Controlled-access highway facts for kids

A motorway in Sweden

A freeway in Canada

A controlled-access highway, known by various terms worldwide, including autobahn, autopista, autoroute, autostrada, freeway, motorway and sometimes expressway, is a highway designed and built specifically for high-speed vehicular traffic. Its primary purpose is to provide an unhindered flow of traffic, with no traffic signals, intersections or property access. Access is provided by slip roads or ramps, which allow for acceleration and deceleration between the highway and arterial thoroughfares and collector roads.

The opposing directions of travel are separated in some form, either by a strip of grass or boulders, or by a wooden, metal or concrete barrier, referred to as a median or central reservation. A controlled-access highway is free of any at-grade crossings with other roads, railways or pedestrian paths; overpasses and underpasses provide access across the highway.

Germany pioneered the controlled-access highway (then referred to as a Dual Highway) following the First World War and rapidly assembled a sprawling network of Autobahns in anticipation of their use in the war effort. Italy followed shortly thereafter, opening its first Autopista in 1925.

In North America, a similar concept, known as a parkway, was developed on Long Island. These parkways did not perform the same function as a modern highway, but were divided and designed specifically for automobiles. Ontario and Pennsylvania opened the first North American freeways in 1940. Britain, heavily influenced by the railroad, did not build its first motorway until the mid-1950s.

Today, most industrialized nations feature an extensive network of freeways or motorways. Many have a national-level system of route numbering. The highway has brought with it the ability to access almost any part of the world with comfort and speed, but has mired controversy over the pollution, degradation to farmland and urban sprawl with which it has been associated.

History
Environmental effects
Images for kids
See also

History

Edward Murray Bassett

The word freeway was coined by the "Father of American Zoning," Edward M. Bassett, in an influential article published in February 1930. Bassett argued that roads should be classified into three basic types: highways, parkways, and freeways.

Modern controlled-access highways originated in the early 1920s in response to the rapidly increasing use of the automobile, the demand for faster movement between cities and as a consequence of improvements in paving processes, techniques and materials. These original high-speed roads were referred to as "dual highways" and, while divided, bore little resemblance to the highways of today.

The first dual highway in the world opened in 1921 between Milan and Varese and now forms parts of the A8 and A9 motorways. This highway, while divided, featured only one lane in each direction and no interchanges. Shortly thereafter, in 1924, the Bronx River Parkway was opened to traffic.

The Bronx River Parkway was the first road in North America to utilize a median strip to separate the opposing lanes, to be constructed through a park and where intersecting streets crossed over bridges.

Hokkaidō Expressway in Japan

These kinds of highways have four lanes or more. They carry many vehicles. They have no traffic-lights or ground level intersections. All roads crossing the highway go over a bridge or a tunnel. Ramps connect the highways to smaller roads and other highways. The place where highways meet these roads are called junctions or interchanges. Places where cars can leave or enter the motorway are called exits. Many freeways do not allow slower traffic, such as bicycles and pedestrians, to enter them.

Most controlled-access highways are divided with at least two lanes going each way, but they can be as wide as four lanes in large cities.

Environmental effects

Controlled-access highways have been constructed both between urban centres and within them, leading to the sprawling suburban development found near most modern cities. They ideally serve to reduce travel times and accident rates, though the higher speeds have increased the severity and death rates of the collisions that do occur.

Highways have been heavily criticized by environmentalists, urbanists, and preservationists for the noise, pollution, and economic shifts they bring. Additionally, they have been criticized by the driving public for the inefficiency with which they handle peak hour traffic.

