{{two other uses||specific systems, such as the [[Autobahns of Germany]]|list of highway systems with full control of access and no cross traffic}}
A '''freeway''' is a type of [[highway]] that is designed for [[Road safety#Motorway|safer]] high-speed operation of [[motor vehicle]]s through the elimination of [[at-grade intersection]]s. This is accomplished by imposing full control of access from adjacent properties and eliminating all [[cross traffic]] with [[grade separation]]s and [[interchange (road)|interchange]]s, and no [[railroad crossing]]s. Such highways are usually [[divided highway|divided]] with at least two [[lane (road)|lane]]s in each direction. Because traffic never crosses at-grade, there are generally no [[traffic light]]s or [[stop sign]]s.
The word "freeway" first surfaced in the mid-1930s in proposals for the improvement of the [[New York City]] [[parkway]] network.[E.L. Yordan, "The 'Freeway' System Expands: Broader Roads With Grade Crossings Eliminated Are Built And Latest Designs Envision Still Greater Speed And Safety", ''[[New York Times]]'', [[24 February]] [[1935]], p. 21.] It is currently in regular use in [[Canada]], [[Taiwan]], [[Australia]], and the [[United States]].
==General characteristics==
[[Image:Los Angeles Freeway Interchange.jpg|thumb|300px|right|High-capacity [[freeway interchange]] in [[Los Angeles, California]].]]
Freeways, by definition, have no cross traffic in the form of other roads, [[railroad]]s or [[multi-use trail]]s. Elimination of cross traffic is typically achieved with grade separation using [[underpass]]es and [[overpass]]es. In addition to [[sidewalk]]/Footpaths attached to roads that cross a freeway, specialized pedestrian bridges or tunnels may also be provided. These structures enable [[pedestrian]]s and [[cyclist]]s to cross the freeway without a long detour to the nearest motor vehicle crossing. [[Movable bridge]]s are occasionally present on freeways, requiring drivers to yield to river traffic.
Access is typically provided only at interchanges, though lower-standard [[right-in/right-out]] access can be used for direct connections to side roads. In ideal cases, sophisticated interchanges allow for smooth, uninterrupted transitions between intersecting freeways. However, sometimes it is necessary to exit onto a surface road to transfer from one freeway to another.[The town of [[Breezewood, Pennsylvania]] is a notorious example in the Uunited States.] Exits are sometimes [[exit number|numbered]] to help drivers identify their desired exit.
[[Image:401atDVP.jpg|thumb|250px|[[Highway 401 (Ontario)|Highway 401]] through the [[Greater Toronto Area]] uses [[collector and express lane]]s to divide traffic.]]
[[Two-lane freeway]]s, often undivided, are sometimes built when traffic volumes are low or right-of-way is limited; they may be designed for easy conversion to one side of a four-lane freeway. Otherwise, freeways typically have at least two lanes in each direction; some busy ones can have as many as 16 lanes[Portions of the [[Downtown Connector]] in [[Atlanta, Georgia]] has eight lanes in each direction.] or up to 18 for short distances.[In [[Mississauga, Ontario]], [[Highway 401 (Ontario)|Highway 401]] uses [[local-express lanes|collector-express lanes]] for a total of 18 lanes through its intersection with [[Highway 403 (Ontario)|403]]/[[Highway 410 (Ontario)|410]] and [[Highway 427 (Ontario)|427]].] These wide freeways may use separate [[collector and express lane]]s to separate through traffic from local traffic, or special [[high-occupancy vehicle]] lanes, either as a special restriction on the innermost lane or a separate roadway, to encourage [[carpool]]ing. These HOV lanes, or roadways open to all traffic, can be [[reversible lane]]s, providing more capacity in the direction of heavy traffic, and reversing direction before traffic switches. Sometimes a [[collector/distributor road]], a shorter version of a local lane, shifts weaving between closely-spaced interchanges to a separate roadway or altogether eliminates it.
