Information AboutFreeway |
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in Los Angeles, California .]] A freeway (also ''superhighway'', '' Expressway '' or '' Motorway '' as further explained below) is a multi- Lane Highway ( Road ) designed for high-speed travel by large numbers of Vehicle s. Freeways have no Traffic Light s, Stop Sign s, or other regulations requiring vehicles to stop for cross-traffic. In general Design features Freeways have high Speed Limit s (usually 65-80 mph (100-130 km/h) in rural areas and 50-65 mph (80-100 km/h) in urban areas) and multiple lanes for travel in each direction. The number of lanes may vary from four or six in rural areas to as high as sixteen or eighteen in certain Global Cities . A median (originally "medial strip"Victor H. Bernstein, "Safer Motor Roads: New Construction Principles Introduced On Modern Highways To Cut Accidents," '' New York Times '', 1 December 1935 , 21.) or Central Reservation separates lanes with opposing traffic flow. Separation may be achieved through distance or through the use of high Crash Barrier s like cable barriers and Jersey Barrier s.Anonymous, "Median barriers prove their worth," ''Public Works'' 123, no. 3 (March 1992): 72-73. Crossroads are bypassed by grade (height) separation using Underpass es and Overpass es. In addition to the Sidewalk s attached to roads that go over or under a freeway, specialized pedestrian bridges or underground tunnels may also be provided. These structures enable pedestrians and cyclists to cross the freeway without a long detour to the nearest crossroad. The number of freeway entrances and exits is limited. They are designed with special on-ramps and off-ramps to minimize disruption of traffic flow as vehicles enter or exit. In some countries, the exits are numbered. Exit numbering may be by mile or kilometre or in a simple, sequential fashion. In ideal cases, sophisticated Interchange s with elaborate Ramp systems can allow smooth, uninterrupted transitions between freeways. However, sometimes it is necessary to exit and navigate at-grade intersections to transfer from one freeway to another. Because the high speeds reduce decision time, freeways usually have more and larger Traffic Sign s than other roads. In major cities, especially on freeways six lanes in width or wider, guide signs are mounted on overpasses or overhead gantries so that drivers can see where each lane goes. Some countries prefer to use a special icon for freeways, while others simply post "Freeway Entrance" and "Begin Freeway" signs. A problem with freeways is that Head-on Collision s caused by wrong-way drivers are often severe. Special signage and lane markings are used to discourage drivers from going the wrong way. Gallery of design features =Signage for entering the freeway Image:Beginfreewaysign.jpg|American "begin freeway" sign Image:Freewayentrancesign.jpg|California on-ramp sign Image:Autorouteentrancesign.jpg|Swiss on-ramp and "begin freeway" sign =Signage for leaving the freeway Image:Endfreewaysign.jpg|American "freeway ends" warning sign Image:SR 429 north exit 33.jpg|American Numbered Exit off-ramp sign Image:Autorouteexitsign.jpg|Swiss end of freeway/off-ramp sign =Signage for Navigation Image:Americanguidesignage.jpg|American guide signs Image:I-4 east exits 111A-B.jpg|American Numbered Exit guide sign Image:Quebec exit number.jpg| Quebec guide signs Image:PRC Expressway.jpg|China guide signs Image:Europeanguidesignage.jpg|Swiss guide signs Image:AutopistaVespucioSurantesdeRuta5.JPG|Chilean guide signs Image:On the Dhahran-Al Khobar Highway.jpg|Saudi Arabian guide signs Image:Freeway_Argentina.jpg|Guide sign in Buenos Aires, Argentina Image:Svensk motorvägsavfart, Trafikplats Hurva.jpg|Swedish Numbered Exit guide sign =Grade separations Image:Sandhillroadoverpass.jpg|American freeway overpass Image:Highway13highway24underpass.jpg|American freeway underpass =Measures to prevent wrong way drivers Image:Californiaofframpwrongwaysignage.jpg|Used by some U.S. states at freeway ends and off-ramps Access restrictions To minimize Accident s, access to freeways is usually limited to vehicles capable of consistently maintaining a high speed, like Automobile s, Truck s, Motorcycle s, Van s, and Bus es. Pedestrian s, Bicyclist s, slow-moving vehicles, Horse s, horse-drawn vehicles, and anything else that might obstruct fast-moving vehicles are all prohibited; however some freeways allow non-motor vehicles (e.g., bicycles) (see Non-motorized Vehicle Access On Freeways for more info). Motorcycle restrictions in East Asia Even though most freeways allow motorcycles with sufficient speeds, certain East Asian freeways have additional restrictions upon motorcycles, frequently due to so-called safety concerns. Certain opponents of these motorcycle restrictions argue that slower surface roads with intersections are probably more dangerous for motorcycles. In Mainland China , two-wheel motorcycles driven on the freeways may not carry passengers. A vehicle must be capable of maintaining 70 km/h to be driven on the freeways. In Taiwan , motorcycles, unless used for certain police purposes, remained prohibited from the freeways due to some safety concerns explained at the web site of the Taiwan Area National Freeway Bureau in Chinese (with counter arguments by opponents in parentheses below): #Taiwanese freeways have no room for motorcycle lanes. Sharing any lanes with cars and large vehicles would be very dangerous. (Vehicles traveling at the same speed would ''not'' collide.) #Motorcycles are much less protected than cars, so any accident would be much worse, especially when frequent interchanges with complex traffic flows would