The "Downtown Connector" (I-75 and I-85) in Atlanta, Georgia, United States, during rush hour

Construction of urban freeways for the U.S. Interstate Highway System, which began in the late 1950s, led to the demolition of thousands of city blocks, and the dislocation of many more thousands of people. The citizens of many inner city areas responded with the freeway and expressway revolts. Through the study of Washington's response, it can be shown that the most effective changes came not from executive or legislative action, but instead from policy implementation. One of the foremost rationales for the creation of the U.S. Department of Transportation (DOT) was that an agency was needed to mediate between the conflicting interests of interstates and cities. Initially, these policies came as regulation of the state highway departments. Over time, DOT officials re-focused highway building from a national level to the local scale. With this shift of perspective came an encouragement for alternative transportation, and locally based planning agencies.

Often, rural highways open up vast areas to economic development and municipal services, generally raising property values. In contrast to this, above-grade highways in urban areas are often a source of lowered property values, contributing to urban decay.

Motorway E6 in Scania

Interstate 94 entering the Lowry Hill Tunnel in Minneapolis, Minnesota, US

Beginning in the early 1970s, the U.S. Congress identified freeways and other urban highways as responsible for most of the noise exposure of the U.S. population. Subsequently, computer models were developed to analyze freeway noise and aid in their design to help minimize noise exposure.

Some cities have implemented freeway removal policies in which freeways have even been demolished and reclaimed as boulevards or parks, notably in Portland (Harbor Drive), New York City (West Side Highway), Boston (Central Artery), San Francisco (Embarcadero Freeway) and Milwaukee (Park East Freeway).

An alternative to surface or above ground freeway construction has been the construction of underground urban freeways using tunnelling technologies. This has been extremely successful in the Australian cities of Sydney (which has five such freeways) and Melbourne (which has two such freeways). This has had the benefit of removing traffic from surface roads and in the case of Melbourne's Eastlink Motorway, has helped preserve an ecologically sensitive area from destruction.

Other Australian cities face similar problems (lack of available land, cost of home acquisition, aesthetic problems, and community opposition). Brisbane, which also has to contend with physical boundaries (the river) and heavy population increases, has embraced underground tunnel freeways. There are currently three under active development, one of which (the North-South Bypass Tunnel) is currently under construction. All of the planned tunnels include provisions for public transport, whether underground or in reclaimed space on the surface.