Freeways can have [[frontage road]]s, normal surface roads parallel to and on either side of the freeway, to provide access to adjacent properties. Frontage roads typically have [[one-way]] traffic flow in [[urban area]]s and two-way traffic flow in [[rural area]]s.{{citation needed}}
Except on some [[two-lane freeway]]s (and very rarely on wider freeways), a [[median (road)|median]] separates the opposite directions of traffic. This strip may be as simple as a grassy area, or may include a [[crash barrier]] such as a [[Jersey barrier]] to prevent [[head-on collision]]s.[Anonymous, "Median barriers prove their worth", ''Public Works'' 123, no. 3 (March 1992): 72-73.] On some freeways, the two carriageways are built on different alignments; this may be done to make use of available corridors in a mountainous area or to provide narrower corridors through dense [[urban area]]s.
[[Speed limit]]s are generally higher than on similar non-freeways, and are sometimes nonexistent (for instance on several [[German Autobahn]]s). Because the high speeds reduce decision time, freeways are usually equipped with a larger number of [[guide sign]]s than other roads, and the signs themselves are physically larger. In major cities, guide signs are often mounted on overpasses or overhead gantries so that drivers can see where each lane goes.
In most areas, there are public [[rest area]]s or [[service area]]s on freeways, as well as [[emergency phone]]s on the [[hard shoulder|shoulder]] at regular intervals.
===Access restrictions===
To reduce the probability that high-speed freeway traffic will have to slow down for slower same-direction traffic, access to freeways is usually limited to classes of [[motor vehicle]]s that are powerful enough to maintain a certain minimum speed. Some [[East Asia]]n countries partially restrict the use of motorcycles or ban them completely from freeways (or expressways in countries where that term is used) (see [[restrictions on motorcycle use on freeways]]).
In many areas, travelers using low-powered modes of transportation (such as [[pedestrian]]s, [[cyclist|bicyclists]], [[Equestrianism|equestrian]]s, and [[moped]] drivers) are banned at all times from freeways by default. These users are allowed on freeways in some jurisdictions, usually where freeways too often replaced (rather than supplemented) existing roads (see [[non-motorized vehicle access on freeways]]).
==Legal definitions==
===United States===
[[Image:I-80 Eastshore Fwy.jpg|thumb|250px|[[Interstate 80]] ([[Eastshore Freeway]]) in Berkeley, a typical American freeway (MUTCD definition)]]
[[Image:Montagueexpressway.jpg|thumb|250px|[[Santa Clara County Route G4]] (Montague Expressway), a typical American expressway (MUTCD definition)]]
In the United States, a ''freeway'' is defined by the federal government’s [[Manual on Uniform Traffic Control Devices]] as a divided highway with full control of access.[Section 1A.13, Paragraph 29, ''[[Manual on Uniform Traffic Control Devices]]'', 2003 ed., rev. 1.[http://mutcd.fhwa.dot.gov/HTM/2003r1/part1/part1a.htm]
] This means two things. First, adjoining property owners do not have a legal right of access, meaning that they cannot connect their lands to the highway by constructing driveways.[This part of the word's meaning was codified in 1939 at Section 23.5 of the California Streets and Highways Code.[http://caselaw.lp.findlaw.com/cacodes/shc/1-36.html]] When an existing road is converted into a freeway, all existing driveways must be removed and access to adjacent private lands must be blocked with fences or walls. Second, traffic on the highway is "free-flowing", although many non-engineers misapprehend the "free" in "freeway" to mean that such a highway must be free of charge to use. All cross-traffic (and left-turning traffic) has been relegated to overpasses or underpasses, so that there are no traffic conflicts on the main line of the highway which must be regulated by a traffic light, stop signs, or other traffic control devices. Achieving such free flow requires the construction of many bridges, tunnels, and ramp systems. The advantage of grade-separated interchanges is that freeway drivers can almost always maintain their speed at junctions since they do not need to yield to crossing traffic.
In contrast, an ''[[expressway]]'' is defined as a divided highway with partial control of access.[Section 1A.13, Paragraph 27, ''[[Manual on Uniform Traffic Control Devices]]'', 2003 ed., rev. 1.[http://mutcd.fhwa.dot.gov/HTM/2003r1/part1/part1a.htm]
] Expressways may have driveways and at-grade intersections, though these are usually less numerous than on ordinary arterial roads. In some states, however, this terms are used differently. In the State of New York, for instance, freeways are called expressways (e.g. [[Long Island Expressway]]).