increase the dangers to motorcycles. (As most traffic accidents and crashes occur in intersections, surface roads tend to be even more dangerous for motorcycles despite common slower speeds.) #Taiwanese motorcyclists may not be patient, so should they squeeze between other vehicles, dangers would arise and traffic flow would be disturbed. (Proper safety edication for all should reduce the problems.) #The freeway traffic volume is over capacity and needs better management to relieve traffic. Allowing motorcycles would worsen traffic. (Solo car drivers switching to motorcycles should reduce traffic congestion.) As of now, the Taiwanese government plans not to allow motorcycles on freeways despite controversies. In Japan , a motorcycle must have an engine displacement of more than 125 cubic centimeters to be driven on the freeways. Two-wheel motorcycles were not allowed to carry passengers on the freeways, but a legal amendment on 1 April 2005 has partially lifted the ban. A person aged at least 20 with a motorcycle Driver License for at least 3 years may now carry a passenger on a two-wheel motorcycle on a freeway, but some segments of the Shuto Expressway still prohibits passengers on two-wheel motorcycles. A motorcycle with a sidecar may carry a passenger on the freeways. Ancillary facilities In most parts of the world, there are public Rest Area s on freeways and expressways as well as other types of highways. In some U.S. states, public rest areas are located almost exclusively on freeways or expressways (since only those routes carry the high traffic necessary to justify the area's maintenance cost). Nomenclature in English-speaking countries ''Freeway'' is the term used in most of the United States and parts of Australia , mostly Victoria , South Australia and Western Australia . The United Kingdom , Republic Of Ireland , New Zealand and other Commonwealth countries prefer '' Motorway ''; most of Canada uses '' Expressway '', or ''freeway'', but the provinces of Quebec and New Brunswick use '' Autoroute ''. Some RIRO Expressway s have at-grade intersections. Some commentators consider them to be freeways because they have design speeds of 65 mph or higher. However, others argue that RIRO expressways lack complete-controlled access since existing private businesses are allowed to retain their entrances and thus should not be classified as true freeways. Australia In Australia freeways are named as either ''freeway'' or ''motorway'', although in New South Wales some freeways are called ''expressways''. Tollways are not explicitly named, that is, ''Toll'' is appended to the designation. Tolls are usually collected at toll booths or by Electronic Tolling Technology (first used in Melbourne , Australia "E-Tag" on CityLink ). Ausway ( Melway ) describes a freeway as: ''Those roads having full access control and grade separated intersections, with the primary function of servicing high volume traffic movements.'' Most freeways are between two and five lanes each way depending on the importance of the freeway. They are generally upgraded when traffic demand exceeds the infrastructure available. Roads with partial access control or no access control, of similar size and traffic volume, are given the name Highway . Canada In Canada, there does not appear to be a national standard for nomenclature, although ''freeway'' appears to be winning out except in Ontario where ''expressway'' or ''highway'' is used, and in Quebec where they are called '' Autoroute s'' (French for 'expressway'). In Ontario , while the definitions of ''freeway'' and ''expressway'' are consistent with that of the United States, ''highway'' is used far more often than ''freeway'', especially inside the Greater Toronto Area . While this has caused some confusion because the province applies "highway" (The King's Highway) to principal roads in its network, whether freeway or non-freeway, it is usually resolved simply by using the 400-series Number to distinguish the freeway. Nonetheless, outside of the GTA, the 400-series numbering does not entirely solve the problem as there are non 400-series freeways built to similar standards such as the Conestoga Parkway (which includes sections of Highways 7 , 8 and 85 , including a long 7/8 multiplex). The only freeway officially labelled as such is the Macdonald-Cartier Freeway but it is usually known as Highway 401 or "the 401". It is not unusual for Ontario residents to refer to a numbered freeway as ''The (Number)'' versus ''Number (Number)'' for non-freeway routes. Several roads labelled ''expressways'' in the Municipal Network are actually fully controlled-access freeways such as the Gardiner Expressway and Spadina Expressway (later renamed Allen Road). near downtown Montréal .]] Other provinces use varying rules in their official road designations. Prince Edward Island and the territories do not have freeways. United Kingdom In the UK the term ''motorway'' has specific legal meanings (simply, a "special status" road). Although the term ''expressway'' and ''parkway'' are sometimes used, they amount to little more than street names, with ''motorway'' the only term officially recognised. UK motorways are engineered to some of the highest standards in the world, with almost all motorways having a full-width hard shoulder (breakdown lane), full grade-separated interchanges with long on/off ramps and a barriered central reservation (the term "median strip" is unknown in British English ). All UK motorways have an "M" prefix (e.g. M1) or, where an "A" road has been upgraded to motorway status, an "M" suffix in brackets (e.g. A1(M)). Because the term ''motorway'' refers to the legal status of the road rather than