Images for kids

The interchange between US 131, M-6 and 68th Street in Cutlerville, Michigan, United States, shows many of the features of controlled-access highways: entry and exit ramps, median strips for opposing traffic, no at-grade intersections and no direct access to properties.
Typical overhead signage on Ontario's King's Highway network featuring an airport pictogram, distances to upcoming interchanges, and lane guidance.
An aerial view of Finnish national road 3 (E12), a motorway between Tampere and Helsinki in Finland
Highway interchange between the Dolphin Expressway and Palmetto Expressway in Greater Miami, Florida, United States
Highway 401 in Southern Ontario, Canada. An example of a collector-express freeway design, the route features four carriageways through Toronto.
The A10 near Orléans, France, showing hard shoulder and emergency telephone. The broken demarcation line for the hard shoulder is specific to France, and serves as a safety reference mark for drivers: the advisory distance from the vehicle ahead is two dashes minimum.
De Lucht Rest Area on the Dutch A2 - A typical rest area in the Netherlands with services (fuel, refreshments and toilets). The only access is via the highway that it serves.
The Belgrade Urban Motorway, constructed between 1970 and 1977, required demolitions of streets and houses, characteristic of urban motorways. In Novi Beograd, the motorway path was already laid out, requiring no demolitions.
The High Five Interchange in Dallas, Texas, a stack interchange with elevated entrance and exit ramps connecting Interstate 635 and U.S. Route 75
An aerial view of the Lakalaiva interchange in the Tampere Ring Road between the Highway 3 (E12) and Highway 9 (E63) near city of Tampere
Highway lighting can have a negative influence on those living close to the freeway. High-mast lighting is an alternative as it concentrates the light on the road, but the tall structures can also lead to a NIMBY effect. Seen here is Ontario Highway 401 through suburban Toronto.
Tunnel on the A1 Motorway in Greece
Signage on the M6 near Kinnegad in Ireland. The pictogram of a dual carriageway traversed by an overpass is used in many European countries to indicate the start of motorway regulations. In this case the appropriate motorway number is shown and in accordance with Irish practice a continuous yellow line indicates a motorway rather than a high-quality dual carriageway (HQDC).
Sign on a Swiss Autostrada (A2/E35 near Lugano, Switzerland)
Trans-African Highways
Algerian highways network
The Addis Ababa–Adama Expressway
Map of Moroccan highways and expressways
PanAmerican Highway
Leeward Highway, Turks and Caicos Islands, UK
Map of Mexican Autopista network
Asian highways
Highways of the Caucasus
The Delaram-Zaranj Highway at the Iran-Afghanistan border
N1, connecting Dhaka and Chittagong
The Bali Mandara Toll Road, in Bali, Indonesia
Tehran-Karaj highway
Highway between Erbil and Mosul
Highway 431 near Rishon LeZion
Ayalon Highway near Rokach Interchange
Map of Japanese Expressways with numbering scheme
Sungai Long exit, Kajang Dispersal Link Expressway, Selangor Malaysia
National highways of Pakistan, showing Motorways and Expressways
Map of expressways in Luzon
Highway 60 passing through the Hijaz Mountains
The Bukit Timah Expressway in Singapore
The Southern Expressway (E01) in Sri Lanka
National highways in Syria
M39 Highway near Jomboy
Expressway network of Vietnam
Current map of Albanian motorways
Bulgarian motorway network
Map of Greece's motorway network
Motorways in the Netherlands
A1/A2/A4 Interchange at Miladinovci, North Macedonia
Swiss highway network
Motorways in Turkey
The M25 Motorway near Heathrow Airport
East–West Highway near Oran
Autoroute Est-Ouest, near Ghomri, Relizane Province
Autoroute A2 near Bouira
Autoroute Nord-Sud near Médéa
The first expressway in Morocco - A1 Casablanca–Rabat
Toll station at Bouznika
A3 Casablanca–Agadir
Rodovia dos Imigrantes, São Paulo
The Rio–Niterói Bridge, officially part of the federal BR-101 highway; a landmark of Rio de Janeiro
BR-116 in Ceará
Mezcala Bridge on Highway 95 in Mexico
Tehuantepec, Baja California
Mexican Federal Highway 1 Junction in San Ignacio, Baja California Sur
Eastbound Fed. 2 just outside Altar, Sonora, after a summer rain
The expressway crosses the Yangtze River over the Jiangyin Suspension Bridge
G106, Jingkai Expressway section in southern Beijing
G6 Expressway at the interchange with the Fifth Ring Road in northern Beijing
Signs using the new numbering system as seen on China National Expressway 1 in Tianjin