This distinction was apparently first developed in 1949 by the Special Committee on Nomenclature of what is now the [[American Association of State Highway and Transportation Officials]].[American Association of State Highway Officials, ''AASHO Highway Definitions'' (Washington D.C., American Association of State Highway Officials, 1962), 1-3.] In turn, the definitions were incorporated into AASHTO's official standards book, the Manual on Uniform Traffic Control Devices, which would become the national standards book of the [[U.S. Department of Transportation]] under a 1966 federal statute. As an official government regulation, and as a reasonable exercise of the Department's authority, the Manual carries the force of law under American [[administrative law]]. The same distinction has also been codified into the statutory law of six states: [[California]],[Cal. Streets & Highways Code, Section 257.] [[Mississippi]],[Mississippi Code, Section 65-5-3, subdivisions (b) and (c).] [[Missouri]],[Missouri Revised Statutes, Section 304.010.] [[Nebraska]],[Nebraska Statutes, Sections 60-618.01 and 60-621.] [[Ohio]],[Ohio Revised Code, Section 4511.01, subdivisions (YY) and (ZZ). ] and [[Wisconsin]].[Wisconsin Statutes, Sections 59.84(1)(b) and 346.57(1)(am).]
==Effects and controversy==
[[image:traffic06.jpg|thumb|right|250px|[[Rush hour]] on [[I-45]], downtown Houston.]]
[[Image:Interstate H-1.jpg|thumb|right|500px|Interstate H-1 eastbound into Honolulu.]]
Freeways have been constructed both between urban centers and within them, making common the style of sprawling [[suburb]]an development found near most modern cities. As well as reducing travel times, the ease of driving on them [[Traffic_safety#Motorway | reduces accident rates]], though the speeds involved also tend to increase the severity and death rate of the [[collision]]s that do still happen.
Freeways have been heavily criticized by environmentalists and preservationists for the noise,[Hugo Martin, "Sounding Off On Noise: Freeways' Neighbors Struggle To Drown Out Road Racket, Experts Say The Din Creates Mental And Physical Hazards", Los Angeles Times, 20 April 2003, B1.] pollution, and economic shifts they bring. Additionally, they have also been criticized by the driving public for the inefficiency with which they handle peak hour traffic.[Sandy McCreery, "Don't just sit there, enjoy it!" ''[[New Statesman]]'', [[23 July]] [[2001]], 23.
][Martha Smilgis, "Trapped behind the wheel; clever commuters learn to live in the slow lane", ''[[Time (magazine)|Time]]'', [[20 July]] [[1987]], p. 64-65.][Gerard Coulombe, "Doing The Turnpike Crawl", ''[[New York Times]]'', [[6 July]] [[1986]], sec. CN, p. 16.]
Often, rural freeways open up vast areas to economic development, generally raising property values. But mature freeways in urban areas are quite often a source of lowered property values, contributing to the deleterious effects of [[urban blight]]. One major problem is that even with overpasses and underpasses, freeways tend to divide neighborhoods — especially impoverished ones where residents are less likely to own a car that could easily take them around the freeway.[Jeffrey Spivak, "Today's road opening represents progress, pain", ''Kansas City Star'', [[27 July]] [[1999]], sec. A, p. 1.] For these reasons, almost no new urban freeways have been built in the U.S. since 1970.
Some have even been demolished and reclaimed as [[boulevard]]s, notably in [[Portland (OR)|Portland]] ([[Harbor Drive (Portland)|Harbor Drive]]), [[San Francisco]] ([[Embarcadero Freeway]]) and [[Milwaukee]] ([[Park East Freeway]]).
Freeway opponents argue that freeway expansion is self-defeating, in that expansion will just generate more traffic. That is, even if traffic congestion is initially shifted from local streets to a new or widened freeway, people will begin to run errands and commutes to more remote locations which took too long to reach in the past. Over time, the freeway and its environs will become congested again as both the average number and distance of trips increase. This controversial idea is known as the [[induced demand]] [[hypothesis]].[Robert Cervero, "Road expansion, urban growth, and induced travel: a path analysis", ''Journal of the American Planning Association'' 69, no. 2 (Spring 2003): 145-164.][Hugo Martin, "Will More Freeways Bring More Traffic?" ''[[Los Angeles Times]]'', [[10 April]] [[2002]], sec. B, p. 1.
