfurrias
Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
- The Hampton Roads
  Hampton Roads
  Hampton Roads is the name for both a body of water and the Norfolk–Virginia Beach metropolitan area which surrounds it in southeastern Virginia, United States...
  
  area, via I-64
  Interstate 64
  Interstate 64 is an Interstate Highway in the Midwestern and Southeastern United States. Its western terminus is at I-70, U.S. 40, and U.S. 61 in Wentzville, Missouri. Its eastern terminus is at an interchange with I-264 and I-664 at Bowers Hill in Chesapeake, Virginia. As I-64 is concurrent with...

Highway reconstruction

When roads are undergoing construction amid heavy traffic, one lane of traffic may be blocked and another lane reversed.

Two-lane arterials

A construction worker

Construction worker

A construction worker or builder is a professional, tradesman, or labourer who directly participates in the physical construction of infrastructure.-Construction trades:...

or police officer

Police officer

A police officer is a warranted employee of a police force...

directs traffic with a sign displaying "STOP" on one side and "SLOW" on the other. The sign flips, and the other side proceeds. Traffic signals are also sometimes used, especially during bridge

Bridge

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

construction or any situation in which a lane must be closed during times when construction crews are not at work. Other cases include treating the street as a temporary one-way street in areas in which several nearby parallel streets are available as a detour for the opposing side.

Roads with four or more lanes

If road construction necessitates the complete closure of one half of a road with four or more lanes, two lanes of traffic may be shifted to the other roadway. If the road being constructed is a highway

Highway

, the used half is called a semi-highway.

Freeways and motorways

When controlled-access highway

Controlled-access highway

A controlled-access highway is a highway designed exclusively for high-speed vehicular traffic, with all traffic flow and ingress/egress regulated...

s undergo reconstruction, both sides are often reduced to one lane. In some cases, traffic may be shifted onto one half, making it a temporary two-lane freeway

Two-lane freeway

A two-lane expressway is an expressway with only one lane in each direction, and usually no median barrier. It may be built that way because of constraints, or may be intended for expansion once traffic volumes rise. The term super two is often used by roadgeeks for this type of road, but traffic...

corridor. An example of this is Interstate 10

Interstate 10

Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...

in Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, in which eastbound traffic is reduced to one lane and shifted onto the westbound half of the road. Another technique is to treat the rightmost hard shoulder as a travel lane. On a six-lane freeway (i.e., one containing three lanes in each direction), a third lane may be kept open for the busier direction, or the shoulder may be opened to allow for four lanes of traffic but with little or no shoulder space; emergency breakdown areas may be added. In these situations, temporary "YIELD" or "STOP" signs are usually posted on merge ramps on freeways, expressways, and uncontrolled roads with interchange

Interchange (road)

In the field of road transport, an interchange is a road junction that typically uses grade separation, and one or more ramps, to permit traffic on at least one highway to pass through the junction without directly crossing any other traffic stream. It differs from a standard intersection, at which...

Other situations

While these traffic plans may not necessarily be referred to as "contraflow", they share the essential feature of using lanes normally expected to carry one direction of traffic for vehicles traveling in the opposite direction.

Sporting events

At the beginning and end of major sporting events, the center turn lanes of roads around a stadium or arena may be used to accommodate event traffic. Because these lanes are typically not subject to lane control, this can be considered a limited form of contraflow reversal.

Mass transit

Contraflow bus lane

Bus lane

A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport that would be otherwise held up by traffic congestion...

s, areas in which a dedicated lane of an otherwise one way street is reversed for buses and other mass transit, exist in locations such as:

Downtown Los Angeles, CA
Downtown Los Angeles
Downtown Los Angeles is the central business district of Los Angeles, California, United States, located close to the geographic center of the metropolitan area...
Pittsburgh, PA
Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...

, Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
Through the Lincoln Tunnel
Lincoln Tunnel
The Lincoln Tunnel is a long tunnel under the Hudson River, connecting Weehawken, New Jersey and the borough of Manhattan in New York City.-History:...

between New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

and New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
Downtown Minneapolis, MN
Leeds
Leeds
Leeds is a city and metropolitan borough in West Yorkshire, England. In 2001 Leeds' main urban subdivision had a population of 443,247, while the entire city has a population of 798,800 , making it the 30th-most populous city in the European Union.Leeds is the cultural, financial and commercial...

, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
London, England
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
Edmonton, AB
Edmonton
Edmonton is the capital of the Canadian province of Alberta and is the province's second-largest city. Edmonton is located on the North Saskatchewan River and is the centre of the Edmonton Capital Region, which is surrounded by the central region of the province.The city and its census...
Downtown Portland, OR
Downtown Portland
Downtown Portland, the city center of Portland, Oregon, United States, is located on the west bank of the Willamette River. It is in the northeastern corner of the southwest section of the city and is where most of the city's high-rise buildings are found....
Boston, MA
Boston
Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...

(for the Silver Line
Silver Line (MBTA)
The Silver Line is the only bus rapid transit line currently operated by the Massachusetts Bay Transportation Authority . It operates in two sections; the first runs from Dudley Square in Roxbury to downtown Boston, Massachusetts and South Station, mostly via Washington Street, with buses...

bus)
Montreal, QC
Montreal
Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...

(Champlain Bridge
Champlain Bridge (Montreal)
The Champlain Bridge is a steel truss cantilever bridge with approach viaducts constructed of prestressed concrete beams supporting a prestressed concrete deck paved with asphalt...

)
San Juan, PR
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...
Mexico City, Mexico
Mexico City
Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...

From June 1990 to June 2002, a similar line

Montreal bus rapid transit

There was one bus rapid transit route in Montreal, Quebec, Canada in operation. It operated from 1989 to 2002 on Pie-IX Boulevard, and after it ceased operating, became a regular reserved lane rush hour service using regular bus stops as the 505 Reserved Lane Pie-IX. It is projected to return to...

existed in Montreal

Montreal

Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...

, along Pie-IX Boulevard

Pie-IX Boulevard

Pie-IX Boulevard, named after Pope Pius IX, is a major boulevard on the island of Montreal. It runs for roughly in a northwest/southeast direction between Henri Bourassa Boulevard and Notre-Dame East...

; this was indefinitely suspended after two fatalities.
Government buses use a bus-only contraflow lane on Macquarie St in Hobart

Hobart

Hobart is the state capital and most populous city of the Australian island state of Tasmania. Founded in 1804 as a penal colony,Hobart is Australia's second oldest capital city after Sydney. In 2009, the city had a greater area population of approximately 212,019. A resident of Hobart is known as...

, Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

.

Tram lanes are an extension to this system found in cities with curbside streetcar networks. For example, tram lanes in Zagreb

Zagreb

Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...

can be used only by trams, buses, and taxicabs.

Cycle lanes

In several cities, cycle lanes have been created to allow cycling in the direction opposite traffic on an otherwise one-way street. Sidewalks along one-way streets also allow for opposite direction cycling. Sidewalks along major thoroughfares in general allow 2-way bicycling regardless of motor vehicle travel side.

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.