the standards to which it is built, occasionally quirks are sometimes thrown up, such as the Walton Summit Motorway in Lancashire, England, which is a very short section linking a motorway Roundabout with a standard non-motorway road. Although it has the "special status" of motorway, it has just one lane in each direction with no central reservation. This oddity is also the only motorway in the UK with no number. There are very many roads in the UK which have achieved or almost achieved motorway standard (mostly "A"-prefixed primary routes) but have not been designated motorways. Examples include the A27 in Hampshire , the A34 in Berkshire and many sections of the A1 throughout England and Scotland . United States General definitions In the United States Of America , a ''freeway'' (or ''controlled-access road'') is defined by American Civil Engineer s as a divided highway with full control of access. 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. 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. However, because freeway drivers do not have to react to unpredictable cross-traffic, they can generally drive at higher speeds than on expressways. In contrast, an ''expressway'' (or ''limited-access road'') is defined as a divided highway with partial control of access. Expressways may have driveways connecting to adjacent properties, although the trend over time has been to minimize driveways when possible. Expressways also may have at-grade intersections, though these tend to be spaced farther apart than on most arterial roads. In urban areas, expressway intersections are usually controlled by traffic lights, but in many rural areas, cross-traffic is governed only by stop signs, and there are no restrictions on through traffic. Vehicles crossing an expressway at rural intersections must race across four lanes with vehicles coming at them from both directions at 45 mph (70 km/h). Thus, expressways are more dangerous than freeways and cannot carry traffic as efficiently as a freeway. This distinction was apparently developed first in California. To remedy massive confusion among transportation officials from different parts of the country, the , which would become the national standard book of the U.S. Department Of Transportation under a 1966 federal statute.Section 1A.13, Manual on Uniform Traffic Control Devices, 2003 ed. {Link without Title} As an official government regulation, and as a reasonable exercise of the Department's authority, the Manual carries the force of law (see ,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). Exceptions However, the distinction between these two terms is not universal. In several states that built freeways very early on (including Connecticut , Illinois , Massachusetts , New Jersey , New York , Pennsylvania , and Rhode Island ), the terms ''expressway'' and ''freeway'' have the same meaning, and usually ''expressway'' or just ''highway'', an older usage, is preferred. In the New York metro area, the term ''expressway'' officially refers to a limited-access highway which large trucks are permitted to drive on, while many other limited- or controlled-access roads are designated ''parkways'', and are for passenger car use only. In New Jersey and Pennsylvania, newer roads are often officially styled ''freeways'', where older roads retain the title ''expressway''. These are also states which have toll roads, and therefore the distinction is made between a tollway (or ''turnpike'') and a freeway, the latter not costing toll. According to some residents of these states, an "expressway" is the general category, and then, depending on whether the expressway is toll or free, it may be either a tollway or a freeway. In Florida , an ''expressway'' is defined as a limited-access Toll Road , while a ''freeway'' is any other limited- or controlled-access road which costs no money to travel on. Frequently, in the Midwest and the South, neither "freeway" nor "expressway" is commonly used, and the preferred term is ''interstate'', even in cases where the expressway might not have been designated an Interstate Highway . In the rest of the country, ''freeway'' is the usual term; however, the distinction between freeways and expressways is not always as clear or well-understood as it is in California , which has many of both kinds of highway. Nomenclature (worldwide)
Construction issues Freeways have been constructed both between urban centres 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 reduces accident rates, though the speeds involved also tend to increase the severity and death rate of the Collision s (or Crash es) that do still happen. Frontage roads is a major urban freeway in the San Francisco Bay Area (seen here near Berkeley, California ). The frontage road on the far right typically becomes just as congested as the main freeway.]] Because abutters do not have the right of access that they would have for an ordinary public road, the authority undertaking construction of a freeway is frequently required to provide alternate means of access to those landowners. This is frequently accomplished, in areas lacking a dense surface street network, by construction of two uncontrolled roads parallel to and on either side of the freeway, known as Frontage Road s. These often are designed with one-way traffic flow, but not always. In Texas , where this pattern is perhaps at its zenith, such roads are frequently constructed in anticipation of a future freeway corridor, as many as ten years in advance, in order to influence development patterns on the adjoining land. Frontage roads are also often constructed in more densely-developed areas as a means to provide convenient direct