]
Freeway advocates argue that properly designed and maintained freeways are aesthetically pleasing, convenient, and safe, at least in comparison to the uncontrolled roads they replace or supplement, and that they expand recreation, employment and education opportunities for individuals[Drusilla Van Hengel, Joseph DiMento, and Sherry Ryan, "Equal Access? Travel Behaviour Change in the Century Freeway Corridor, Los Angeles", ''Urban Studies'' 36, no. 1 (March 1999): 547.] and open new markets to [[small business]]es.[Christy Borth, ''Mankind on the Move: The Story of Highways'' (Washington, D.C.: The Automobile Safety Foundation, 1969), 248 and 264.]
At present, freeway expansion has largely stalled in the [[United States]], due to a multitude of factors that converged in the [[1970]]s: higher [[due process]] requirements prior to taking of private [[property]], increasing land values, increasing costs for construction materials, local opposition to new freeways in urban cores, the passage of the [[National Environmental Policy Act]] (which imposed the requirement that each new project must have an [[environmental impact statement]] or report), and falling [[gas tax]] revenues as a result of the nature of the flat-cent tax (it is not automatically adjusted for inflation) and the [[tax revolt]] movement.[Brian D. Taylor, "Public perceptions, fiscal realities, and freeway planning: the California case", ''Journal of the American Planning Association'' 61, no. 1 (Winter 1995): 43-59.]
==History==
The concept of limited-access automobile highways dates back to the [[New York City]] area [[Parkway]] system, whose construction began in [[1907]]–[[1908]]; but parkways are traditionally distinguished from freeways by lower design speeds and a ban on commercial traffic. Designers elsewhere also researched similar ideas, especially in [[Germany]], where the [[Autobahn]] would become the first national freeway system.
However, in 1925, [[Italy]] was technically the first country to build a freeway-like road, which linked [[Milan]] to [[Lake Como]].[Paul Hofmann, "Taking to the Highway in Italy", ''[[New York Times]]'', 26 April 1987, 23.] It is known in Italy as the Autostrada dei Laghi.
Meanwhile, in [[Britain]], the related concept of the [[motorway]] was first proposed by Sidney Webb in a 1910 book, ''The King's Highway'', but was not formally embraced by the government until the passage of the ''Special Roads Act 1949''.[Geoffrey Hindley, ''A History of Roads'' (London: Peter Davies, 1971), 142.] In 1926, the English intellectual [[Hilaire Belloc]] recognized the necessity of grade-separated roads for "rapid and heavy traffic", but thought they would be the exception rather than the rule:
:The creation of a great network of local highways suitable for rapid and heavy traffic is impossible. Even if the wealth of the community increases, the thing would be impossible, because it would mean the destruction of such a proportion of buildings as would dislocate all social life.[Hilaire Belloc, ''The Highway and Its Vehicles'' (London: The Studio Limited, 1926), 39.]
The first long-distance rural freeway in the United States is generally considered to be the [[Pennsylvania Turnpike]], which opened on [[October 1]], [[1940]].[Phil Patton, ''The Open Road: A Celebration of the American Highway (New York: Simon & Schuster, 1986), 77.] The Turnpike was so advanced for its time that tourists even had picnics in the median (that is, after it was already open to traffic) and local [[entrepreneur]]s did a brisk business in souvenirs.[Phil Patton, "A quick way from here to there was also a frolic", ''Smithsonian'' 21, no. 7 (October 1990): 96-108.] It was designed so that straightaways could handle maximum speeds of 102 miles per hour, and curves could be taken as fast as 90.