North Lantau Highway on Lantau Island
Tolo Highway in Ma Liu Shui
Fanling Highway in Sheung Shui
North West Tsing Yi Interchange near Tsing Ma Bridge (Lantau Link)
Section of the Delhi Gurgaon Expressway
The Mumbai-Pune Expressway
The Delhi-Meerut Expressway
A section of Noida–Greater Noida Expressway
Many Japanese expressways go through the steep mountains.
A group of green-colored directional signs on a Japanese expressway
Toll gates are placed at most of the entrances and exits of Japanese expressways.
Aerial view of Toyota Junction, connecting Tomei Expressway and Ise-Wangan Expressway
The Shutoko C1 route forms a loop of the center of Tokyo
The motorway M-2 passes through the Salt Range mountains
M-1 motorway westbound towards Peshawar
M-1 Peshawar Toll Plaza
M-15 at Mansehra
The Makran Coastal Highway (N10) passing through Balochistan
A portion of North Luzon Expressway in Guiguinto, Bulacan
South Luzon Expressway in the Philippines
Approaching Seoul from Incheon Airport
Seohae Bridge
Airport Town Square junction
Incheon Bridge Toll Gate
Freeway 1 in New Taipei City
Taichung section
Freeway entrance
A Motorway interchange in Makkasan, Bangkok
Srinagarindra Interchange head to Rama IX Road
Long Thanh bridge
Cho Dem - Ben Luc Viaduct of Ho Chi Minh City - Trung Luong Expressway
Lien Khuong - Prenn Pass Expressway
A1 Nation's Highway in Northern Albania connecting Albania with Kosovo.
Krraba Tunnel on the A3 Tirana, Elbasan, Albania
A2 Fier - Vlore known as the Independence Highway
Brenner Autobahn near Innsbruck
A22 Donauuferautobahn, near the exit Floridsdorfer Brücke
A1 motorway, exit Bijača, towards the Zvirovići interchange
Mahovljanska interchange
A1 motorway
Valtatie 1 near Halikko
Ring I (Kehä I) in Pohjois-Haaga, a northern district of Helsinki.
Cross between A430 motorway and A43 motorway
Toll barrier in Hordain (south of Hordain), on autoroute A2
German Motorway (Autobahn) - one of the world's earliest motorways
An autobahn with 4 lanes in each direction of travel for 21 km (13 mi). The section between Zeppelinheim and Darmstadt is the oldest Autobahn.
The A 3 in 1991
Dynamic traffic signs on an Autobahn.
A1 south of Katerini
A2 exit near Kozani
Aerial view of an A6 interchange north of Athens
Eastern section of M0
M1 between, Vértes and Gerecse Mountains
M7 motorway in Köröshegyi völgyhíd
M1 - M7 common phase, near Budapest
The A14 near Forlì.
Dynamic traffic signs on an Autostrada.
A2 motorway near Taujėnai
Motorway junction with U-turns. A2 motorway near Raguva.
Dynamic Route Information Panel (DRIP) on Dutch A13 freeway during evening rush hour
A4 near Zalas, opened in 1983
Interchange of A1 and A4 near Gliwice, the largest motorway junction in Central Europe
Rędziński Bridge
Wrocław Stadion junction
A5 (Lisbon-Cascais) motorway, inaugurated in 1944 as the first motorway in Portugal
A1 (Lisbon-Oporto) motorway, the main road link between the two largest cities of the country
Corgo viaduct, part of the A4 (Oporto-Bragança) motorway
Tunnel at the A27 (Ponte de Lima-Viana do Castelo) motorway
The A10 motorway crossing through the hills of Transilvania
A1 motorway near Sibiu
A2 motorway closing up on the Cernavodă interchange
Arad West interchange under construction
Motorway D1 near Spišské Podhradie with Spiš Castle in the background
Tunnel Považský Chlmec on D3 before opening
View of the High Tatras from the D1 near Poprad
Expressway R1 near Nitra
A1 motorway at Vodole
The Medvedjek Slope on the eastern part of the A2 (Lower Carniola)
The toll station at Log pri Brezovici
A1 near Postojna
The M-40 autopista (motorway) is one of the beltways serving Madrid. It is one of the few non-toll autopistas of significant length
The A-5 autovía (expressway) near Navalcarnero, Madrid. Note the mostly nonexistent acceleration lane in the road joining from the bottom right
Modern autovías (expressway) such as the A-66 near Guillena, Seville, offer most, if not all, features that are required by an autopista (motorway)
E22 Motorway westbound towards Karlskrona
The Södra länken Rv-75 ring road in Stockholm
Turkish state road D 750 at Konya junction. Toros Mountains in the background
Otoyol 2 near Ali Sami Yen Stadium, İstanbul
Aerial view of Tuggeranong Parkway in the Australian Capital Territory
Deer Park Bypass on the Western Freeway
The Tasman Highway in Tasmania
The M1 Pacific Motorway is the major road transport link between the cities of Sydney and Brisbane

Controlled-access highway facts for kids

Contents

History

Environmental effects

Images for kids

See also