access to and from the parallel freeway while minimizing the need for interchanges at every major cross street. However, some traffic studies have indicated that this particular type of access and the development that ensues generally causes significant traffic congestion and disrupts flows along major freeways. These studies prompted concern for TxDOT, which formally adopted a major shift in frontage road policy (2002) by stating that ''no new frontage roads will be built along any proposed limited-access freeways'', thus ending a long-standing pattern of freeway-induced development in Texas. Access issues will continue to be assessed on a local basis, and frontage roads could still be constructed if warranted by traffic studies. Collector lanes through the Greater Toronto Area uses a collector-express system to divide traffic.]] The successor to frontage/service roads in urban freeways is the Collector-express system; the lanes accessing (often closely-spaced) interchange ramps are known as Collector/distributor Road s. Newer suburban freeways are designed with interchanges spaced far apart such that neither service roads or collector lanes are needed. History The concept of limited-access automobile highways dates back to the New York City area Parkway system, which began to be constructed in 1907 – 1908 . Designers elsewhere also researched these ideas, especially in Germany , where the Autobahn became the first national freeway system. In 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 term "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," ''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 '', 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). Almost all interstates are freeways, but the earlier United States Highway system and the highway systems of U.S. State s also have many sections that are limited-access (though these systems are mostly composed of uncontrolled roads). Only a handful of sections of the Interstate system are not freeways, such as I-81 as it crosses the American span of the 2-lane Thousand Islands Bridge. Controversy on I-45 , downtown Houston.]] Freeways have been heavily criticized by environmentalists and preservationists for the noise, 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 '', 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 in Manhattan, a quintessential urban freeway in need of expansion and reconstruction. The outcome of the study basically charged that the current elevated highway be replaced with a new, at-grade boulevard with integrated pedestrian facilities. This case study is suggested as a precedent for areas where a typical, elevated urban freeway is not desirable and/or effective at handling impacted traffic. Some 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 is the debated '', 10 April 2002 , sec. B, p. 1. Pro-freeway advocates point out that properly designed and maintained freeways are aesthetically pleasing, convenient, and safe, at least in comparison to the uncontrolled roads they replace or supplement. Freeways expand recreation, employment and education opportunities for individualsDrusilla 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.Borth, 248 and 264. And for many, uncongested freeways are fun to drive. At present, freeway expansion has largely stalled in the 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. Recent developments Outside the U.S., many countries continue to rapidly expand their freeway networks. Examples include: Australia , Canada , Chile , China , France , India , Israel , Mexico , Malaysia , Pakistan , the Philippines , Spain and Taiwan . Australia and France in particular have been innovative in using the newest tunneling technologies to bring freeways into high-density downtowns ( Sydney and Melbourne ) and historic rural areas ( Versailles ). China already has the world's second largest freeway network in terms of total kilometers and will probably overtake the U.S. well before the end of the 21st century. 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. Meanwhile, major progress has been made in making existing U.S. freeways and expressways more efficient. Experiments include the addition of High-occupancy Vehicle Lane s (HOV lanes) to discourage driving solo, and building new roads with Train tracks down the 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 , Ambulance , Tow , or other assistance Vehicle s can be Dispatch ed as soon as there is a problem, and to warn Drivers via Variable Message Signs , Radio , Television , and 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 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. In the United States, a few short privatized Tolled freeways have also been built by private companies with mixed success. Freeways around the world Image:freeway.jpg| Interstate 405 in Irvine, California , with an Interchange in the foreground Image:TullamarineFwy.jpg|The " Sound Tube ", CityLink Freeway, Melbourne , Victoria, Australia. Image:Autopista-Central-2.jpg|Autopista Central, Santiago, Chile . Image:AutopistaLibertadores.JPG|Autopista Los Libertadores, (International Freeway) Santiago, Chile Image:DSCN4922.JPG| US-75 Central Expressway southbound in Dallas ,Texas Image:376 east.jpg|Interstate 376 eastbound in downtown Pittsburgh Image:Swedish_Motorway_Varberg.jpg|Europeway E6 E20 in southwest Sweden in Varberg Image:Old_Autobahn_DE.jpg|Two-lane German Autobahn without emergency lane Image:Autoroute Ville-Marie.jpg| Autoroute Ville-Marie near downtown Montréal . Image:Lowry_Hill_Tunnel.jpg| Interstate 94 entering the Lowry Hill Tunnel in Minneapolis . References See also
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