Shortly thereafter, on [[December 30]], [[1940]], [[California]] opened its first freeway, the [[Arroyo Seco Parkway]] (now called the Pasadena Freeway) which connected [[Pasadena, California|Pasadena]] with [[Los Angeles, California|Los Angeles]].[Cecilia Rasmussen, "Behind the Wheel: Harrowing Drive on State's Oldest Freeway — Curvy, quirky 110 carries motorists between downtown Los Angeles and Pasadena", ''[[Los Angeles Times]]'', 6 November 2001, 2.] And in 1942, [[Detroit, Michigan]] opened the world's first urban depressed freeway, the [[Davison Freeway]].[http://www.autolife.umd.umich.edu/Environment/E_Casestudy/Davison.htm] Meanwhile, traffic in Los Angeles continued to deteriorate and local officials began planning the huge freeway network for which the city is now famous.[Gladwin Hill, "Traffic Chaos Spurs Los Angeles To Plan 'Freeways' On Mass Scale: Coast Metropolis, Lacking Rapid Transit System Such as New York Possesses, Maps $300,000,000 Highway Set-Up", ''[[New York Times]]'', [[13 January]] [[1947]], p. 12.]
Today, many freeways in the United States belong to the extensive [[Interstate highway]] system (most of which was completed between 1960 and 1990). Nearly all Interstate highways are freeways. The earlier [[United States highway]] system and the highway systems of [[U.S. state]]s also have many sections that are built to controlled-access standards (though these systems are mostly composed of uncontrolled roads). Only a handful of sections of the Interstate system are not freeways, such as [[Interstate 81|I-81]] as it crosses the American span of the 2-lane Thousand Islands Bridge and a segment of [[Interstate 93]] through [[Franconia Notch]], [[New Hampshire]] that is a 2-lane road with partial access control.
===Recent developments===
Besides the U.S., [[Canada]], and [[Taiwan]] have adopted the term "freeway" to describe comparable roads, and they continue to extend their freeway networks. In [[Australia]] some states such as [[Victoria_(Australia)|Victoria]] use the term freeway, and others such as [[New South Wales]] and [[Queensland]] use the term [[motorway]].
Australia has been innovative in using the newest tunneling technologies to bring freeways into its high-density [[central business district]]s ([[Sydney]] and [[Melbourne]]). In Australia, the city of [[Adelaide]] pioneered the concept of a dedicated reversible freeway. The M2 expressway runs toward the city in the morning and out of the city in the evening. Its ramps are designed so that they can double as on- or off-ramps, depending upon the time of day. Gates and electronic signage prevent motorists from driving in the wrong direction.
China already has the world's second largest network of freeway-like roads in terms of total kilometres and will probably overtake the U.S. well before 2025 {{fact}}.
Major progress has been made in making existing U.S. freeways and expressways more efficient. Inovations include the addition of [[high-occupancy vehicle lane]]s (HOV lanes) to discourage driving solo, and building new roads with [[train]] tracks down the [[Central reservation|median]] (or overhead). California's [[Caltrans]] has been very innovative in squeezing HOVs into limited right-of-way (by elevating them), and in building special HOV-only ramps so that HOVs can switch freeways or exit the freeway without having to merge across regular traffic. Many states have added truck-only ramps or lanes on heavily congested routes, so that cars need not weave around slow-moving big rigs.
[[Intelligent transportation system]]s (ITS) are also increasingly used, with [[camera]]s to monitor and direct traffic, so that [[police]], [[fire brigade|fire]], [[ambulance]], [[tow truck|tow]], or other assistance [[vehicle]]s can be [[dispatch]]ed as soon as there is a problem, and to warn [[driving|drivers]] via [[variable message signs]], [[radio]], [[television]], and [[World Wide Web|the Web]] to avoid problem areas. Research has been underway for many years on how to partly [[automate]] cars by making [[smart road]]s with such things as buried [[magnet]]s to guide [[sensor]]-equipped vehicles, with on-board [[Global Positioning System|GPS]] to determine location, direction, and destination. While these systems may eventually be used on surface streets as well, they are most [[practical]] in a freeway setting.
====Public-private partnerships in the United States====
Until the late 1990s, funding of construction and maintenance of the Interstate Highway System was by the national gasoline tax. Additionally, the original [[Highway Act]] of 1956 prohibited states from collecting tolls on Interstate-funded expressways. As more miles of expressways were completed, the cost of maintaining the infrastructure increased dramatically. A major issue that has slowed new expressway constructing in America has been the application of highway funds to maintaining and repairing existing infrastructure. Most of the expressways in America are near or have exceeded their designed life span, which necessitates replacing of bridges and overpasses and reconstruction of the driving surfaces on many expressways nationwide.
To address the issue of lack of funding for new expressways and maintenance of existing roads, legislation enacted in 1998 gives states greater flexibility in funding major highway projects. Specifically the legislation, known as TEA-21 in official documents, authorizes states to add tolls to Interstate-funded expressways. Additionally, it gave states the latitude to enter into public-private partnership [[P3]] arrangements to facilitate expansion and maintenance of the expressway network. [[Texas]], [[Florida]], [[Virginia]], and [[California]] quickly took advantage of the TEA-21 legislation and began on massive projects to expand their respective states' expressway networks, complementing existing interstate expressways with privately funded and operated toll expressways. In 2004, [[Illinois]] sealed a $1.8 billion deal with [[Macquarie Infrastructure Group]] and Cintras to operate the [[Chicago Skyway]] for 99 years. In a similar P3 arrangmenet in [[Indiana]], the Cintras-Macquarie joint venture assumed responsibility for the [[Indiana East-West Toll Road]] for 75 years on June 30, 2006 in a $3.8 billion deal, known as [[Major Moves]]. As of late 2006, [[Pennsylvania]] is actively pursuing the P3 toll road concept, but still has to clear challenges in the state legislature before such a arrangements can be implemented on the [[Pennsylvania Turnpike]]. Meanwhile in [[New York]] and [[Massachusetts]], the respective state public authorities that operate the [[New York State Thruway]] and [[Massachusetts Turnpike]] have generated enough revenue to assume maintenance of other expressways beyond the roads on which tolls are collected. The [[Massachusetts Turnpike Authority]] provided more than 50 percent of the funding to complete the [[Big Dig]] project in Boston, and later assumed responsibility for operating the Central Artery, the [[Sumner Tunnel]], and the [[Callahan Tunnel]] following the project's completion in 2005.
As federal funding dries up for expanding and maintaing America's expressway network, states are looking to innovative solutions using a combination of state and federal funding, toll collection through public authorities, and private sector investment.
In the United States, a few short privatized [[toll road|tolled]] freeways have also been built by private companies with mixed success.
==References==
{{types of road}}
==Gallery of freeways around the world==
Image:TullamarineFwy.jpg|The "Sound Tube", [[CityLink]] Tollway, [[Melbourne]], [[Victoria (Australia)|Victoria]], [[Australia]].
Image:Autopista-Central-2.jpg|Autopista Central, [[Santiago, Chile]].
Image:AutopistaLibertadores.JPG|Autopista Los Libertadores, (International Freeway) [[Santiago, Chile]]
Image:Queensway east of Riverside Drive Ottawa.jpg|[[Highway 417 (Ontario)|Highway 417]] (The [[Queensway (Ottawa)|Queensway]]) in [[Ottawa, Ontario|Ottawa]], [[Ontario]]
Image:376 east.jpg|[[Interstate 376]] eastbound in downtown [[Pittsburgh, Pennsylvania|Pittsburgh]], [[Pennsylvania]]
Image:Motorvag - bild.jpg|Europeway E6 E20 in southwest [[Sweden]] in [[Varberg]]
Image:Old_Autobahn_DE.jpg|An older [[Germany|German]] [[Autobahn]] without an emergency lane
Image:Lowry_Hill_Tunnel.jpg|[[Interstate 94]] entering the Lowry Hill Tunnel in [[Minneapolis, Minnesota|Minneapolis]], [[Minnesota]]
Image:Near Kamshet 2 tunnel on Mumbai Pune Expressway.JPG|Near Kamshet 2 tunnel on the 6-lane [[Mumbai-Pune Expressway]]
Image:Highway1-cassiar-southbound.jpg|The [[British Columbia provincial highway 1|British Columbia portion of the Trans Canada Highway]] in [[Vancouver]], [[British Columbia]].
Image:Alessandria-L'autostrada_A-26-tratto_appenninico.jpg|The [[Italy|Italian]] [[Autostrada]] A26 while it enters a tunnel crossing northern [[Apennines]]
[[Category:highways with full control of access and no cross traffic| ]]
[[Category:Limited-access roads| ]]
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